test equipment « t r o n i x s t u f f

Kit Review – JYE Tech FG085 DDS Function Generator

Introduction

There has been a lot of talk lately about inexpensive DDS (direct digital synthesis) function generators, and I always enjoy a kit – so it was time to check out the subject of this review. It’s the “FG085 miniDDS function generator” from JYE Tech. JYE is a small company in China that makes inexpensive test equipment kits, for example their capacitance meter (my first kit review!) and DSO. The capacitance meter was good, the DSO not so good – so let’s hope this is better than their last efforts.

Assembly

The instructions (AssemblyGuide_085G) are much better than previous efforts, and if you have bought the kit – read them. The kit arrives in a large zip-lock bag, with the following bundle of parts:

The AC adaptor is 100~240V in, 15V DC out. Everything is included with the kit including a short BNC to alligator clips lead for output. The PCBs are very good, with a nice solder mask and silk screen:

and back:

At this point we realise that most of the work is already done. There’s two microcontrollers ATmega48 and ATmega168- one for display and user-interface control, and the other for function generation. It takes only a few minutes to solder in the through-hole parts, headers and sockets:

… then you flip over the PCB and add the LCD:

… followed by the buttons and rotary encoder. From previous research this is the part that causes people a lot of trouble – so read carefully. There’s a lot of buttons – and if they aren’t inserted into the PCB correctly your life will become very difficult. The buttons must be inserted a certain way – they’re “polarised” – for example:

As you can see above, one side has a double-vertical line and the other side has a single. When you fit the buttons to the PCB – the side with the double-vertical must face the left-hand side of the PCB – the side with the DC socket. For example:

Furthermore, don’t be in a rush and put all the buttons in then try to solder them all at once. Do them one at a time, and hold them tight to the PCB with some blu-tac or similar. If they don’t sit flush with the PCB the front panel won’t fit properly and the buttons will stick when in use. So exercise some patience, and you’ll be rewarded with an easy to use function generator. Rush them in and you’ll be very unhappy. I warned you! After fitting each button, test fit the front panel to check the alignment, for example:

Then you end up with nicely-aligned buttons:

… which all operate smoothly when the panel is fitted:

After the buttons comes the rotary encoder. Be very careful when fitting it to the PCB – the data legs are really weak, and bend without much effort. If you push in the encoder, be mindful of the legs not going through the holes and bending upwards. Furthermore, when soldering in the encoder note that you’re really close to an electrolytic – you don’t want to stab it with a hot iron:

The CP2012 chip in the image above is for the USB interface. More on that later. Now the next stage is the power-test. Connect DC power and turn it on – you should be greeted by a short copyright message followed by the operation display:

If you didn’t – remove the power and check your soldering – including the capacitor polarities and look for bridges, especially around the USB socket. Now it’s time to fit the output BNC socket. For some reason only known to the designers, they have this poking out the front of the panel for the kit – however previous revisions have used a simple side-entry socket. Thus you need to do some modifications to the supplied socket. First, chop the tag from the sprocket washer:

… then remove the paper from the front panel:

Now solder a link to the washer in a vertical position:

… then fit the BNC socket to the panel, with the washer aligned as such:

Finally, align the top panel with the PCB so the BNC socket pin and washer link drop into the PCB and solder them in:

If you want to use the servo mode, solder three short wires that can attach to a servo form the three “output” pads between the BNC and USB socket.

Finally, screw in the panels and you’re finished!

Using the function generator

Operation is quite simple, and your first reference should be the manual (manual.pdf). The display defaults to normal function generator mode at power-up – where you can adjust the frequency, offset, amplitude and type of output – sine, square, triangle, ramp up, ramp down, staircase up and down:

The ranges for all functions is 0~10 khz, except for sine which can hit 200 kHz. You can enter higher frequencies, such as up to 250 kHz for sine – but the results aren’t so good.

Instead of filling this review with lots of screen dumps from an oscilloscope to demonstrate the output – I’ve made the following video where you can see various functions being displayed on a DSO:

You can also create signals to test servos, with adjustable pulse-width, amplitude and cycle times. However you’ll need to solder three wires onto the PCB (next to the BNC socket area) to attach to the servo.

According to the user manual and various retailers’ websites – the FG085 can generate frequency sweeping signals. These are signals that sweep from a start to as finish frequency over a period of time. However the firmware on the supplied unit is old and needs updating to enable this function. You can download the firmware in .hex file format from here. Then go and dig up an AVR programmer and avrdude. At the time of writing we had some issues with the signature not being recognised when updating the firmware, and solidly bricked the FG085. Our fault – so when that’s sorted out we’ll update the review – stay tuned.

There is also a USB port on the side – after installing CP2102 drivers in Windows we could connect at 115200 bps with terminal, however all the FG085 returned was the firmware version number. Perhaps later on the designers will update the firmware to allow for PC control. Somehow I wouldn’t bank on it.

Oh – if you’re wondering what DDS is - click here!

Conclusion

It’s an interesting piece of equipment. Putting the firmware upgrade issues to one side, the FG085 does what it sets out to do. During testing it worked well, and we didn’t come across any obvious inaccuracies during use. The price varies between US$43 and $50 – so for that money it’s a good kit. Just take care during construction and you’ll be fine.

The function generator is available in kit form or assembled, with or without panels from China. The kit version with panels is also available from Sparkfun (KIT-11394) and their resellers. Full-sized images available on flickr. This kit was purchased and reviewed without notifying the supplier.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitter, Google+, subscribe for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other – and we can all learn something.

February 6, 2013 Posted by John Boxall | dds, ds2102, function generator, kit review, KIT-11394, learning electronics, rigol, test equipment | dds, digital, direct, ds2102, fg085, frequency, generator, jyetech, kit, KIT-11394, review, rigol, servo, sine, square, staircase, sweep, synthesis, triangle, tronixstuff, wave | 2 Comments

Review: Agilent U1177A IR to Bluetooth Adaptor

In this review we examine the new Agilent U1177A infra-red to Bluetooth adaptor for the Agilent U1272A DMM. You can also use the adaptor with the U1240-series DMMs with the optional adaptor. With some PC or Android device software you can monitor or log data from up to three DMMs. So let’s have a look and see what it’s all about.

Introduction

The adaptor arrives in a small box:

… with the following contents:

It was a relief to see the AAA cells included as we didn’t have any in stock. The yellow document is the China RoHS sheet, and the instructions are short but well detailed. The unit itself is quite small:

To fit the battery or reset the device, the front cover slides open revealing the innards to some degree:

and the rear:

The unit clips soundly to the rear of the DMM, however it does stick out quite a lot:

If you need to leave the meter unattended, you’ll need a level and vibration free surface, as the adaptor can be knocked out relatively easily from the top. The adaptor also blocks the hole at the back which some users may use with a hook or loop for positioning the DMM.

Software and Operation

You can use the U1177 with two platforms – Android and Windows, and we tested both. I’m sure if you have Mac Parallels, etc., that there may be some success there but I haven’t tested them. There are two applications available for Android devices – the mobile logger and mobile meter. You can download them both from the Google Play app – just search for ‘agilent‘, and the results should be

The third app is a game that is somewhat entertaining. We tried the applications on two Android devices – a HTC Velocity running Android 4.0.3 (which failed miserably, the software kept freezing) and a Motorola Xoom MZ601 with Android 3.2. I would say now that the software is marked “Beta” so caveat emptor. The data logging software worked on the Xoom but not the “Agilent Mobile Meter”. Moving forward, the logging software is quite good – you can display a graph, table or statistical value of the incoming data from up to three separate DMMs.

Below is a rough video of using the Xoom with data logging. We first make the Bluetooth connection, then measure resistance of a 1k ohm logarithmic pot, change the view to data table, then stop the logging and email the data. The app can email a .csv file which can be opened with any spreadsheet, etc. Using the app you can label each DMM feed to avoid confusion with the data files in the future.

Using the U1177A with a Windows 7 x64 machine was a lot more successful. You can download the Windows-based software from here (97 MB). After pairing the adaptor with the bluetooth connection software, the Agilent software loads but does not connect. You need to alter the data speed to 19200bps and select the COM port from the drop-down list in the “communication settings” on the left-hand side of the window, as shown below:

You can also use terminal software and AT commands to change the parameters of the U1177A, which is described in the user manual. Moving forward, once connected you can measure and log to your heart’s content. You can display a virtual meter:

Or choose a graphing display mode:

Note the short drop in value to zero as the graph increased on the far-right of the measurement in the image above. This occurs when the meter is changing range, just as the LCD will blink off then on due to the same phenomenon. Finally, you can also display the data as a table, for example:

Finally, you can export the data to a .csv file which can be opened with the usual spreadsheet or text editing software:

Using Windows OS Remote Multimeter Use Data Logging Other connection – hyperterminal etc.

Conclusion

For data logging to a PC that is in Bluetooth range, the U1177A fits the bill. Although you can get a serial to IR cable (and early U1272A owners should have received one when the firmware update was released), the Bluetooth module will certainly be useful when moving around a worksite, or taking remote measurements from extreme temperature or NVH environments. The Android apps need to move out of beta stage – however due to the variety of devices and OS versions in the market this may be a long journey. However considering the price (~Au$52) it is inexpensive enough to keep around just-in-case.

Note – the U1177A was purchased by myself and reviewed without notice. Residing in Australia, ours was purchased from element14.com.

May 29, 2012 Posted by John Boxall | agilent, android, bluetooth, product review, review, test equipment, U1177A, U1272A | agilent, android, bluetooth, data, IR, logger, review, tronixstuff, U1177A, U1272A | 2 Comments

Review – Agilent Infiniivision MSO-X 3024A Mixed Signal Oscilloscope

Hello Readers

In this article we examine the Agilent Technologies Infiniivision MSO-X 3024A Mixed Signal Oscilloscope. Please note that the review unit has the latest version 2.0 firmware (existing owners can upgrade with the free download).

Initial Impressions

Unlike smaller instruments the packaging is plain and non-descript, however the MSO is protected very well for global shipping and arrived in perfect condition. Inclusions will vary depending on the particular model, however all come with a calibration certificate, user guide on CD and a power lead.

Four passive 300MHz probes are included with the MSO-X3024A:

Due to the constant upgrading of the firmware the lack of a printed user manual is no surprise. You can download the manual as well as the service, programming and educational lab guides from the documents section of the product web page - which make good reading to get a feel for the unit.

Now for a tour around the unit. Coming from a smaller DSO or an analogue model, the first thing that strikes you is the display. 8.5” diagonal with 800×480 resolution:

Unlike cheaper brands the larger screen is not extrapolating data from a smaller image – each pixel is separately used. The front panel is clean and uncluttered. Each button and knob feels solid and responsive, and if pressed and held down, a small help window appears with information about the item pressed. Note that each analogue channel has independent controls for vertical position and V/div sensitivity (the minimum sensitivity is 1mV/division). This saves a lot of time and possible confusion when working on time-sensitive applications.

Around the back we find the cooling van ventilation on the left, the IEC AC power socket on the bottom-right, manufacturing data and so on. The fan is just audible, however the noise from a desktop computer drowns it out. On the far right near the top are separate USB connections for device and host mode, and the external trigger input and output sockets. Apart from the trigger out signal the socket can also be set to give a 5V pulse on a mask test failure or the optional WaveGen sync pulse.

Below this is a space for a Kensington lock cable, and the optional modules – the VGA/LAN adaptor or the GPIB bus module. On the right is my old faithful GW 20 MHz analogue CRO.

Finally, there is a compartment on the top of the unit that can hold two probes comfortably, and four at a pinch:

As the unit is can be considered a small computer, it takes time to boot up – just over thirty seconds. (The operating system is Windows CE version 6.0). The user-interface is quite simple considering the capability of the unit. The six soft-keys below the display are used well, and also can call a separate list of options under each button.

When such a list is presented, you can also use the “Push to select” knob on the right hand side of the display to select an option and lock in by pressing the knob in. Below the soft keys from left to right are: BNC output for the optional function generator, digital inputs for logic analyser, USB socket for saving data to a USB drive, probe points for calibration and demonstration use, and four probe sockets. Connections exist that can interface with optional Agilent active probes.

Specifications

This instrument falls within the range of Agilent’s new Infiniivision 3000-series oscilloscopes. The range begins with the DSO-X3012A with 100MHz bandwidth and two channels, through to the DSO-X3054A with 500 MHz bandwidth and four channels. Furthermore the range is extended with the MSO-X models that include a sixteen channel logic analyser.

Some of you will know there is also the Infiniivision 2000-series, and wonder why one would acquire a 3000-series. There are three excellent reasons for doing so:

Waveform update rate is 50000 per second on a 2000, one million per second on a 3000;
Memory depth on a 2000 is 100 kilopoints; 3000s have 2Mpts standard or 4Mpts optional;
Eight vs. sixteen digital channels when specified as an MSO-X model.

For a full breakdown of specifications please download the Agilent data sheet located here.

Getting Started and general use

The process from cutting open the packaging to measuring a signal is quite simple – just plug it in, connect probes and go – however some probe compensation is required, which is explained quite well in the manual. There are strong tilting bales under the front side which can be used to face the unit upwards. At this point the unit is ready to go – you can start measuring by using the Auto Scale function and let the MSO-X3024A determine the appropriate display settings.

However there is no fun in that – the vertical scale can be manually adjusted between 1 mV and 50V per division, the horizontal between 2 nanoseconds and 50 seconds per division. These values can be selected rapidly or (by pressing the knob in) in a fine method for more precise values. If working with more than one channel, each can be labelled using a pre-set description or select a label from a list. One can also alter the display between X-Y, horizontal and roll modes.

Each channel has separate controls for coupling – DC/AC but no GND, as the earth point is shown on the LCD. Impedance can be 1M or 50 ohm. One can also limit bandwidth to 20MHz to remove high-frequency interference.

Capturing data is very easy, you can save images as .png or .bmp files in grey scale or colour , data in .csv form and so on. You can also assign popular functions to a “Quick Action” button – one press and it is done. For example I use this as a “save bitmap” button to send the screen image to the USB drive. If the optional LAN/VGA module is installed screens can be captured by the host computer via the network. Finally there is a very basic file explorer available to find files on the USB drive as well.

Waveforms can also be stored and used later on as references for other measurements. When reviewed they appear as an orange trace – for example R1:

The horizontal zoom mode activated using keys to the right of the horizontal control is very useful. Agilent call this “Mega Zoom” and it certainly works. Consider the following screen shot – the 32.768kHz square-wave from a Maxim DS1307 real-time clock is being analysed:

The time base is 10uS per division – and using the zoom we can get down to two nanoseconds per division and investigate the ringing on fall of the square-wave. This is great for investigating complex signals over short periods. Awesome.

Capturing infrequent events is made simple by the combination of the one million waveforms per second sampling rate, and the use of infinite display persistence. In the following example a clock with very infrequent glitch is being sampled. By setting persistence to infinite, as soon as the infrequent glitch occurs it can be displayed and held on the screen. For example:

Triggering

There is a plethora of triggering options available. Standard modes include: edge, edge then edge, pulse-width (customisable), pattern trigger (for logic analyser – you can create your own patter of high, low, or doesn’t matter with comparison operators for duration), hex bus trigger, OR trigger, customisable rise/fall time trigger, nth edge burst trigger which allows you to nth edge of a burst after an idle time, runt trigger on positive or negative pulse, setup and hold trigger, on video signals (PAL, PAL-M, NTSC, SECAM), and USB packets. Phew. Furthermore, if you have any of the optional decoding and analysis licenses, they include triggering on the matching signal type (see later).

Math modes

Performing math waveforms on analogue channels is done via a seperate Math button, and the operations available are addition, subtraction, multiplication, differentiation, integration, square root and FFT.

Waveform statistics

When the time comes to further analyse your measurement data, there area variety of measurements that can be taken, and they can be displayed individually, such as in the following:

or all in a summary screen:

Or you can manually use the cursors to determine information about any part of a wave form, for example:

Logic Analyser

Everything required is included with the MSO-X3024A for the sixteen channel logic analyser, including a very long dual-head probe cable:

as well as sixteen grabbers and some extension runs:

Setup and use was surprisingly simple, just connect the probe cable head to ground, insert grabbers onto the ends of each channel wire, and connect to the signal pins to analyse. You can have all sixteen channels and the four analogue channels active at once, however when doing so the screen is quite busy. You can adjust the height for each digital channel. Here we are measuring two analogue and eight digital channels:

As always there are many forms of customisation. Automatic scaling is available the same as analogue measurement. You can set the threshold levels for high and low, and presets exist for TTL, CMOS, ECL and your own custom levels. The cable is very well-built (made in the USA) and the socket on the MSO is a standard, very solid IDC connector. Thanks to the use of the IDC connector you could also make your own probes or extension cable for the analyser. Digital channels can also be combined and displayed as a data bus, with the data values shown in hexadecimal or binary – for example:

Options

Both the 2000- and 3000-series Infiniivision units have a variety of options and upgrades available either at the time of purchase or later on. Agilent have been clever and installed all the software-based options in the unit – when required they are “unlocked” by entering a licence key given after purchase. Trial 14-day licenses are generally available if you want to test an option before purchase. You can also upgrade the bandwidth after purchase – for example if you started with a 100MHz a licence key purchase will upgrade you to 200MHz , or 350 to 500MHz. However if you wish to upgrade a 200MHz to 350/500, this needs to be performed at at Agilent service facility. Surprisingly the logic analyser upgrade that converts a DSO-X to an MSO-X is user-installable. For more information on the upgrade options and procedures please visit here.

Memory Upgrade (DSOX3MEMUP)

A simple yet useful option – it doubles the total memory depth to 4 Mpts interleaved.

LAN/VGA Module (DSOXLAN)

This options really opens up the MSO to the world (and is a lot of fun..) – it is inserted into the port at the rear of the unit:

VGA output is very simple – no setup required. Just plug in your monitor or projector and you’re ready to go -for example, with a 22″ LCD monitor:

The educational benefits of the LAN/VGA module are immediately apparent – instead of having twenty classmates huddle around one MSO while the instructor demonstrates the unit, the display can be show on the classroom projector or a large monitor. The MSO display is still fully active while VGA output is used.

LAN connection via Ethernet was also very simple. The MSO can automatically connect to the network if you have a router with DHCP server. Otherwise you can use the Utility>I/O>LAN Settings function to enter various TCP/IP settings and view the MSO’s MAC address.

Once connected you can have complete control of the MSO over your network. Apart from saving screen shots:

There is a “simple” remote control interface that contains all the controls in a standard menu-driven environment:

Or you can have a realistic reproduction of the entire MSO on your screen:

The full remote panel is completely identical – it’s “just like being there”. The ability to monitor your MSO from other areas could be very useful. For example using the mask testing in a QC area and watching the results in an office; or an educator monitoring students’ use of the MSO.

Furthermore you can view various data about the MSO, such as calibration date and temperature drift since calibration, installed options, serial number, etc. remotely via the web interface.

GPIB Module (DSOXGPIB)

This allows you to connect your MSO to an IEEE-488 communications bus for connection to less contemporary equipment.

Segmented Memory Option (DSOX3SGM)

This options allows you to capture infrequent multiple events over time. For example, you want to locate some 15 mS pulses that occur a few times over the space of an hour. All you need to do is set the triggering to pulse-width, specify the minimum/maximum pulse width to trigger from, then hit Acquire>Segmented, the number of segments to use and you’re off. When the pulses have been captured, you can return and analyse each one as normal. The unit records the start time and elapsed time for each segment, and you can still use zoom, etc., to examine the pulse. For example:

Embedded Serial Triggering and Analysis (DSOX3EMBD)

Debugging I2C and SPI buses are no longer a chore with this option. For example with I2C just probe you SDA and SCK lines, adjust the thresholds in the menu option and you’re set. Apart from displaying the bytes of data below the actual waveform, there is a “Lister” which allows you to scroll back and forth along the captured data along with correlating times. In the following example a Maxim DS1307 RTC IC has been polled:

The Lister details all – in the example we sent a zero to address 0×68, which caused the DS1307 to return the seven bytes of time and date data. This is an extremely useful option and is very useful when working with a range of sensors and other parts that use the I2C bus. The SPI bus analysis operates in exactly the same manner. Adding this option also allows triggering on I2C data as well.

FlexRay Triggering and Analysis (DSOX3FLEX)

The optional FlexRay measurement applications offer integrated FlexRay serial bus triggering, hardware-based decoding and analysis. The FlexRay measurement tools help you more efficiently debug and characterize your FlexRay physical layer network by having the ability to trigger on and time-correlate FlexRay communication with your physical layer signals. So if you are working on the ECU of your Rolls-Royce or new BMW 7-series, you can use an MSO that matches the quality of the vehicle under examination. Here is an example of the FlexRay being monitored in the lister:

RS232/UART Serial Decode and Trigger (COMP/MSOX3000-232)

This option allows RS232, 422, 485 and UART decoding and triggering, as well as the use of the Lister to analyse the data. For example:

Advanced Math (DSOX3ADVMATH)

This option adds more math functions to enhance your waveform analysis, including: divide, base-10 logarithm, natural logarithm and exponential.

CAN/LIN Triggering and Serial Decode (DSOX3AUTO)

Again, allows decoding of automotive CAN and LIN bus signals, and the use of the Lister. For example:

Military Standard 1553 and ARINC429 Standards Serial Triggering and Decoding (DSOX3AERO)

The option exists for decoding and triggering of the above bus types. According to Agilent the Mil-STD 1553 serial bus is primarily used to interconnect avionics equipment in military aircraft and spacecraft(!). This bus is based on tri-level signaling (high, low, & idle) and requires dual-threshold triggering, which the 3000X supports. This bus is also implemented as a redundant multi-lane bus (dual-bus analysis), which is also supported by the 3000X.

The ARINC 429 serial bus is used to interconnect avionics equipment in civilian aircraft (Boeing & Airbus). This bus is also based on tri-level signaling (high, low, & null) and requires dual-threshold triggering, which the 3000X supports. Since ARINC 429 is a point-to-point bus, multi-lane analysis is also required to capture both send and receive data. So if you need this capability – Agilent has you covered.

Video Triggering and Analysis Application (DSOX3VID)

The DSOX3VIDEO option provides triggering on an array of HDTV standards, including:

480p/60, 567p/50, 720p/50, 720p/60
1080i/50, 1080i/60
1080p/24, 1080p/25, 1080p/30, 1080p/50, 1080p/60
Generic (custom bi-level and tri-level sync video standards)

The 3000X Series oscilloscope already comes standard with NTSC, PAL, PAL-M, and SECAM support. Example of video analysis:

Audio Serial Triggering and Analysis (DSOX3AUDIO)

And not surprisingly this is an option to allow decoding of and triggering from I2S digital audio data. For example:

Mask Limit Testing (DSOX3MASK)

This is another interesting and useful option, idea for quality testing, benchmarking and so on. First you create a mask by measuring the ideal waveform, and then feed in the signal to be compared with the ideal mask. Mask limit testing can operate at up to 280000 comparisons per second. You can view pass/fail statistics, minimum sigma and so on, for example – a perfect test:

… then a change of frequency for a few cycles:

Furthermore you can specify the number of tests, change source channel, specify action upon errors, etc. Finally you can create and save to USB your own mask file for use later on – which can also be modified on a PC using any text editor software. Or for other monitoring options the external trigger socket on the read of the MSO can be configured to give a 5V pulse on a mask test failure.

If you have the LAN/VGA module you could place the MSO on in a lab or factory situation and monitor the testing over the network using a PC – very handy for QC managers or those who need to move about the workplace and still monitor testing in real time.

20MHz Function Generator/Arbitrary Waveform Generator (DSOX3WAVEGEN)

The “WaveGen” function is a versatile option that offers a highly controllable 20 MHz function generator and arbitrary waveform generator. It offers eleven different types of waveform: sine, square, ramp, pulse, DC, noise, sine cardinal, exponential rise and fall, cardiac and gaussian pulse.

The frequency can be adjusted between 100mHz to 20 MHz in 100 mHz steps; period from 50ns to 10s; full offset, amplitude and symmetry control; as well as logic level preset outputs (such as TTL, CMOS 5V, 3.3V etc.) Finally the WaveGen can be operated independently to normal measurement tasks, which is useful for ideal vs. actual comparisons and so on. Output is from the BNC socket at the bottom-left of the front pane and sync is also availble from the rear BNC socket. The arbitrary waveform generator is very simple to use - and copied waveforms can be edited or have noise added to them to replicate real-world waveforms.

Power Measurement (DSOX3PWR)

This is a power measurement and analysis option that is integrated into the unit and provides a quick and easy way of analysing the reliability and efficiency of switching power supplies. It also includes a user license for U1881A-003 PC-based power measurement and analysis software that provides even more powerful insight into power supply measurement. With this option you can:

Measure switching loss and conduction loss at the switching device (to help improve efficiency)
Analyse dI/dt and dV/dt slew rate (for reliable operation)
Automate oscilloscope set-up for ripple measurements (to eliminate tedious manual oscilloscope set up)
Perform pre- compliance testing to IEC 61000- 3- 2 standards (to reduce compliance testing time)
Analyse line power with total harmonic distortion, true power, apparent power, power factor, and crest factor tests (to quickly provide power quality information)
Measure output noise (ripple)
Analyse modulation using the on- time and off- time information of a Pulse Width Modulation (PWM) signal (to help characterize the active power factor)
Measure how well a circuit rejects ripple coming from the input power supply at various frequencies with the Power Supply Rejection Ratio (PSRR) measurement.

For more indepth explanation of this option download and read the well written manual.

Etch-a-sketch

Well not a feature as such, but it exists if you know where to find it:

Initial Conclusions

There is no doubt that the Infiniivision 3000-series are a great line of instruments. The waveform sample rate, memory size and bandwidth options are very competitive, and the ability to add various options is convenient and also helps lower the final cost for purchasing departments. (Start with the base model then hit them up for the options over time)

However there are a few things that could use improvement. Although the display is excellent – the right-hand column with “Agilent” at the top is always displayed. This is a waste of LCD space and there should be an option to turn it off, allowing waveforms to be displayed across the entire screen. If a $400 Rigol can do this, so should a $5000+ Agilent. The build unit of the unit is good, no problems are evident however it could be a little more “solid”; and the option of a clear shield for the LCD would be a great idea to protect against forceful and dirty fingers.

Furthermore the ground demonstration terminal suffers from metal fatigue very quickly, it already is somewhat chipped and may need replacing if you used it quite often. Finally, it would have been nice to see Agilent include the a carry bag – already people have asked to borrow the unit and to wander around with it in the box is somewhat awkward.

For those who rely on their test equipment will have the peace of mind that Chinese discount suppliers cannot give you – Agilent support exists and will not ignore you once a sale has been made. It doesn’t take long to find a tale of woe on an Internet forum from someone who imported their own “high-spec” DSO via eBay or direct east-Asian sellers only to find there are no firmware updates, competent English-speaking support or warranty of any kind. Furthermore, the ability to combine many functions in the one piece of equipment saves space, time and reduces your support channel back to one supplier. There is also an iPhone “app” that may be of interest – however as an Android user I haven’t tried it.

The saying “Quality is remembered long after price is forgotten” certainly holds true – and at the end of the day combined with the mix of standard and optional features at various price points – the Agilent Infiniivision MSO-X 3024A rises to the top echelon of test equipment.

The Agilent Technologies Infiniivision MSO-X 3024A Mixed Signal Oscilloscope used in this review is a promotional consideration received from Agilent and element-14 via their Road Test program.

Agilent Test and Measurement equipment is available from your local element-14, Farnell or Newark distributor.

Australian readers please note:

Trio Smartcal are the exclusive Australian Agilent distributors for all states except WA and NT – telephone 1300 853 407.

Measurement Innovation for WA and NT – telephone 08 9437 2550

High-resolution images are available on flickr.

Once again thanks for reading, have fun and keep checking into tronixstuff.com. Why not follow things on twitter, Google+, subscribe for email updates or RSS using the links on the right-hand column, or join our Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other – and we can all learn something.

November 2, 2011 Posted by John Boxall | review, test equipment | 2000, 3000, agilent, analyser, analysis, arbitrary, arinc 429, canbus, decode, DSO, dsox3advmath, dsox3audio, dsox3auto, DSOX3EMBD, DSOX3FLEX, dsox3mask, DSOX3MEMUP, dsox3pwr, DSOX3SGM, dsox3vid, dsox3wavegen, DSOXGPIB, DSOXLAN, element-14, farnell, flexray, function, generator, hdtv, i2c, infiniivision, limit, linbus, logic, mask, memory, mil-spec 1553, mixed, MSO, MSO-X 3024A, MSOX3024A, newark, option, oscilloscope, power, review, rs232, rs485, segmented, serial, series, signal, switchmode, testing, triggering, UART, waveform | 2 Comments

Review – Tenma 72-7222 Digital Clamp Multimeter

Hello readers

The purpose of this article is to examine the Tenma 72-7222 Digital Clamp Multimeter supplied for review by element-14/Farnell/Newark. The Tenma is a strongly featured yet inexpensive piece of test equipment – and considerably good value when you consider there is a current clamp for measuring high AC currents. So let’s have a look and see what we have.

Initial Impression

The Tenma arrives in a retail box, and generally nicely packaged. Naturally this has nothing to do with the performance of the meter at all, but at least they made an effort:

Opening up we find a nicely rounded group of items: the meter itself, some no-name AAA cells, test leads, a thermocouple for temperature measurement, a surprisingly articulate and well-written user manual, and the unit itself – all within a nice pouch. Wow – a pouch. Agilent? Fluke? All that money for a DMM and you don’t include a pouch?

Recent test equipment reviewers have made pulling apart the unit part of the review – so here goes… the back comes off easily:

No user-replaceable fuses… instead a PTC. A closer look at the PCB:

A very neat and organised PCB layout. There are plastic tabs that hold the PCB in along with a screw, however the case flexed too much for me to warrant removing the PCB completely. The spring for the clamp meter is locked in nicely and very strong, it won’t give up for a long time. Pulling the clamp base out reveals the rest of the PCB:

Installation of the battery is two stage procedure, first you need to remove a screw and then slide out the rear door:

… then insert the AAA cells into a frame, which is then inserted inside the unit:

The physical feel of the unit is relative to the purchase price, the plastic is simple and could be quite brittle if the unit was dropped from a height. The user manual claims the unit can be dropped from up to a height of one metre. Onto carpet? Yes. Concrete? Perhaps not. However like all test equipment one would hope the user would take care of it whenever possible. The clamp meter is very strong due to the large spring inside the handle, which can be opened up to around 28mm. The included leads are just on one meter long including the length of the probe:

The leads are rated to Category I 1000V (overkill – the meter can’t go that high) and 600 V Category II – “This category refers to local-level electrical distribution, such as that provided by a standard wall outlet or plug in loads (for example, 115 AC voltage for U.S. or 200 AC voltage for Europe). Examples of Measurement Category II are measurements performed on household appliances, portable tools, and similar modules” – definition from from National Instruments. Unlike discount DMMs from unknown suppliers you can trust the rating to be true – otherwise element-14 wouldn’t be selling it.

Unit Specifications

Voltage Measuring Range DC:200mV, 2V, 20V, 200V, 600V
Voltage Measuring Range AC:2V, 20V, 200V, 600V
Current Measuring Range AC:2A, 20A, 200A, 400A
Resistance Measuring Range:200ohm, 2kohm, 20kohm, 200kohm, 2Mohm, 20Mohm
Temperature Measuring Range:-40°C to +1000°C
DMM Response Type:True RMS
DMM Functions:AC Current, AC/DC Voltage, Resistance, Temperature
Ranging:Auto
Display Count:1999
AC Current Range Accuracy:± (1.5% + 5d)
AC Voltage Range Accuracy:± (1.2% + 5d)
Accuracy:± (1.0% + 3d)
Current AC Max:400A
Current Range AC:2A, 20A, 200A, 400A
DC Voltage Range Accuracy1:± (0.8% + 1d)
Resistance Range Accuracy:± (1.0% + 2d)
Temperature Measuring Range:-40°C to +1000°C

The only measurement missed out on is DC current, however there is the Tenma 72-7224 which has DC current and frequency ranges. Finally, all the modes and buttons can be selected while holding the meter with one hand – for both left- and right-handed folk.

Measurement experience

Normally I would compare the measurements against my Agilent U1272A, however it’s out to lunch. Instead, a Fluke 233. First, AC voltage from the mains:

Next, a few DC voltage measurements:

Now for some resistance measurements. Higher values near the maximum of 20M Ohm can take around four seconds to measure:

Forward voltage of a 1N4004 diode:

Now off to the kitchen for some more measurements – first with the thermocouple:

The boiling water test – 100 degrees Celsius (you can also select Fahrenheit if so inclined):

And now to test out the AC current clamp meter function with a 10A kettle at boiling point. First, using the 20A current range:

And then again on the 400A current range:

As always, it’s best to use the multimeter range that more closely corresponds with the current under test. The meter also has a continuity test with a beeper, however it was somewhat slow and would often take around one second to register – so nothing too impressive on that front. The meter can record the maximum value with the grey button, or hold a reading using the yellow button.

Conclusion

The Tenma 72-7222 works as advertised, and as expected. It is a solid little unit that if looked after should last a few years at a minimum. It certainly has a few limitations, such as the 1999 count display, lack of backlight, and the average continuity function. But don’t let that put you off. For the price – under Au$30 – it is a certified deal. If you need a clamp current meter for odd jobs or a casual-use multimeter and you are on a limited budget, the Tenma will certainly prove a worthwhile purchase. Full-size images are available on Flickr.

You can purchase a Tenma 72-7222 from element-14, Farnell and Newark.

Thanks for reading! Have fun and keep checking into tronixstuff.com. Why not follow things on twitter, Google+, subscribe for email updates or RSS using the links on the right-hand column, or join our Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other – and we can all learn something.

[Note - The Tenma 72-7222 Digital Clamp Multimeter was a promotional consideration from element-14/Farnell/Newark]

October 11, 2011 Posted by John Boxall | review, test equipment | 72-7222, 727222, AC, clamp, clampmeter, current, digital, dmm, element-14, high, measurement, meter, multimeter, newark, review, tenma, tronixstuff | 2 Comments

August 2011 Competition Results

Hello Readers

The month of August is now over and hence another competition. There were six questions hidden among the August articles, and for the curious the questions and answers were:

In which country is the Gravitech Nano MP3 board assembled? – United States;
If you had six pushwheel switches, how many numbers greater than zero can be displayed? – 999999;
Which SMD package type is the SAA1064 used on the Gravitech 7-segment shield? – SOIC (also accepted SO-24, SOT-137 1 etc.)
How many LEDs are on the Snootlab Rotoshield when constructed? Five – there are four bi-colour SMD LEDs on the PCB and the user solders in the power LED. Some people count the bi-colours as two LEDs, so I also accepted an answer of nine;
What does I²C stand for? – Inter-integrated Circuit;
What was the CPU speed of the original MITS Altair 8800 computer? – A scorching 2 MHz.

As always we had many entrants, however there can only be two winners. Thank you to all those who took part and kudos to those who answered all the questions correctly. And now …. *drum roll* winner of the first prize is:

Craig from Western Australia who has won a brand-new Freetronics EtherTen!

This is the mother of all Arduino-compatible boards. Designed in Australia and manufactured to the highest quality standards the EtherTen replaces three boards – consider having an Arduino Uno SMD, Ethernet shield with PoE, and a microSD shield – all on the one board. From the Freetronics website:

The EtherTen is a 100% Arduino compatible board that can talk to the world. Do Twitter updates automatically, serve web pages, connect to web services, display sensor data online, and control devices using a web browser. The Freetronics EtherTen uses the same ATmega328P as the Duemilanove and the same Wiznet W5100 chip used by the official Arduino Ethernet Shield, so it’s 100% compatible with the Ethernet library and sketches. Any project you would previously have built with an Arduino and an Ethernet shield stacked together, you can now do all in a single, integrated board.

We’ve even added a micro SD card slot so you can store web content on the card, or log data to it.

All the good things about the Eleven and the Ethernet Shield have been combined into this one device so please see those pages for all the specific details, but the highlights include:

Gold-plated PCB.

Top and bottom parts overlays.

Top-spec ATmega328P MCU.

Mini-USB connector: no more shorts against shields!

D13 pin isolated with a MOSFET so you can use it as an input.

Power-over-Ethernet support, both cheapie DIY or full 802.3af standards-compliant.

Ethernet activity indicators on the PCB and the jack.

10/100base-T auto-selection.

Fully compatible with standard Ethernet library.

Reset management chip.

Fixed SPI behavior on Ethernet chipset.

Robust power filtering.

Sexy rounded corners.

Note that just like our Ethernet Shield with PoE support, the EtherTen provides a number of options for different Power over Ethernet. You can use the supplied jumpers and feed 7-12Vdc down the wire for cheap DIY version, or you can fit our PoE Regulator 24V and feed a bit more voltage down the wire, or you can use our PoE Regulator 802.3AF along with a proper commercial PoE injector or switch. It’s up to you.

And the second winner is Uday K-A from Germany – who has won a brand-new Freetronics LCD & Keypad shield

This LCD and Keypad Shield gives you a handy 16-character by 2-line display, 5 buttons and a controllable backlight, plug it straight in on top of your Arduino board or other project shields.
The display is set behind the shield for a low profile fitment and nice look and we’ve included panel mounting screw holes in the corners.

It’s great when you want to build a stand-alone project with its own user interface that doesn’t require a computer attached to send commands to your Arduino.

Works perfectly in 4-bit mode with the “LiquidCrystal” library included with the Arduino IDE, allowing you to control the LCD with a total of just 6 digital I/O lines. We’ve deliberately picked D4-D9 so that it doesn’t interfere with pins required by other popular products such as the Ethernet Shield and EtherTen, so you can stack this on top of other shields to give you a local display.

The buttons provide “left”, “right”, “up”, “down”, and “select” while using just one analog input. That leaves the other analog inputs free for you to use in your projects.

The LCD backlight is connected to D3 and can be controlled for on/off, brightness and flashing effects.

Features:

16×2 LCD using HD44780-compatible display module (white characters on blue background).

5 buttons on one analog input (A0).

LCD backlight with current limiting, brightness and on/off controllable by D3, can be moved to D2, D10, A1, A2, A3, A4 or A5 for easy project pin compatibility.

Recessed LCD, panel mount screw holes and button layout suitable for panel or cabinet mounting if desired.

Reset button.

Power supply smoothing capacitor.

Gold-plated PCB for maximum durability.

Overlay printed on both the top and the bottom.

Pins used by shield clearly marked, LiquidCrystal library setup reference is on the bottom of the pcb for convenience.

So another month – another competition. The next competition will be announced soon with another group of great prizes.

And of course thanks to our generous competition sponsor Freetronics!

Visit the Freetronics website or resellers to see their full range of quality Arduino-related products.

So have fun and keep checking into tronixstuff.com. Why not follow things on twitter, subscribe for email updates or RSS using the links on the right-hand column, or join our Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other – and we can all learn something.

September 5, 2011 Posted by John Boxall | arduino, competition, microcontrollers, test equipment | arduino, competition, ethernet, etherten, free, freetronics, keypad, LCD, lesson, lessons, shield, tronixstuff, win | Leave a Comment

August 2011 Competition

Hello Readers

The August competition has now closed and the winners will be drawn and notified very shortly. Stay tuned for the September competition!

Time for another competition! To enter is very easy. There will be six questions hidden within articles published in the month of August (but not this one!). Once you have answers to all six, email them to competition at tronixstuff dot com with “August 2011″ in the subject line before 2359h GMT September 4th. On the 5th of September, I will compile a list of people with the correct answers, and randomly select two winners. Please note competition rules at the end of this article.

The first winner drawn will receive a brand new Freetronics EtherTen!

The EtherTen is a 100% Arduino compatible board that can talk to the world. Do Twitter updates automatically, serve web pages, connect to web services, display sensor data online, and control devices using a web browser. The Freetronics EtherTen uses the same ATmega328P as the Duemilanove and the same Wiznet W5100 chip used by the official Arduino Ethernet Shield, so it’s 100% compatible with the Ethernet library and sketches. Any project you would previously have built with an Arduino and an Ethernet shield stacked together, you can now do all in a single, integrated board.

We’ve even added a micro SD card slot so you can store web content on the card, or log data to it.

All the good things about the Eleven and the Ethernet Shield have been combined into this one device so please see those pages for all the specific details, but the highlights include:

Gold-plated PCB.

Top and bottom parts overlays.

Top-spec ATmega328P MCU.

Mini-USB connector: no more shorts against shields!

D13 pin isolated with a MOSFET so you can use it as an input.

Power-over-Ethernet support, both cheapie DIY or full 802.3af standards-compliant.

Ethernet activity indicators on the PCB and the jack.

10/100base-T auto-selection.

Fully compatible with standard Ethernet library.

Reset management chip.

Fixed SPI behavior on Ethernet chipset.

Robust power filtering.

Sexy rounded corners.

Note that just like our Ethernet Shield with PoE support, the EtherTen provides a number of options for different Power over Ethernet. You can use the supplied jumpers and feed 7-12Vdc down the wire for cheap DIY version, or you can fit our PoE Regulator 24V and feed a bit more voltage down the wire, or you can use our PoE Regulator 802.3AF along with a proper commercial PoE injector or switch. It’s up to you.

And of course there is a second prize – the Freetronics LCD & Keypad shield

This LCD and Keypad Shield gives you a handy 16-character by 2-line display, 5 buttons and a controllable backlight, plug it straight in on top of your Arduino board or other project shields.
The display is set behind the shield for a low profile fitment and nice look and we’ve included panel mounting screw holes in the corners.

It’s great when you want to build a stand-alone project with its own user interface that doesn’t require a computer attached to send commands to your Arduino.

Works perfectly in 4-bit mode with the “LiquidCrystal” library included with the Arduino IDE, allowing you to control the LCD with a total of just 6 digital I/O lines. We’ve deliberately picked D4-D9 so that it doesn’t interfere with pins required by other popular products such as the Ethernet Shield and EtherTen, so you can stack this on top of other shields to give you a local display.

The buttons provide “left”, “right”, “up”, “down”, and “select” while using just one analog input. That leaves the other analog inputs free for you to use in your projects.

The LCD backlight is connected to D3 and can be controlled for on/off, brightness and flashing effects.

Features:

16×2 LCD using HD44780-compatible display module (white characters on blue background).

5 buttons on one analog input (A0).

LCD backlight with current limiting, brightness and on/off controllable by D3, can be moved to D2, D10, A1, A2, A3, A4 or A5 for easy project pin compatibility.

Recessed LCD, panel mount screw holes and button layout suitable for panel or cabinet mounting if desired.

Reset button.

Power supply smoothing capacitor.

Gold-plated PCB for maximum durability.

Overlay printed on both the top and the bottom.

Pins used by shield clearly marked, LiquidCrystal library setup reference is on the bottom of the pcb for convenience.

As with any other competition, there needs to be some rules:

Prizes will be delivered via Australia Post domestic or regular international air mail. Winners may elect for other methods upon payment of real cost;
Winners outside of Australia will be responsible for any taxes, fees or levies imposed by your local Governments (such as import levies, excise, VAT, etc.) upon importation of purchased goods;
Prizes may take up to 45 days to be received;
If you have met me John Boxall in person, or you have won a previous competition you cannot enter;
The Judge’s decision is final with regards to any dispute;
Entries will be accepted until 2359h GMT on 4th September 2011.

And of course thanks to our generous competition sponsor Freetronics!

Visit the Freetronics website or resellers to see their full range of quality Arduino-related products.

August 25, 2011 Posted by John Boxall | arduino, competition, microcontrollers, test equipment | arduino, competition, ethernet, etherten, free, freetronics, keypad, LCD, lesson, lessons, shield, tronixstuff, win | 2 Comments

July 2011 Competition

Hello Readers

The July competition has now closed and the winners have been announced. Thank you to all those who entered and stay tuned for the next competition in August!

Time for another competition! To enter is very easy. There will be six questions hidden within articles published in the month of July (but not this one!). Once you have answers to all six, email them to competition at tronixstuff dot com with “July 2011″ in the subject line before 05/08. On the 5th of August, I will compile a list of people with the correct answers, and randomly select two winners. Please note competition rules at the end of this article.

The first winner drawn will receive an ex-review Ikalogic “Scanalogic2” PC-based logic analyser and signal generator:

With the Scanalogic2, you can capture and analyse all sorts of signals, including I2C, CAN bus, SPI, UART, and more. The firmware is user-upgradable and allows the design team to add more features when they are developed. You can even capture data and play it back to recreate situations in the future, or transfer the data to other users for their analysis. For more information please visit the Ikalogic website, or read my quick review of the Scanalogic.

The second winner drawn will receive one brand new Gravitech Arduino Nano:

Made in the USA, the Gravitech Arduino Nano is a very, very small version of our Arduino Duemilanove boards. It contains the same microcontroller (ATmega328) but in SMD form; has all the I/O pins (plus two extra analogue inputs); and still has a USB interface via the FT232 chip. The prize version will have the pins soldered as shown above.

As with any other competition, there needs to be some rules:

Prizes will be delivered via Australia Post domestic or regular international air mail. Winners may elect for other methods upon payment of real cost;
Winners outside of Australia will be responsible for any taxes, fees or levies imposed by your local Governments (such as import levies, excise, VAT, etc.) upon importation of purchased goods;
Prizes may take up to 45 days to be received;
If you have won a previous competition you cannot enter;
The Judge’s decision is final with regards to any dispute;
Entries will be accepted until 2359h GMT on 4th August 2011.

July 28, 2011 Posted by John Boxall | arduino, competition, microcontrollers, test equipment | analyser, arduino, competition, ethernet, free, gravitech, Ikalogic, logic, nano, Scanalogic2, tronixstuff, tutorial, tutorials, win | Leave a Comment

Kit review – High Accuracy LC Meter

Hello readers

Time for another kit review. Lately one of my goals has been to make life easier and in doing so having some decent test equipment. One challenge of meeting that goal is (naturally) keeping the cost of things down to a reasonable level. Unfortunately my eyesight is not the best so I cannot read small capacitor markings – which makes a capacitance meter necessary. Although I have that function within my multimeter, it is often required to read resistors in the same work session.

Thus the reason for this kit review. A day trip to Altronics saw me return with (amongst other things) their High Precision LC Meter kit. The details were originally published in the May 2008 issue of Australia’s Silicon Chip magazine. The meter specifications are:

Capacitance – 0.1pF to over 800 nF with four-digit resolution;
Inductance – 10 nH to over 70 mH with four-digit resolution;
Accuracy of better than +/- 1% of the reading;
Automatic range selection, however only non-polarised capacitors can be measured.

The power drain is quite low, between 8 (measurement) and 17 milliamps (calibration). Using a fresh 9V alkaline battery you should realise around fifty to sixty hours of continuous use. At this point some of you may be wondering if it is cheaper to purchase an LC meter or make your own. A quick search found the BK Precision 875B LCR meter with the same C range and a worse L range for over twice the price of the kit. Although we don’t have resistance measurement in our kit, if you are building this you already have a multimeter. So not bad value at all. And you can say you built it

Speaking of building, assembly time was just under two hours, and the kit itself is very well produced. The packaging was the typical retail bag:

The first thing that grabs your attention is the housing. It is a genuine, made in the US Hammond enclosure – and has all the required holes and LCD area punched out, so you don’t need to do any drilling at all:

The enclosure has nice non-slip rubberised edging (the grey area) and also allows for a 9V battery to be housed securely. The team at Altronics have done a great job in redesigning the kit for this enclosure, much more attractive than the magazine version. The PCB is solder-masked and silk-screened to fine standard:

There are two small boards to cut and file off from the main PCB. We will examine them later in the article. All required parts for completion were included, and it is good to see 1% resistors and an IC socket for the microcontroller:

At first I was a little disappointed to not have a backlit LCD module, however considering the meter is to be battery operated (however there is a DC socket for a plugpack) and you wouldn’t really be using this in the dark, a backlight wouldn’t be necessary. Construction was easy enough, the layout on the PCB is well labelled, and plenty of space between pins. Lately I have started using a lead-former, and can highly recommend the use of one:

Assembly was quite simple, just start with the lower profile components:

… then mount the LCD and the larger components:

… the switches and others – and we’re done:

The only problem at this point was the PCB holes for the selector switch, one hole was around 1mm from where it needed to be. Instead of drilling out the hole, it was easier to just bend up the legs of the switch and keep going:

At this stage one has to cut out two supports from the enclosure, which can be done easily. Then insert the PCB and solder to the sockets and power (9V battery snap). Initial testing was successful (after adjusting the LCD contrast…):

If you look at the area of PCB between the battery and the left-hand screw there are eight pins – these are four pairs of inputs used to help calibrate and check operation of the meter. For example, by placing a jumper over a pair you can display the oscillator frequency at various stages:

Furthermore, those links can also be used to fine-tune the meter. For example one can increase or decrease the scaling factor and the settings are then stored in the EEPROM within the microcontroller. However my example seemed ok from the start, so it was time to seal up the enclosure and get testing. Starting with a ceramic capacitor, the lowest value in stock:

Spot-on. That was a good start, however trying to bend the leads to match the binding posts was somewhat inconvenient, so I cut up some leads and fitted crocodile clips on the end. The meter’s zero button allows you to reset the measurement back to zero after attaching the leads, so stray capacitance can be taken into account.

Next, time to check the measurement with something more accurate, a 1% tolerance silvered-mica 100 picofarad capacitor:

Again, the meter came through right on specification. My apologies to those looking for inductor tests – I don’t have any in stock to try out. If you are really curious I could be persuaded to order some in, however as the capacitance measurement has been successful I am confident the inductance measurement would also fall within the meter’s specifications.

As shown earlier, there were two smaller PCBs included:

The top PCB is a shorting bar used to help zero the inductance reading, and the lower PCB is used to help measure smaller capacitors and also SMD units. A nice finishing touch that adds value to the meter. The only optional extra to consider would be a set of short leads with clips or probes to make measurement physically easier.

When reading this kit review it may appear to be somewhat positive and not critical at all. However it really is a good instrument, considering the accuracy, price, and enjoyment from doing it yourself. It was interesting, easy to build, and will be very useful now and in the future. So if you are in the market for an LC meter, and don’t mind some work – you should add this kit to your checklist for consideration. It is available from Altronics stores and resellers.

April 28, 2011 Posted by John Boxall | kit review, learning electronics, test equipment | 0.1, accuracy, accurate, altronics, capacitance, chip, DIY, equipment, guide, guides, hammond, hecht, henry, high, inductance, K-2533, K2533, kit, lc, LCD, lesson, lessons, meter, micro, milli, neil, pf, pic16f628a, precision, review, silicon, test, tronixstuff, tutorial, tutorials, uh | 18 Comments

Kit review – Current Clamp Meter Adaptor

Hello readers

Time for another kit review. Over the last few days I have been enjoying assembling a useful piece of test-equipment – a Current Clamp Meter adaptor. This kit was originally described in the September 2003 issue of Silicon Chip magazine. The purpose of this adaptor is to allow the measurement of AC current up to around 600 amps and DC current up to 900 amps. A clamp meter is a safe method of measuring such high currents (which can end you life very quickly) as they do not require a direct connection to the wire in question. As you would realise even a more expensive type of multimeter can only safely measure around ten amps of current, so a clamp meter becomes necessary.

To purchase a clamp meter can be expensive, starting from around $150. Therein lies the reason for this kit – under $30 and a few hours of time, as well as a multimeter that can measure millivolts DC/AC.

How the adaptor works is quite simple. It uses a hall-effect sensor to measure magenetic flux which is generated by the current flowing through the wire being measured. The sensor returns a voltage which is proportional to the amount of magnetic flux. This voltage is processed via an op-amp into something that can be measured using the millivolts AC/DC range of a multimeter. As the copyright for the kit is held by Silicon Chip magazine, I cannot give too much away about the design.

John’s soapbox: People may ask “hey, can you send me the schematic? I don’t want to pay for the reprinted article or buy the kit”. My answer will be no. The hobby electronics industry in this country is shrinking every day, so please support Leo and the gang at Silicon Chip by paying for a reprint or Altronics by buying the kit (it’s out of production at Jaycar). The less kits they sell, the less-inclined they will be to produce new kits.

You can purchase a complete kit from Altronics, or build one yourself by following the article in the magazine. The hall effect sensor UGN3503 is now out of production, but according to the data sheet (.pdf), the Allegro A1302 is a drop-in replacement.

Now, time to get started. To make life easier I forked out for the whole kit, which arrived as below:

Upon opening the bag up, one is presented with the following parts:

It is great to see everything required included with a kit. And the extra battery-clamp is a nice bonus. As usual an IC socket was not included, however these can be had for less than five cents each… so I have recently solved that problem by importing a few hundred myself. The hall effect sensor is very small; considering the graph paper below is 5mm square:

The PCB was very well done – to a degree. The solder-mask and silk-screening was up to standard:

… however a few holes needed some adjustment. Doing a component test-fit before soldering really paid off, as none of the holes for the PCB pins were large enough to accept the pins, and one of the sensor socket holes needed some modification:

A small hand-held drill is always a handy thing to have around. Once those errors were taken care of, actually soldering the components to the PCB was simple and took less than ten minutes. The potentiometer VR3 needed to be elevated by 3.5mm so it would fit through the enclosure panel in line with the power switch. As I couldn’t use PCB pins, a few link offcuts from the resistors worked just as well. When soldering the components, start with the low-profile items such as resistors, and finish with the switch and potentiometer:

Now it was time to make the clamp. First up was to cut the iron-powdered toroidal core in half. All I had to do this with was a small hacksaw, so I hacked away at it for about half an hour. This process will make a mess, filings will go everywhere. So you will need some pointless rubbish to catch the filings with:

Each half of the core is placed inside the clamp. Until I am completely happy with the clamp they will be held in with blutac. A lead also needs to be constructed, with the sensor at one end and the 3.5mm stereo plug at the other. Some heatshrink is provided to cover the ribbon cable, but I recommend placing some over the solder joints where the sensor meets the ribbon cable, as such:

Next, the sensor needs to be placed between the two halves of the core – however a piece of plastic slightly thicker needs to sit next to the sensor, to stop the clamp damaging the sensor by closing down on it. Then, using the continuity function of a multimeter, check that there aren’t any shorts in the lead. Feed the newly-constructed lead through the battery clamp in order to keep things relatively neat and tidy, and you should result with something like this:

As you can see I have had a few attempts at cutting the core. The next step was to drill the holes for the enclosure, and then solder the wires that run from the PCB, run them through the hole in the side of the enclosure, and fasten the banana plugs to plug into the multimeter.

Now it was time to start calibration. There are two stages to this, and both are explained well in the instructions. This involves adjusting the trimpots which control the output voltage in millivolts, which can be affected by charge in the human body. Therefore it is recommended to use a plastic screwdriver/trimming tool to make the adjustments:

They are generally available in a set or pack for a reasonable price. The second stage of calibration involves creating a dummy DC current load using a 12v power supply, 5 metres of enamelled copper wire and a 18 ohm 5 watt resistor:

By putting 100 turns of the copper wire around one side of the clamp, putting the resistor in series and looping it into 12 volts, the current drawn will be 0.667 amps. (Ohm’s law – voltage/resistance = current). Then it is a simple task to set the multimeter to millivolts DC and adjust potentiometer VR1 until it displays 66.7 mA:

So there you have it – 66.7 millivolts on the multimeter represents 660 milliamps of current. So 1 amp of current will be 100 millivolts on your multimeter. Excellent – it works! The whole mess was inserted into the enclosure, and I was left with something that looked not terribly unprofessional (time to invest in a label-maker):

It turns out that the thick OFC cable and the battery wouldn’t be able to coexist in the enclosure, so the battery is external.

The current clamp meter kit was an interesting and satisfying kit to assemble. Originally I assumed it would be simple, but it required plenty of drilling, cutting the darn toroid in half, tricky soldering for the clamp lead, and some patience with lining up the holes for the enclosure. Not a kit for the raw beginner, but ideal for teaching with a beginner to improve their assembly skills, or anyone with some experience. Plus it really does work, so money has been saved by not having to buy a clamp meter or adaptor.

As always, thank you for reading and I look forward to your comments and so on. Furthermore, don’t be shy in pointing out errors or places that could use improvement. Please subscribe using one of the methods at the top-right of this web page to receive updates on new posts, follow me on twitter or facebook, or join our Google Group for further discussion.

High resolution images are available on flickr.

[Note - The kit was purchased by myself personally and reviewed without notifying the manufacturer or retailer]

Otherwise, have fun, be good to each other – and make something!

April 12, 2011 Posted by John Boxall | kit review, learning electronics, test equipment | 03, 2003, adaptor, altronics, ammeter, cheap, chip, clamp, core, current, dc, DIY, equipment, guide, guides, iron, K2582, kit, lesson, lessons, measurement ac, meter, multimeter, project, review, september, silicon, test, tronixstuff, tutorial, tutorials | 4 Comments

Review – Agilent U1272A True-RMS Digital Multimeter

This is our review of the Agilent Technologies U1272A water and dust resistant digital multimeter. It’s an extremely well specifed instrument, and according to the Agilent promotional material a better alternative to the venerable Fluke 87V. We also have examined the Bluetooth module.

Initial impression

The retail box as always is impressive and well decorated. Opening it up reveals a range of items:

including the meter itself, a calibration certificate and calibration results sheet, probe set, thermocouple, quick start guide and four AAA cells. It was a little disappointing to not find alligator clip adaptors nor a carrying case. For those interested, a full range of documentation is available here.

The meter measures 207 x 92 x 59 mm (hwd) and is quite solid, not too heavy and surrounded by a good orange non-slip rubber layer. This no doubt helps provide some shock resistance, as this unit has survived a 2.5 meter drop from my ceiling to the concrete. It is refreshing to see that the keypad is laid out in an organised way, much better than the random-looking layout on the U1250 series:

The meter

Installing or changing the the battery (four AAA cells) is easily accomplished, and thankfully the fuses are also in the same compartment. The included AAA cells are thecheaper “GP brand”, and should do for the first few months. The dust and moisture protection is evident as shown by the o-ring seal around the perimeter of the compartment:

As mentioned earlier, the U1272A is water and dust resistant to IP54 specifications – 54 meaning “protected against dust limited ingress”/”protection against water sprayed from all directions – limited ingress permitted.”.

For more information about IP ratings and what they all mean, check out this IP-rating chart.

It is possible to turn the function selector with one hand whether you have the meter standing up or laying on your desk. The included test leads are just over 1200mm in length and are rated at Cat III 1000V, 15A. Two pairs of probes are included, with 4mm and 19mm tips:

Again, it is unfortunate that alligator-clip adaptors nor probes are included – these are very useful especially to those who are colourblind and need to sort resistors or measure tiny through-hole capacitors. Furthermore, a K-tyle thermocouple and non-compensation transfer adaptor are also included:

The thermocouple’s temperature range is -20~200 degrees Celsius, however with an optional thermocouple the maximum temperature can be increased to 1200 degrees C. As for the othermeasurement ranges, they are detailed in the data sheet which you can download here (.pdf).

Furthermore there is a diode test function, and a continuity beeper. The backlight also flashes when using the continuity function which would be very convenient for those working in a noise environment. There has been some discussion around various forums as to the speed of the continuity function, so here is a small video demonstration of it in action:

In use

Although readers would not have any problem using the meter without reading the manual, doing so will illustrate the particular features of the U1272A as well as operation of the menu system that allow various settings to be changed. These can include: beep frequency (!), backlight duration, data communication parameters, default temperature units, scale conversion values, and activating the low-pass filter available when measuring DC voltage and current.

At the risk of shortening the battery life, I extended the backlight duration immediately to thirty seconds; and set temperature units to degrees Celsius. When taking measurements that only require the main numeric display, the ambient temperature is shown in the secondary numeric display. I must admit to discovering another feature by accident, if the leads are in the current and COM terminals and you select a non-current measurement function – the meter will beep like crazy, blink the backlight and show an error message. This is useful when you’re tired and probably should be doing something else.

Measuring AC voltage provides various data upon request. Apart from the RMS voltage value, you can also turn on a low-pass filter which blocks unwanted voltage above 1 kHz.

The frequency measurement function allows the display the frequency, duty cycle and pulse-width when measuring AC or DC current or voltage. Furthermore, you can display both voltage/current and also display the frequency, pulse-width and duty cycle at the same time, for example:

In a previous article the U1272A was used to measure frequency and duty cycle, which you can observe in the following short clip:

Measuring DC voltage is straightforward, and there is also the option to measure both AC and DC components and display them combined or separately, for example:

You can also display voltage as a decibel value relative to 1 mW (dBm) or a reference value of 1V (dBv). And the dB reference impedance can also be set to fall between 1 and 9999 ohms. Another interesting voltage measurement function is “Zlow”. Using this function, the meter changes to a very low input impedance, and can remove “ghost” voltages from the measurement by dissipating the coupling voltage. This function can also be used to test if a battery is still usable, if the voltage of the battery under test decreases slowly, it doesn’t have the capacity to deliver the required voltage. However I wouldn’t put a battery under this test method for too long due to the meter acting close to a short circuit.

Measuring resistance is simply done with the U1272A, and for more precise measurements one can short the probes to measure their resistance then set a null point so your measurements will not be affected by probe resistance. There is also an Agilent feature called SmartOhm which can be used to remove unexpected DC voltages that can add errors to resistance measurements. You can also use SmartOhm to measure leakage current or reverse current for junction diodes. I look forward to spending more time examining SmartOhm.

Furthermore, one can also measure conductance (the reciprocal of resistance) which is measured in Siemens. According to the manual one can measure extremely high resistance values up to 100 gigaohms. Interesting.

Diode measurement works as expected, the standard setting displays the voltage drop across the diode. However by pressing Shift on the meter, you can use the “Auto-diode” function which forward and reverse bias simultaneously using both numeric displays. For example, measuring a 1N4004 diode produces the following display, the forward voltage and the Good/Not good result:

Measuring capacitance is also quite simple, and the manual recommends setting a null value while the probes are open to compensate for residual capacitance. Interestingly the LCD shows when it is charging and discharging the capacitor under test, using the following segments:

Temperature measurement is possible with the included thermocouple and adaptor. Note that the included K-type thermocouple is only rated for up to 200 degrees Celsius, however with an optional unit the meter can measure up to 1372 degrees C. The display can show Fahrenheit as well as Celsius. The meter also shows ambient temperature using the secondary numeric display when it is not in use with other measurement display functions. Finally, measuring AC or DC current is completed as expected, and as noted earlier when switching to another non-current function, the meter will remind you to change the positive lead.

Compared to other meters, there are a few things that irritated me slightly with this unit. The auto-ranging can be somewhat slower than other meters, especially the frequency measurement – it can take around four seconds to measure a constant frequency… my old Tektronix CFC-250 is faster than that. And the exclusion of alligator-clip adaptors and case was disappointing considering the price of the meter. However on a positive note, the meter is supplied with minimal paper documentation, and a full range of manuals, service guides and so on are available for download from the Agilent website.

Update – 14th June 2011

Turns out that many people had similar (and other problems) to myself with their U1272A. They can be solved by updating the firmware via the USB cable. Agilent will send owners of early versions with the affected firmware a free USB cable in order to fix it up. Download this .pdf file with the instructions on how to receive the cable.

Update – 20th June 2011

The USB>DMM cable has arrived and the firmware updated to v2.0. The meter now works as expected – very well. Kudos for Agilent for taking ownership of the problem and sorting it out so rapidly.

Over the last three months I have been using the U1272A and would call it a success. The dual line LCD display really is useful, as well as the low current measurement and especially the Zlow function. There is a short video you can watch that explains a few of the unique features very well. Furthermore, there is a distinct lack of fragility which gives you one less thing to worry about when looking after your tools. Finally there is also the data-logging, however this does require an optional cable. If you are in the market for a full-function electronics multimeter, put this meter on your evaluation list.

High resolution images are available from flickr.

[Disclaimer - the Agilent U1272A in this review is a sample made available by Agilent Technologies via element-14]

April 1, 2011 Posted by John Boxall | agilent, android, bluetooth, review, test equipment, tutorial, U1177A, U1272A | agilent, android, bluetooth, calibration, continuity, digital, dmm, dust, element-14, guide, guides, IP67, lesson, lessons, multimeter, resistant, review, RMS, test, tronixstuff, true, tutorial, tutorials, U1177A, U1272A, water | 2 Comments

« Previous Entries

YouTube

Visit tronixstuff on YouTube for our range of videos
Clock Projects

Zero - blinky the clock
One - DMD clock
Two - Single digit clock
Three - Pillow clock
Four - Scrolling text clock
Arduino Tutorials

Click for Detailed Chapter Index

Chapters 0 1 2 3 4
Chapters 5 6 6a 7 8
Chapters 9 10 11 12 13
Ch. 14 - XBee
Ch. 15 - RFID - RDM-630
Ch. 15a - RFID - ID-20
Ch. 16 - Ethernet
Ch. 17 - GPS part I
Ch. 18 - RGB matrix
Ch. 19 - GPS part II
Ch. 20 - I2C bus part I
Ch. 21 - I2C bus part II
Ch. 22 - AREF pin
Ch. 23 - Touch screen
Ch. 24 - Monochrome LCD
Ch. 25 - Analog buttons
Ch. 26 - Arduino + GSM - part I
Ch. 27 - Arduino + GSM - part II
Ch. 28 - Colour LCD
Ch. 29 - TFT LCD
Ch. 30 - Arduino + twitter
Ch. 31 - Inbuilt EEPROM
Ch. 32 - Infra-red control
Ch. 33 - Control AC via SMS
Ch. 34 - SPI bus part I
Ch. 35 - Video-out
Ch. 36 - SPI bus part II
Ch. 37 - Timing with millis()
Ch. 38 - Thermal Printer
Ch. 39 - NXP SAA1064
Ch. 40 - Push wheel switches
Ch. 40a - Wheel switches II
Ch. 41 - More digital I/O
Ch. 42 - Numeric keypads
Ch. 42a - Keypads II
Ch. 43 - Port Manipulation
Ch. 44 - ATtiny+Arduino
Ch. 45 - Ultrasonic Sensor
Ch. 46 - Analog + buttons II
Ch. 47 - Internet-controlled relays
Ch. 48 - MSGEQ7 Spectrum Analyzer
Arduino Due - first look
Ch. 49 - KTM-S1201 LCD modules
Ch. 50 - ILI9325 colour TFT LCD modules
Ch. 51 - MC14489 LED display driver IC
Search

Search for:
RSS Feeds

Subscribe in a reader
Join my update list!

Enter your email address to receive notifications of new posts by email.

Join 3,842 other followers
Categories
Previous posts

May 2013

M T W T F S S

« Apr

1 2 3 4 5

6 7 8 9 10 11 12

13 14 15 16 17 18 19

20 21 22 23 24 25 26

27 28 29 30 31
Archives
- May 2013
- April 2013
- March 2013
- February 2013
- January 2013
- October 2012
- September 2012
- June 2012
- May 2012
- April 2012
- March 2012
- February 2012
- January 2012
- December 2011
- November 2011
- October 2011
- September 2011
- August 2011
- July 2011
- June 2011
- May 2011
- April 2011
- March 2011
- February 2011
- January 2011
- December 2010
- November 2010
- October 2010
- September 2010
- August 2010
- July 2010
- June 2010
- May 2010
- April 2010
- March 2010

May 2013
M	T	W	T	F	S	S
« Apr
	1	2	3	4	5
6	7	8	9	10	11	12
13	14	15	16	17	18	19
20	21	22	23	24	25	26
27	28	29	30	31

Contact information

email - john at tronixstuff dot com
Google Group

Why not join our discussion group? Fun and learning with electronics!
Australian Electronics!

Buy and support Silicon Chip - Australia's only Electronics Magazine.
Creative Commons

All the original material in this website, unless noted otherwise, is covered under a Creative Commons Attribution-Non Commercial-Share Alike v3.0 license. Please email me if you see any mis-attributions or would like to use my content in different circumstances.
on twitter…
- "Arduino Workshop" will soon be available in Chinese (simplified and traditional), German and Polish... nostarch.com/arduino @arduino 2 hours ago
- @BruceHoult There's a good review of those in May Silicon Chip magazine. 1 day ago
- Australia’s Slow-Motion Car Crash theglobalmail.org/blog/australia… via @TheGlobalMail 1 day ago
- Thanks everyone - logic probe kit review won - altronics.com.au/index.asp?area… 1 day ago
- @Sqrt_2GM_over_R No, only single-ended ADC 1 day ago
Flickr Photos

More Photos
Find me on…

element 14
flickr
friendfeed
Google+
posterous
tumblr
Twitter
vimeo
Whirlpool
Youtube
Interesting Sites

David L. Jones' eev blog
Freetronics Arduino Geniuses!
Silicon Chip magazine Always a great read!
Amazing Arduino Shield Directory
The Amp Hour podcast
EEWeb Elec Engineering Forum
Superhouse.tv High-tech home renovation
Mr Dick Smith OA
Nuclear weapons = global suicide

In a war with nuclear weapons, everybody loses. Please check these out:
Count Down to Zero
The War Game
Threads

t r o n i x s t u f f

fun and learning with electronics

Kit Review – JYE Tech FG085 DDS Function Generator

Review: Agilent U1177A IR to Bluetooth Adaptor

Review – Agilent Infiniivision MSO-X 3024A Mixed Signal Oscilloscope

Review – Tenma 72-7222 Digital Clamp Multimeter

August 2011 Competition Results

August 2011 Competition

July 2011 Competition

Kit review – High Accuracy LC Meter

Kit review – Current Clamp Meter Adaptor

Review – Agilent U1272A True-RMS Digital Multimeter

YouTube

Clock Projects

Arduino Tutorials

Search

RSS Feeds

Join my update list!

Categories

Previous posts

Archives

Contact information

Google Group

Australian Electronics!

Creative Commons

on twitter…

Flickr Photos

Find me on…

Interesting Sites

Nuclear weapons = global suicide

Site info

Follow “t r o n i x s t u f f”

fun and learning with electronics

Please share with others:

Like this:

Please share with others:

Like this:

Please share with others:

Like this:

Please share with others:

Like this:

Please share with others:

Like this:

Please share with others:

Like this:

Please share with others:

Like this:

Please share with others:

Like this:

Please share with others:

Like this:

Please share with others:

Like this:

YouTube

Clock Projects

Arduino Tutorials

Search

RSS Feeds

Join my update list!

Categories

Previous posts

Archives

Contact information

Google Group

Australian Electronics!

Creative Commons

Flickr Photos

Find me on…

Interesting Sites

Nuclear weapons = global suicide

Site info

Follow “t r o n i x s t u f f”