Tag Archive | "altronics"

Kit Review – Altronics/Silicon Chip ISD2590 Digital Message Recorder

Introduction

Every month Australian electronics magazine Silicon Chip publishes a variety of projects, and in February 1994 they published the “90 Second Digital Message Recorder” project. That was a long time ago, however you can still find the kit today at Altronics (and at the time of writing, on sale for AU$26), and thus the subject of our review.

The kit offers a simple method of recording and playing back 90 seconds of audio, captured with an electret microphone. When mounted in a suitable enclosure it will make a neat way of leaving messages or instructions for others at home.

Assembly

The kit arrives in typical Altronics fashion:

Altronics K9570 90 second message recorder kit package

… and includes everything required including IC sockets for the ISD2590 and the audio amplifier:

Altronics K9570 90 second message recorder kit inclusions

Altronics K9570 90 second message recorder kit components

The PCB missed out on silk-screening – which is a pity:

Altronics K9570 90 second message recorder kit instructions PCB front

however it is from an original design from twenty years ago. The solder mask is neat and helps prevent against lazy soldering mistakes:

Altronics K9570 90 second message recorder kit PCB back

Finally the detailed instructions including component layout and the handy Altronics reference guide are also included. After checking and ordering the resistors, they were installed first along with the links:

Altronics K9570 90 second message recorder kit construction

 If you have your own kit, there is a small error in the instructions. The resistor between the 2k2 and the 10uF electrolytic at the top of the board is 10k0 not 2k2. Moving on, these followed by the capacitors and other low-profile components:

Altronics K9570 90 second message recorder kit construction 4

The rest of the components went in without any fuss, and frankly it’s a very easy kit to assemble:

Altronics K9570 90 second message recorder kit finished

 The required power supply is 6V, and a power switch and 4 x AA cell holder is included however were omitted for the review.

How it works

Instead of some fancy microcontrollers, the kit uses an ISD2590P single chip voice recording and playback IC:

Altronics K9570 90 second message recorder kit ISD2590

It’s a neat part that takes care of most of the required functions including microphone preamp, automatic gain control, and an EEPROM to store the analogue voltage levels that make up the voice sample. The ISD2590 samples audio at 5.3 kHz which isn’t CD quality, but enough for its intended purpose.

Apart from some passive components for power filtering, controls and a speaker amplifier there isn’t much else to say. Download the ISD2590 data sheet (pdf), which is incredibly detailed including some example circuits.

Operation

Once you apply power it’s a simple matter of setting the toggle switch on the PCB down for record, or up for playback. You can record in more than one session, and each session is recorded in order until the memory is full. Then the sounds can be played back without any fuss.

The kit is supplied with the generic 0.25W speaker which is perhaps a little weak for the amplifier circuit in the kit, however by turning down the volume a little the sound is adequate. In this video you can see (and hear) a quick recording and playback session.

Conclusion

This kit could be the base for convenient message system – and much more interesting than just scribbling notes for each other. Or you could built it into a toy and have it play various tunes or speech to amuse children. And for the price it’s great value to experiment with an ISD2590 – just use an IC socket. Or just have some fun  – we did.  Full-sized images are available on flickr

And if you enjoyed this article, or want to introduce someone else to the interesting world of Arduino – check out my book (now in a third printing!) “Arduino Workshop”.

visit tronixlabs.com

Have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column, or join our forum – 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.

Posted in altronics, ISD2590, K9570, kit, kit review, silicon chip, tronixstuffComments (0)

Old Kit Review – Silicon Chip Transistor Beta Tester

Introduction

After exploring a quiet , dusty electronics store in the depths of suburbia the other week, I came across this kit from Altronics (K2534) which is the subject of this review. The Transistor Beta tester is the second revision of a tester designed by John Clarke for the March 1991 issue of Silicon Chip magazine, and promises to offer a simple way of measuring the gain of almost any NPN or PNP bipolar transistor. But first some public answers to recent feedback…

John – Why do you publish these “Old Kit Reviews”?

They’re more of  a selfish article, like many electronics enthusiasts I’ve enjoyed kits for decades – and finding kits from days gone by is a treat. From various feedback some of you are enjoying them, so I’ll continue with them for fun and some nostalgia. If you’re not interested, just ignore the posts starting with “Old”!

Where’s the schematic?

After publishing a few kit reviews, people have been asking me for the schematics. For kits that are based on magazine articles from Silicon Chip and the like, the details are Copyright and I can’t legitimately give you a copy. You need to contact the magazine or kit supplier. The surviving electronics magazines often run “on the smell of an oily rag” so in order to support them I promote the idea of paying for copies which are obtainable from the magazine. Plus Australia is a small country, where people in this industry know each other through first or second connections – so I don’t want to annoy the wrong people. However Google is an awesome tool,  and if you want to make your own beta tester there are many example circuits to be found – so have fun.

Back to the review – what is “beta”?

Apart from a letter of the Greek alphabet and a totally-underrated form of VCR format, beta is a term used to define the amount of gain of a transistor. From the guide:

Silicon Chip transistor beta tester what is beta

Assembly

Here’s our kit from 1991, rescued from the darkness of the store:

Silicon Chip transistor beta tester packaging

Which contained the nice box, plus all the required components except for an IC socket, and a few screws and mounting nuts that should have been included. The instructions looked to be a photocopy of a photocopy, harking back to the 1980s…

Silicon Chip transistor beta tester contents

Silicon Chip transistor beta tester components

Looks like an off-brand 555 has been used (or substituted), however a bit of research indicated that it is most likely from LG Semiconductor:

Silicon Chip transistor beta tester off brand 555

The PCB was made to the usual standard at the time, just drilled:

Silicon Chip transistor beta tester PCB rear

Silicon Chip transistor beta tester PCB front

The front panel was well done, and kindly pre-drilled by a previous customer. The kit came with a 3mm LED however this mystery person had drilled the hole out for a 5mm:

Silicon Chip transistor beta tester front panel

… but hadn’t cut the oblong for the slide switch wide enough. But the biggest problem was that the PCB was just a smidge too wide for the included enclosure:

Silicon Chip transistor beta tester PCB not fitting

Nevertheless it was time to get started, and the resistors were measured, lined up and fitted:

Silicon Chip transistor beta tester resistors lined up

Then the rest of the components fitted as normal, however they need to stay below the horizontal level of the slide switch bezel:

Silicon Chip transistor beta tester assembly 1

… which was somewhat successful. Then to fit the potentiometer, battery snap …

Silicon Chip transistor beta tester assembly 2

and the test leads:

Silicon Chip transistor beta tester assembly 3

 And we’re finished:

Silicon Chip transistor beta tester finished

How it works

Operation is quite simple, just wire up the test leads to the transistor’s base, collector and emitter – set the PNP/NPN switch and press test. Then you turn the knob until the LED just turns on – at which point the scale indicates the gain.

“Modern-day” replacements

Digital technology has taken over with this regard, and a device such as the one below can not only give the gain, but also the component details, identify legs, and much more:

Silicon Chip transistor beta tester modern tester gain

I’ll be sticking with this one for the time being. Jaycar have discontinued the analyser shown above, but Altronics have the “Peak” unit which looks even more useful.

Conclusion

Well… that was fun. A lot of promise, however with a few details not taken care of the kit was just a bit off. Considering this was around twenty years old and possibly shop-soiled I can’t complain. For the record the good people at Altronics have a great line of kits. Full-sized images and a lot more information about the kit are available on flickr.

And while you’re here – are you interested in Arduino? Check out my new book “Arduino Workshop” from No Starch Press.

ledborder

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, 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.

Posted in altronics, K2534, kit review, test equipment, tronixstuffComments (1)

Kit Review – Altronics 3 Digit Counter Module

Introduction

In this review we examine the three digit counter module kit from Tronixlabs. The purpose of this kit is to allow you to … count things. You feed it a pulse, which it counts on the rising edge of the signal. You can have it count up or down, and each kit includes three digits.

You can add more digits, in groups of three with a maximum of thirty digits. Plus it’s based on simple digital electronics (no microcontrollers here) so there’s some learning afoot as well. Designed by Graham Cattley the kit was first described in the now-defunct (thanks Graham) January 1998 issue of Electronics Australia magazine.

Assembly

The kit arrives in the typical retail fashion:

Altronics K2505 Counter Module Kit

And includes the magazine article reprint along with an “electronics reference sheet” which covers many useful topics such as resistor colour codes, various formulae, PCB track widths, pinouts and more. There is also a small addendum which uses two extra (and included) diodes for input protection on the clock signal:

Altronics K2505 Counter Module Kit instructions

The counter is ideally designed to be mounted inside an enclosure of your own choosing, so everything required to build a working counter is included however that’s it:

Altronics K2505 Counter Module Kit parts

No IC sockets, however I decided to live dangerously and not use them – the ICs are common and easily found. The PCBs have a good solder mask and silk screen:

Altronics K2505 Counter Module Kit PCBs

Altronics K2505 Counter Module Kit PCBs rear

With four PCBs (one each for a digit control and one for the displays) the best way to start was to get the common parts out of the way and fitted, such as the current-limiting resistors, links, ICs, capacitors and the display module. The supplied current-limiting resistors are for use with a 9V DC supply, however details for other values are provided in the instructions:

Altronics K2505 Counter Module Kit

Altronics K2505 Counter Module Kit

Altronics K2505 Counter Module Kit

At this point you put one of the control boards aside, and then start fitting the other two to the display board. This involves holding the two at ninety degrees then soldering the PCB pads to the SIL pins on the back of the display board. Starting with the control board for the hundreds digit first:

Altronics K2505 Counter Module Kit

Altronics K2505 Counter Module Kit

… at this stage you can power the board for a quick test:

Altronics K2505 Counter Module Kit

… then fit the other control board for the tens digit and repeat:

Altronics K2505 Counter Module Kit

Now it’s time to work with the third control board. This one looks after the one’s column and also a few features of the board. Several functions such as display blanking, latch (freeze the display while still counting) and gate (start or stop counting) can be controlled and require resistors fitted to this board which are detailed in the instructions.

Finally, several lengths of wire (included) are soldered to this board so that they can run through the other two to carry signals such as 5V, GND, latch, reset, gate and so on:

Altronics K2505 Counter Module Kit

These wires can then be pulled through and soldered to the matching pads once the last board has been soldered to the display board:

Altronics K2505 Counter Module Kit

 You also need to run separate wires between the carry-out and clock-in pins between the digit control boards (the curved ones between the PCBs):

Altronics K2505 Counter Module Kit

For real-life use you also need some robust connections for the power, clock, reset lines, etc., however for demonstration use I just used alligator clips. Once completed a quick power-up showed the LEDs all working:

Altronics K2505 Counter Module Kit

How it works

Each digit is driven by a common IC pairing – the  4029 (data sheet) is a presettable up/down counter with a BCD (binary-coded decimal) output which feeds a 4511 (data sheet) that converts the BCD signal into outputs for a 7-segment LED display. You can count at any readable speed, and I threw a 2 kHz square-wave at the counter and it didn’t miss a beat. By default the units count upwards, however by setting one pin on the board LOW you can count downwards.

Operation

Using the counters is a simple matter of connecting power, the signal to count and deciding upon display blanking and the direction of counting. Here’s a quick video of counting up, and here it is counting back down.

Conclusion

This is a neat kit that can be used to count pulses from almost anything. Although some care needs to be taken when soldering, this isn’t anything that cannot be overcome without a little patience and diligence. So if you need to count something, get one or more of these kits from Tronixlabs Australia. Full-sized images are available on flickr. And while you’re here – are you interested in Arduino? Check out my book “Arduino Workshop” from No Starch Press – also available from Tronixlabs.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, 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.

Posted in altronics, cmos, counter, K2505, kit, kit review, LED, tronixlabs, tronixstuffComments (1)

Kit Review – Altronics Pocket Oscillator

Introduction

In this review we examine the Pocket Oscillator Kit from Tronixlabs, based on an design from (the now defunct) February and March 1989 editions of Electronics Australia magazine – and manufactured by Altronics. The purpose of this oscillator is to give you a high quality, portable square or sine wave generator that can be used to test audio equipment, speaker response, fool about with oscilloscopes (!), and so on. The prototype basic specifications are as follows:

  • Frequency range: 41~1082 Hz and 735 Hz~18.1 kHz
  • Output: 1.27V RMS sine, 1.45V peak square
  • Load: 1.0V RMS sine into 330 Ω
  • Distortion: 0.16% THD at 1 kHz

Assembly

The kit is packaged in typical form, without any surprises:

Altronics K2544

In the usual Altronics fashion, the instructions are accompanied with a neat “electronics reference sheet” which covers many useful topics such as resistor colour codes, various formulae, PCB track widths, pinouts and more. The kit instructions are based on the original magazine article and include a small addendum which isn’t any problem.

Unlike some kits, everything is included to create a finished product (except for the IC socket):

Altronics K2544 parts

… including a nice enclosure which has the control instructions screen-printed on the lid…

Altronics K2544 enclosure

However at this point I think the definition of a “pocket” is the same used by Sir Clive Sinclair when he had those pocket televisions. At this time I won’t use the enclosure as my drill press is in storage, however look forward to fitting the kit within at a later point. The PCB has a neat solder mask and silk screen:

Altronics K2544 PCB top

Altronics K2544 PCB bottom

Assembly was pretty straight forward, the original design has tried to minimise PCB real-estate, so all the resistors are mounted vertically. The signal diodes take this a step further – each pair needs to be soldered together:

Altronics K2544 diodes

… then the pair is also mounted vertically:

Altronics K2544 diodes mounted

However it all works in the end. The rest of the circuit went together well, and we used our own IC socket for the opamp:

Altronics K2544 assembled PCB

From this point you need to wire up the power, switches and potentiometers:

Altronics K2544 assembly

… and consider mounting the whole lot in the enclosure (or before assembly!):

Altronics K2544 lid

However as mentioned earlier, I just went for the open octopus method for time being:

Altronics K2544 finished

How it works

The oscillator is based around the Texas Instruments TL064 opamp, and due to copyright I can’t give you the schematic. For complete details on the oscillator, either purchase the kit or locate the February and March 1989 edition of Electronics Australia magazine. However the waveforms from the oscillator looked good (as far as they can on a DSO):

Altronics Pocket Audio Oscillator K2544 sine wave output

Altronics Pocket Audio Oscillator K2544 sine wave output

Altronics Pocket Audio Oscillator K2544 square wave output

Altronics Pocket Audio Oscillator K2544 square wave output

Conclusion

The oscillator works well, however the PCB layout could have been a little lot easier on the end-user. It’s time for a redesign, possibly put all the contacts for external switches around the perimeter – and allow space for the diodes to lay normally. Nevertheless – this is a neat kit, and still quite popular after all these years. For the price you get a few hours of kit fun and a useful piece of test equipment. So if you’re into audio or experimenting, check it out. Full-sized images are available on flickr.

Finally, check out tronixlabs.com – which along with being Australia’s #1 Adafruit distributor, also offers a growing range and great value for supported hobbyist electronics from Altronics, DFRobot, Freetronics, Jaycar, Seeedstudio and much much more.

visit tronixlabs.com

As always, have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column, or join our forum – dedicated to the projects and related items on this website.

Posted in altronics, K2544, kit, kit review, tronixstuffComments (2)

Kit review – Altronics Logic Probe Mk II

Introduction

Every month Australian electronics magazine Silicon Chip publishes a few projects, and in this kit review we’ll look at an older but still current example from August 2004 – the 3-state Logic Probe Kit (Mk II). This is an inexpensive piece of test equipment that’s useful when checking digital logic states and as a kit, great for beginners. Avid readers of my kit reviews may remember the SMD version we examined in June… well it wasn’t that much of a success due to the size of the parts. However this through-hole version has been quite successful, so keep reading to find out more

Assembly

The kit is packaged in typical form, without any surprises:

bag

 In typical Altronics fashion, an updated assembly guide is provided along with a general reference to common electronics topics:

bagcontents

 All the required parts are included – except for a 14-pin IC socket and two CR2016 batteries.

parts

 The PCB makes soldering easy with the silk-screen and solder mask:

pcbtop

 However the resistor numbering is a bit out of whack, a few R-numbers are skipped. So before soldering, measure and line up all the resistors in numbered order – doing so will reduce the chance of fitting them in the wrong spot.

pcbbottom

When it comes time to solder the power switch on the end, it’s necessary to clip off two tabs – one at each end of the switch. However this isn’t a problem:

solderswitchon

Soldering in the rest of the components wasn’t any effort at all, they’ve been spaced around the PCB nicely:

gettingthere

 Once they’re in, it’s time to insert the pins that hold the probe (shown on the left below):

pinsforprobe

 A full-sized probe is included with the kit, which you cut down with a hacksaw to allow it to fit on the end of the PCB. Then solder a short wire from the tip’s collar and run it through the body as such:

pinsforprobe2

 At this point, it’s time to break out the butane torch:

blowtorch

… with which you melt down the heatshrink over the tip, then fit it to the PCB and solder the probe wire:

testing

At this point it’s wise to fit the batteries and test that the probe works, as the next stage is to heatshrink the entire circuit to the left of the LEDs:

finished

Use

Using the probe is incredibly simple – however note that it’s designed for working with 5V logic. If you need to use higher voltages the probe can be assembled with slightly different circuit to take care of that eventuality. Moving forward simply clip the lead to GND on the circuit under test, then probe where you want to measure. The LEDs will indicate either HIGH, LOW or the PULSE LED will light when a fault is apparent, or other need for further research into the circuit. Here’s a quick demonstration probing a signal from an Arduino board:

Conclusion

This through-hole version of the logic probe kit was much easier to construct than the SMD version, and worked first time. A logic probe itself is a very useful tool to have and I highly recommend this kit for the beginner who enjoys projects and is growing their stable of test equipment on a budget. You can find the kit at my store – Tronixlabs Australia.

Full-sized images available on flickr.  And if you made it this far – check out my book “Arduino Workshop” from No Starch Press.

Finally, check out tronixlabs.com.au – which along with being Australia’s #1 Adafruit distributor, also offers a growing range and great value for supported hobbyist electronics from Altronics, DFRobot, Freetronics, Jaycar, Pololu and much much more.

visit tronixlabs.com

As always, have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column, or join our forum – dedicated to the projects and related items on this website.

Posted in altronics, K2586, kit, kit review, logic probe, silicon chip, test equipment, tronixstuffComments (2)

Kit review – Altronics/Silicon Chip DC to DC Converter

Introduction

Every month Australian electronics magazine Silicon Chip publishes a variety of projects, and in March 2004  they published the “DC-DC converter” project. Altronics picked it up and now offers a kit, the subject of our review. The main purpose of this converter kit is to allow replacement of expensive PP3 9V batteries with 2 AA cells, to enable a cheaper and longer lifespan over use. With a slight modification it can also act as a trickle-charger for 2 rechargeable AA cells (that can then supply power to the converter) via a plugpack. And there’s some educational value if you’re so inclined, as you can learn about voltage converters as well.

Assembly

As usual for Altronics the kit is in a typical retail package:

packaged

…which includes the detailed instructions (based on the original Silicon Chip article), a handy reference guide and of course the parts:

contents

The PCB has a good silk screen and solder mask:

pcbtop

pcbbottom

and all the required parts are included:

components

It was nice to see plenty of extra black and red wire for modifications or final installations, the battery snap, 2 x AA cell holder and a DC socket for use with the optional plug pack mentioned earlier. That hand-wound inductor was interesting, and I couldn’t help but measure it on the LC meter:

lcmeter

It was supposed to be a 47 uH inductor, so let’s hope that doesn’t cause too much trouble. Assembly was quite straight-forward – just start with the smallest components first and build up. If you’re not going to have the trickle-charge function, heed the notes in the manual and don’t install D2 or R4. The only fiddly bit was the “short as possible” (red) link across the board:

longlink

And after a few more minutes it was finished. The external connections will vary depending on your application – however for the review I’ve got the 9V snap on the input, which makes it easy to connect the 2 AA cell holder to power the converter. Nice to see the holes around the perimeter of the board, which make mounting it more permanently quite easy.

Operation

After a bench clean-up it was time to connect 2 AA rechargeable cells and see what we can get out of the converter. The cells measured 2.77V together before connection, and without a load on the converter the resulting output was 8.825 V:

firsttest

We can live with that. Furthermore the quiescent current (a situation with the power connected and not having a load on the output) was 2.5 mA. Thus it would be a good idea to have a power switch in a real-world environment. Speaking of the real world (!) how much current can you get out of the converter? Generally PP3 battery applications are low current, as the battery itself isn’t good for that much – even an expensive “Energizer Ultimate Lithium” offers only 800 mAh (for $16). So using higher-capacity rechargeable AA cells and this kit will save money.  A table is included with the instructions that shows the possible uses:

tableofuse

According to the table my 2.77V supply should be good for ~80 mA. With some resistors in parallel we made a dummy load of 69 mA and measured 0.37A current draw from the AA cells. Thus the key to this kit – you find a cheaper or more plentiful power supply at a lower voltage to save you the expense of providing the higher voltage.

For example, if you had a pair of Sanyo Eneloop rechargeable AA cells (total 2.4 V at 2 Ah) they would give you around 5.4 hours of life (ignoring the fall-off of voltage towards the end of their charge life – however the eneloops are pretty good in that regard). Whereas a disposable PP3 mentioned earlier would offer around 2.1 hours (at $16) or a rechargeable unit (which offers 8.4 V at 175 mAh) would only last around 25 minutes. Note that you can change two resistors in the circuit to alter the output voltage, and the values have been listed in the instructions for outputs up to 15 V.

Finally, let’s consider the output waveforms from the circuit. With the aforementioned load, here’s the output on the DSO:

output

… and for interest’s sake, the switching output from the TL499:

switchoutput

switchoutputdata

Conclusion

Apart from the described voltage-boosting functions this kit gives the interested builder experience with boost circuits and also the knowledge to create their own versions based on the original design, at a much lower cost than using other boost ICs . If you wanted a permanent certain voltage output, it would be better to breadboard the kit and experiment with the required resistors – then assemble the kit with the new values. And there is money and effort to be saved when subsituting with PP3 batteries. Finally, learning is a good thing!

So – a lot of fun and education for under $20. Purchase it from Altronics and their resellers, or read more about it in the September 2007 edition of Silicon Chip.

Full-sized images available on flickr. This kit was purchased without notifying the supplier.

And if you made it this far – check out my new book “Arduino Workshop” from No Starch Press.

LEDborder

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, 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.

Posted in altronics, boost, converter, dc dc, K6330, kit review, learning electronics, silicon chip, tronixstuffComments (0)

Kit review – Altronics/SC PIC Logic Probe Kit

Introduction

Every month Australian electronics magazine Silicon Chip publishes a few projects, and in this quick kit review we’ll look at an older but still current example from September 2007 – the 3-state PIC Logic Probe Kit. This is an inexpensive piece of test equipment that’s useful when checking digital logic states and as a kit, a challenging hand-soldering effort.

Assembly

The kit is packaged in typical form, without any surprises:

kitpack

As mentioned earlier this kit is an interesting challenge due to the size of the PCB and the use of surface-mount components. The designer’s goal was to have the entire unit fit inside a biro housing (without the ink!). Thus the entire thing is using SMT parts.

Thankfully the LEDs are packaged individually into labelled bags, as alone they’re identical to the naked eye. Although the kit wasn’t expensive, it would have been nice for one extra component of each type – beginners tend to lose the tiny parts. The cost could perhaps be offset by not including the usual solder which is too thick for use with the kit.

parts

Nevertheless with some care assembly can begin. After cleaning the PCB with some aerosol cleaner, it was tacked it to the desk mat to make life a little easier:

pcb

If you want one of those rulers – click here. Before building the kit it occurred to me that the normal soldering iron tip would be too large, so I ordered a tiny 0.2mm conical tip for the Hakko:

newtip

The tip on your average iron may be too large, so take this into account when trying to hand solder SMT components. The instructions include a guide on SMT hand-soldering for the uninitiated, well worth reading before starting.

Moving forward, soldering the parts was a slow and patient process. (With hindsight one could use the reflow soldering method to take care of the SMT and then carefully fit the links to the PCB). The instructions are quite good and include a short “how to solder SMT” guide, a PCB layout plan:

instructions

… along with an guide that helps identity the components:

instructionssmt

When soldering, make sure you have the time and patience not to rush the job. And don’t sneeze – after doing so I lost the PIC microcontroller for a few moments trying to find where it landed. Once the LEDs have been soldered in and their current-limiting resistors, it’s a good time to quickly test them by applying 5V and GND. I used the diode test feature of the multimeter which generates enough current to light them up.

Due to the PCB being single-sided (!) you also need to solder in some links. It’s best to do these before the button (and before soldering any other parts near the link holes), and run the wires beneath the top surface, for example:

links

… and after doing so, you’ll need more blu-tack to hold it down!

gettingthere

One of the trickiest parts of this kit was soldering the sewing needle at the end of the PCB to act as the probe tip – as you can see in the photo below, solder doesn’t take to them that well – however after a fair amount it does the job:

needle

At this point it’s recommended you solder the wires to the PCB (for power) and then insert the probe into the pen casing. For the life of me I didn’t have a spare pen around here so instead we’re going to cover it in clear heatshrink. Thus leaving the final task as soldering the alligator clips to the power wires:

finished

Operation

What is a logic probe anyway? It shows what the logic level is at the probed point in a circuit. To do this you connect the black and red alligator clips to 0V and a supply voltage up to 18V respectively – then poke the probe tip at the point where you’re curious about the voltage levels. If it’s at a “high” state (on, or “1” or whatever you want to call it) the red LED comes on.

If it’s “low” the green LED comes on. The third (orange) LED has two modes. It can either pulse every 50 mS when the logic state changes – or in “latch mode” it will come on and stay on when the mode changes, ideal for detecting infrequent changes in the logic state of the test point.

The kit uses a Microchip PIC12F20x microcontroller, and also includes the hardware schematic to make a basic RS232 PIC programmer and wiring instructions for reprogramming it if you want to change the code or operation of the probe.

Conclusion

The PIC Logic Probe is a useful piece of equipment if you want a very cheap way to monitor logic levels. It wasn’t the easiest kit to solder, and if Altronics revised it so the PCB was double-sided and changed the parts layout, there would be more space to solder some parts and thus make the whole thing a lot easier.

Nevertheless for under $17 it’s worth it. You can purchase it from Altronics and their resellers, or read more about it in the September 2007 edition of Silicon Chip. Full-sized images available on flickr. This kit was purchased without notifying the supplier. And if you made it this far – check out my new book “Arduino Workshop” from No Starch Press.

LEDborder

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, 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.

Posted in altronics, K2587, kit review, logic probe, SMT, soldering, test equipment, tronixstuffComments (2)

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 – the 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:

retailkitss

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:

hammondcasess

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:

pcbss2

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:

partsss1

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:

leadformerss

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

assemble1ss

 

… then mount the LCD and the larger components:

assemble2ss

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

finishedsolderingss

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:

switchlegsss

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…

inittestss

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:

calibrationss

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:

3p9pfss

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:

99pfss

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:

pcbadaptorsss

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 our store – Tronixlabs.com

 

visit tronixlabs.com

… which along with being Australia’s #1 Adafruit distributor, also offers a growing range and Australia’s best value for supported hobbyist electronics from DFRobot, Freetronics, Seeedstudio and much much more.

As always, have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column, or join our forum – dedicated to the projects and related items on this website.

Posted in K2533, kit review, LC meter, test equipment, tronixlabsComments (18)

Kit Review – Silicon Chip Low Capacitance Meter adaptor for DMMs

Hello readers

Time again for another kit review. In the spirit of promoting all things electronic and Australian, we’re going to look at a kit that was published in our electronics magazine Silicon Chip (March 2010) – their Low-capacitance meter adaptor for DMMs. Simply put, it converts capacitance (from a theoretical 1 picofarad) to millivolts, which you can then read with almost any digital multimeter. This is useful as even more expensive multimeters (such as my Fluke 233) only measure down to 1 nanofarad (1000 picofarads). Although this kit is available on the Australian market, the retailers will export to those abroad. If you are outside Australia and having trouble sourcing one, send me an email. Moving on…

Here is our unassuming finished product:

finishedss5

Please note that this is not an open-source product, so you need to either purchase the kit of parts, or a back-issue of Silicon Chip magazine, March 2010 for the schematic and instructions. Now it is time to get started. But before that, how does it work?

Without giving too much away, a very rough explanation would be that a square wave signal is formed, then cleaned up through a Schmitt trigger-inverter. This square wave is then split into two, one signal passing through the capacitor under test and some resistors, and the other signal passing through a calibration variable capacitor and the same value resistors – thereby both signals pass through two different RC circuits. Finally the two signals are fed through a XOR gate, which creates a series of positive pulses that are a function of the capacitor under test.

Kit assembly was not that difficult, like anything just take your time, read the instructions carefully, and don’t rush things. If you are happy with your through-hole soldering skills, and have a power drill, this kit will be easy for you to work with. Unusually for some kits, this one comes with almost everything you need:

partsss3

The quality of the included housing is very good, there are metal threaded inserts for the screws; and even through the ICs are simple 74xx-series, sockets have been included. Resistors are metal film, the trimpots are enclosed multiturns – all very nice. I am a little disappointed with the housing/adhesive label combination however, in the past various kits from Jaycar would have a box with a nice silk-screened, hole-punched front panel. Such is life. The PCB is solder-masked and silk-screened, however a little less denser than PCBs from other kit suppliers:

pcbss1

And thus brings a slight issue with the housing and the PCB – either the PCB is too wide, or the box is too narrow. A quick clip of the PCB with some cutters will fix that:

filedpcbss

The instructions are quite good – they are a reprint of the magazine article, and slightly modified by the kit production company. Furthermore, the silk-screening on the PCB makes things a breeze. The simple passives were easy to install, however take care not to overheat the variable capacitor, their casings can melt rather quickly:

resiscapsss

Following that, the ICs were inserted, and the rotary switch. From experience, one should trim the shaft down to about a 25mm length before soldering it into the board. Take very good care when placing the rotary switch, there is a lump on the switch which matches the small circle at 8 o’clock on the PCB diagram. Finally, don’t forget to alter the switch so it only has four selections. Soldering it in can look difficult, but is not. Just push it into the PCB, checking it is flush, even and all the way in. Then bend a couple of the pins over, invert the PCB and solder away – as such:

solderrotaryss

Now it is time to start on the enclosure. Each end has two banana-type sockets, the left are the full binding-post, and the right are just sockets. Carefully mark where you want to start the holes – the positions are vertically half-way, and horizontally 15mm in from the edge, however double-check yourself. Always check the fit of the socket while drilling, as it is easy to go too far and make the holes too large – at which point you’ll have to buy another enclosure. Once you have the sockets fitted – on the left:

left-endss

and on the right:

right-endss

… you will need to solder the socket rear to the PCB pins (left) and a small link to the PCB pins (right). It is important to get a good, solid connection – as these sockets may come under a lot of use later on. Next it is time to start on the housing. If you can, photocopy the label so you have a drilling template:

labelsss

You will notice in the above photo one of my favourite tools, a tapered reamer. Using that, you can carefully turn a small hole into a larger hole, without risking making a mess with a drill. Again, cut the rotary switch’s shaft before soldering:

drilledboxss

And as punishment for using twitter at the same time, I had ended up drilling the back instead of the front. D’oh. However cosmetic appearance is secondary to functionality, so all is well. Next was to install the PP3 battery snap. The battery will be a tight fit, so a length of heatshrink has been supplied in order to avoid the battery case shorting with the PCB pin:

pp3snapss

And finally we have finished soldering:

donesolderingss

Now it is time for calibration. And for me to get a little cranky, which is quite rare as I am somewhat easygoing. Calibration requires three 1% tolerance capacitors, 100 pF, 1000 pF and 10000 pF. And they are not included with the kit. And can not be purchased from any of the kit retailers. So they had to be ordered from Farn… element-14 at a reasonable expense. Considering the kit production company also imports, wholesales and retails electronic components, they could have bought a volume of these special capacitors and added a few dollars to the price of the kit. Such is life. So here are the little buggers:

calibrationcapsss

From top to bottom:

  • Silvered-mica 100 picofarad 1% tolerance, element-14 # 1264880, RS # 495745;
  • Polystyrene 1000 picofarad 1% tolerance, element-14 # 9520651, RS # 495868 (silvered mica) and
  • Polystyrene 10000 picofarad 1% tolerance, element-14 # 3358951, RS # 495953 (silvered mica)

However it is worth the effort to chase them down. There is no point using this kit if you calibrate with normal capacitors; their tolerance can be as much as 20 percent either way. Thankfully the calibration process is quite simple. You will need a small, plastic flat-blade screwdriver to make the adjustments, as your body has stray energy which can alter the capacitance measurements.

Before starting, connect your multimeter to the output sockets and set the range to millivolts – then adjust the variable capacitor until you have the meter display as close to zero as possible. This is used to ‘null out’ stray capacitance. Next, set the dial to A, connect the 100 pF capacitor to the input posts, and adjust VR3 until the meter displays one volt DC – this represents 100.0 picofarads:

cal1ss

I could not for the life of me get this to 1 volt. After fitting the case at the end, I tried again with the case on with the same result. It is very important to get the capacitor as close as possible to the binding posts, with such small values stray capacitance can affect the result. However in my line of work, one-tenth of a picofarad is not relevant. For now. Next, set the dial to B, connect the 1000 pF capacitor, and adjust VR2 until the meter displays 1 volt – this represents 1000 picofarads:

cal2ss

Excellent – spot on. Unfortunately the leads on my 10000 pF capacitor were not long enough to attach into the binding posts, so that step had to be passed. I will have to re-order the correct part next week and calibrate then. However the other two setting are basically working perfectly, which is a good indication for the general performance of the kit. Kudos to Jim Rowe from Silicon Chip magazine for this design. Before closing up the enclosure, I decided to wrap the battery with some paper, as having it  rub up against other parts is not a good idea:

battpaperss

Now for a test run – time to measure the smallest capacitors I have in stock, first a 4.7 picofarad ceramic:

4p7ss

and next, a 12 picofarad ceramic:

12p0ss

Excellent, we can call these readings a success. I was also quite amazed that the tolerance of the cheap ceramic capacitors was so low. Note that in real-life, you may not be able to have the capacitor under test directly connected to the binding posts. In these cases you will need a short set of heavy-gauge leads to the test capacitor. If you do this, you will need to adjust the variable capacitor to reset the display to account for stray capacitance in the leads.

In conclusion, this kit has proved very successful, with regards to assembly, the quality of components and instructions, and of course the final result. I made a few errrors with regards to the housing, but that didn’t affect the final result. And for less than fifty Australian dollars, I have a very low value capacitance meter. However in due course I would consider the purchase of a full LCR meter for greater accuracy and ease of frequent use (some can measure down to 0.1 picofarad). But for the time being, this has been an excellent, educational  and affordable solution. You can purchase the kit directly from Jaycar. High resolution images are available on flickr.

So have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, 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 kit was purchased by myself personally and reviewed without notifying the manufacturer or retailer]

Posted in capacitance meter, jaycar, KC5493, kit review, learning electronicsComments (2)


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