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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, tronixstuff1 Comment

Australian Electronics Nostalgia – Talking Electronics Kits

Introduction

From 1981, Australian electrical engineer Colin Mitchell started publishing his home-grown electronics magazine “Talking Electronics”. His goal was to get people interested and learning about electronics, and more so with a focus on digital electronics. It was (and still is) a lofty goal – in which he succeeded. From a couple of rooms in his home the magazine flourished, and many projects described within were sold as kits. At one stage there were over 150 Talking Electronics kits on the market. You could find the books and kits in retail outlets such as Dick Smith Electronics, and for a short while there was a TE store in Moorabbin (Victoria). Colin and the team’s style of writing was easy to read and very understandable – but don’t take my word for it, you can download the magazines from his website (they’re near the bottom of the left column). Dave Jones recently interviewed Colin, and you can watch those for much more background information.

Over fifteen issues you could learn about blinking LEDs all the way to making your own expandable Z80 board computer, and some of the kits may still be available. Colin also published a series of tutorial books on electronics, and also single-magazine projects. And thus the subjects of our review … we came across the first of these single-issue projects from 1981 – the Mini Frequency Counter (then afterwards we have another kit):

cover

How great is that? The PCB comes with the magazine. This is what set TE apart from the rest, and helped people learn by actually making it easy to build what was described in the magazine instead of just reading about it. For 1981 the PCB was quite good – they were silk-screened which was quite rare at the time:

pcb

pcbrear

And if you weren’t quite ready, the magazine also included details of a square-wave oscillator to make and a 52-page short course in digital electronics. However back to the kit…

Assembly

The kit uses common parts and I hoard CMOS ICs so building wasn’t a problem. This (original) version of the kit used LEDs instead of 7-segment displays (which were expensive at the time) so there was plenty of  careful soldering to do:

LEDsin

And after a while the counter started to come together. I used IC sockets just in case:

almostthere

The rest was straight-forward, and before long 9 V was supplied, and we found success:

powerup

To be honest progress floundered for about an hour at this point – the display wouldn’t budge off zero. After checking the multi-vibrator output, calibrating the RC circuits and finally tracing out the circuit with a continuity tester, it turned out one of the links just wasn’t soldered in far enough – and the IC socket for the 4047 was broken So a new link and directly fitting the 4047 fixed it. You live and learn.

Operation

So – we now have a frequency counter that’s good for 100 Hz to the megahertz range, with a minimum of parts. Younger, non-microcontroller people may wonder how that is possible – so here’s the schematic:

schematic

The counter works by using a multi-vibrator using a CD4047 to generate a square-wave at 50, 500 and 5 kHz, and the three trimpots are adjusted to calibrate the output. The incoming pulses to measure are fed to the 4026 decade counter/divider ICs. Three of these operate in tandem and each divide the incoming count by ten – and display or reset by the alternating signal from the 4047. However for larger frequencies (above 900 Hz) you need to change the frequency fed to the display circuit in order to display the higher (left-most) digits of the result. A jumper wire is used to select the required level (however if you mounted the kit in a case, a knob or switch could be used).

For example, if you’re measuring 3.456 MHz you start with the jumper on H and the display reads 345 – then you switch to M to read 456 – then you switch to the L jumper and read 560, giving you 3456000 Hz. If desired, you can extend the kit with another PCB to create a 5-digit display. The counter won’t be winning any precision contests – however it has two purposes, which are fulfilled very well. It gives the reader an inexpensive piece of test equipment that works reasonably well, and a fully-documented project so the reader can understand how it works (and more).

And for the curious –  here it is in action:

[Update 20/07/2013] Siren Kit

Found another kit last week, the Talking Electronics “DIY Kit #31 – 9V siren”. It’s an effective and loud siren with true rise and fall, unlike other kits of the era that alternated between two fixed tones. The packaging was quite strong and idea for mail-order at the time:

kitbox

The label sells the product (and shows the age):

kitlabel

The kit included every part required to work, apart from a PP3 battery, and a single instruction sheet with a good explanation of how the circuit works, and some data about the LM358:

kitparts

… and as usual the PCB was ahead of its’ time with full silk-screen and solder mask:

pcbtop

sirenpcbbottom

Assembly was quite straight-forward. The design is quite compact, so a lot of vertical resistor mounting was necessary due to the lack of space. However it was refreshing to not have any links to fit. After around twenty minutes of relaxed construction, it was ready to test:

PCBfinished

finished

It’s a 1/2 watt speaker, however much louder than originally anticipated:

Once again, another complete and well-produced kit.

Conclusion

That was a lot of fun, and I’m off to make the matching square-wave oscillator for the frequency counter. Kudos to Colin for all those years of publication and helping people learn. Lots of companies bang on about offering tutorials and information on the Internet for free, but Colin has been doing it for over ten years. Check out his Talking Electronics website for a huge variety of knowledge, an excellent electronics course you can get on CD – and go easy on him if you have any questions.

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 australia, counter, digital, electronics, frequency, history, kit review, learning electronics, magazine, talking, talking electronics, test equipment, tronixstuff, vintage8 Comments


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