Tag Archive | "4511"

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)

Quick Project – 20th Century Electronic Dice

In this tutorial we make electronic dice without using a microcontroller!

Updated 18/03/2013

After publishing an article which described the design of an electronic die (dice), one of my twitter followers said that they made them in the past just with a 555 timer IC and a 4017 logic IC. A fair point, as one does sometimes get carried away with microcontrollers sometimes. Just to show that I haven’t lost touch, here is a basic rendition of the die project again but without any of that fancy microcontroller jibber-jabber. I will just present the schematic and demonstration, however if you want to make one on some protoboard, doing so should be quite simple.

First off, here is the schematic. I really should learn to use Eagle or somesuch, but a pen and paper is so much quicker:

die1schemss

Now what is happening here? I’m glad you asked. On the left we have a 555 timer in astable mode. For more information about 555 ICs, please visit our part review. When the user presses SW1, power is applied to the 555 and it merrily sends out pulses from pin 3. To increase the speed of the pulses, decrease the values for R1 and R2.

The pulses are received into IC2, a “4017 five-stage Johnson decade counter”. [data sheet] This is still a very old yet useful IC. It has ten output pins, Q0~Q9. Every time the 4017 receives a pulse, starting from power-on or a reset, starting from Q0 it sets an output pin to high (pins default to low). We have sourced LEDs D1~D6 from the first six output pins on our 4017. So when it receives the fast pulses from the 555, it quickly blinks the LEDs in order. When the user releases SW1, the pulses stop arriving from the 555, and the 4017 stops counting – and leaves the current pin HIGH so we can read the value. And here it is in real life:

die1boardss

The parts list:

  • R1, R2 – 82k ohm resistors
  • R3 – 1.8k ohm resistor
  • C1, C3 – 100 nF polyester capacitors
  • C2 – 10nF polyester capacitor
  • D1~D6 – typical LEDs of your choice
  • IC1 – 555 timer IC
  • IC2 – 4017 CMOS counter IC
  • SW1 – normally-open button
  • 5 V power supply (use an LM7805 regulator if 5 V not available)

There are a few things to take note of if building this circuit. The 4017 IC is quite prone to static, so please take care. Furthermore, all unused output pins need to be connected to ground. (Yes, I missed that in the schematic for pin 9). And finally, you can only source 10mA per output pin, which explains the higher than usual value for R3.

Quick note: In the past we have discussed capacitors and their use for smoothing noise from DC current. The circuit above is a perfect example – the 4017 is quite susceptible to noise and will not count properly without C3 between 5V and GND.

Finally, in the spirit of this article, less is more. We could use another 555 in a monostable configuration to limit the running time of the astable 555 pulse-generating timer, but a human can do that with their digits. Furthermore, a reset button could be added onto the 4017, so that’s up to you. Finally, here it is in action:

So there. However you can now see the advantages of using a microcontroller. Each extra function or ‘trick’ created by a line or two of code with our new die could require an exponential amount of hardware, power consumption, board space and possibly a total redesign. However doing it ‘the old way’ is interesting and helps prototyping practice and troubleshooting.

But while we have all of these parts out, we’ll have a little more fun… let’s do it with an actual number being display, instead of a flurry of blinking LEDs. We still need the 555 timer to create our pulses, so that remains the same:

die2aschemss

and here is the rest of the circuit:

die2bschemss

So in this example, the 555 is sending out pulses on request via SW1. However this time, the 4518 BCD counter [data sheet] receives those pulses, counts them (from zero to nine then repeat) and converts the current value to binary-coded decimal. Next, the BCD value is sent over to the 4511 BCD to 7-segment driver IC [data sheet]. This IC converts reads the BCD and sets outputs that are suitable for driving 7-segment LED modules. These outputs are sent via 330 ohm resistors to protect the LED segments. Then finally, the digit zero to nine can be displayed on the LED unit.

With some trickery we could limit this display to the numbers 1~6, if you want to do that go for it. So in this case our ‘die’ has in fact 10 values. I’m sure there are some games that could make use of it. Anyhow, here it is in real life:

die2boardss

You may be wondering what happened to R3~R9. In this case I am using a DIP resistor array. This is just eight resistors in one package, which makes life easier.

The parts list:

  • R1, R2 – 82k ohm resistors
  • R3~R9 – 330 ohm resistors
  • C1, 100 nF polyester capacitor
  • C2 – 10nF polyester capacitor
  • D1 – common-cathode 7-segment LED display
  • IC1 – 555 timer IC
  • IC2 – 4518 CMOS counter IC
  • IC3 – 4511 BCD to 7-segment IC
  • SW1 – normally-open button
  • 5V power supply (use an LM7805 regulator if 5V not available)

And here it is in action:

You can now see why the Arduino and other microcontrollers have taken off in popularity. They really do lighten the load with regards to planning and hardware construction. However it is enjoyable to do things the old way sometimes, ergo this article. If you are interested in articles like this one that use digital electronics, please let me know via the Google Group and there will be more projects similar to this one, but in greater detail. One day I may even pull the finger out and make a TTL clock…

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 4017, 4511, 4518, 555, dice, learning electronics, tutorialComments (2)


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