# 16-Stage Decade Counter Chain - Using two 4017 Chips

I found a way to easily make a decade counter that has more outputs than just 10.

Objective and Motive:
I really like how binary counters can link together in chains. For example, if you have two 8-stage binary counters, you can use them together to easily make a 16-stage binary counter.
I always wanted to do that with decade counters. And today I found a way to do this!
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## Step 1: Gather the Parts

Parts:

• lots of jumper wires
• one 555 timer
• two 0.1 µF capacitors (#104)
• one 10 µF capacitor
• one 1 nF   capacitor (#102)
• five 10KΩ (or anything between 4.7kΩ and 22kΩ)
• three N-channel mosfets
• one switch
• one 5V power supply

With these in hand, you should be ready to make a 16-stage decade counter!

## Step 2: Examine the Schematic

Take a look at this schematic to see how the components fit together.
You can click on the schematic picture to see a full-size version.
The 16 green wires on the right of the schematic are the 16 outputs.
I suggest you put 16 LEDs on those outputs with 1KΩ resistors in series to monitor the outputs of this device.

If you don't know how to read schematics, I suggest following this tutorial:
Collin's Lab: Schematics

## Step 3: Build Your Circuit

Now that you have looked over the schematic, you are ready to build the circuit.
Assemble the circuit on a breadboard using jumper wires to connect components.

If you can pack your LEDs together tightly, it will save you some breadboard space.
In the end, I had to expand to using a second breadboard because my LEDs took up so much space.
I'm getting some LED bar graphs to fix this problem  :)
b8el01810 days ago

I think can use only 1 resistor for all the LEDs because there is only ever 1 LED on at one time. Nice circuit though :)

jensenr30 (author)  b8el0188 days ago

That is an excellent observation.

Thanks.

TimS919 days ago

Great idea.

http://electronicsclub.info/p_trafficlight.htm I have made this circuit & it works great but if you get the amber light time right, the red & green lights are too short, the whole sequence is too quick. I need to extend the red led count by 4 counts & the green by 4 counts & using your idea I think would solve the problem, I can follow a circuit diagram fine but trying to work this out, well when I was young most things still had valves!!!!!

Tim

jensenr30 (author)  TimS918 days ago

That sounds interesting. I think you could do that if you slightly modified my circuit. (i.e. make it an 18-step counter rather than a 16-step one)

18 days ago
​As I say I can follow a diagram fine but need a little help in trying to adapt the two circuits. You say to use 3 N-Channel Mosfets could you be a little bit more precise as to how many amps & volts you used, I looked on one site & there were 43 different types ranging from 12v to 500v. Whatever I do the power source will be a 12v DC transformer which will be running various other lights & signals at the same time.

Tim
jensenr30 (author)  TimS917 days ago

To change it to an 18-step counter, route the reset signal come from pin Q9 instead of pin Q8. That will make the counter have 18 steps rather than 16.

halamka11 months ago
Great -- now hook it up to a memory chip and computer screen .
gprakash11 year ago
Hai friend nice projects you done, and you have a good knowledge,please do me a favour, that how can we construct a circuit that it should be operated when a push button is pressed so that the relay in the circuit will stay on till the push button again pressed, here we should use only a push button which makes a circuit connected when button pressed, and breaks the circuit when removed, please if you have a circuit please send me a mail to gowthamprakash15@gmail.com
Teslaling1 year ago
That is a brilliant design! I think that it is a very efficient way to "add" counters together. Since they count independent of each other, I assume that means that you could also count odd numbers too. For example if I needed to count to 13, I could stop one on the 8th output and the other on the 7th output right?
jensenr30 (author)  Teslaling1 year ago
Exactly right!
On counter could count to 7 (stop on eight) and the other could count to 6 (stop on 7) so that the total equals 13.
It seems you understand the concept of this device perfectly! :D
I'm glad I was able to show how my machine works.
pfred21 year ago
This is interesting. I would have thought the carry out pin would have been used to clock the second counter. I often like using a 74154 if I need 16 outputs too. This way is more compact.
jensenr30 (author)  pfred21 year ago
ooh. The 74154 looks really nice. I might have to use this for my drum machine instead...
Thanks for the info!