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The title says it all.

Something like this except I want to do it with transistors

Is there a discrete circuit that can produce 4 different outputs based on a single tactile switch click?

I'd like to do this with either a discrete design or a 74373 since these are all the parts I have on hand. I'm living in a difficult country to get this stuff delivered to.

Aaron Butkovich
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  • What do you mean by 4 different outputs? Do you want the outputs to be at different frequencies or at different voltage levels? – sai Aug 25 '23 at 01:45
  • I'm assuming that by analog you mean analogous to bistable, not non-digital, because bistables themselves are digital circuits. – Jasen Слава Україні Aug 25 '23 at 01:57
  • @sai The outputs should be similar to a monostable output. Designed to go high when the switch is pressed and to maintain that state until the correct trigger is received. – Aaron Butkovich Aug 25 '23 at 03:20
  • If you can add a simple truth table showing exactly what you expect as input and output someone can better describe what type of logic or a circuit that will fill your requirements. – Nedd Aug 25 '23 at 03:27
  • @JasenСлаваУкраїні Yes, my mistake. I was thinking ahead to when I have multiple outputs and I could have states such as 0,1,2,3,4. – Aaron Butkovich Aug 25 '23 at 03:34

3 Answers3

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Once you get more than two states they are no longer called n-stable multivibrators but instead called counters,

A toggle bistable is the simplest form of counter, but there are plenty of larger examples.

See CD4017 for example that can do up-to 10 stable states.

Alternatively you can chain several toggle bistables to make a binary counter.

If you're wanting to drive these from a tactile switch you may need to de-bounce it.

Jasen Слава Україні
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  • 4017 is perhaps an interesting example, because it has 32 potential stable states, any of which it could take on initially (assuming it is without benefit of an external reset pulse). – Spehro Pefhany Aug 25 '23 at 02:43
  • Didn't Signetics or someone like that have triple-state (not tri-state) logic devices in the 70's? One pin, three defined output voltage levels. – AnalogKid Aug 25 '23 at 04:56
  • some of the garage door opener chips used tri-state sensing inputs for trinary coding – Jasen Слава Україні Aug 25 '23 at 05:55
  • I like this answer because it gives a discrete transistor option that will work for me immediately. 4017 chips are added to cart for my next order. – Aaron Butkovich Aug 26 '23 at 17:10
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Yes. There are tristable, quadristable, etc. multivibrators.

They can be called "ring multivibrators".

Here is one with 3 stages.:

enter image description here

Source

How to extend it to four and more stages is obvious.

Davide Andrea
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The simple answer is yes, but only because the question is so vague.

If by "4 different outputs" you mean four different output voltage levels at a single node, then this can be done with a 2-bit counter driving a simple D/A resistor ladder. This is my first guess at what you are asking about, based on the wording. If a bistable has two possible output voltages, then a tristable should have three ...

Another option is that you are talking about four different points in the circuit, four nodes or four output pins, that cycle through a pattern as the button is pressed repeatedly. In this case, a 4017 can be wired to cycle through anything from 1 to 9 outputs.

As above, a truth table of your required results is critical in answering this question.

AnalogKid
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