I've been toiling away on this idea for weeks now and finally got it working...for the most part. It still doesn't do exactly what I need it to do yet though and I was hoping someone here could give me a hand.

Basically it's a momentary-switch-actuated SPDT switch-actuator built from op amps. Engage the switch and OUT goes high while ~OUT goes low. Engage again and the outputs toggle.



What I really want is for it to essentially work like a T-flip-flop. One pulse to turn on, another to turn off (the pulse ultimately coming from an other momentary switch). Now I suppose I could just replace the existing momentary switch with a mosfet or some such, but I was hoping another op amp in the equation could do the trick (since I'm using LM324 quads anyway). Not sure how that would be done though.

Any ideas?

 

You said you finally got it working "for the most part". What is the part that is not working?

 

Here are a couple of circuits (An apparently unrelated link and promotional information removed by moderator)

 

You said you finally got it working "for the most part". What is the part that is not working?

It currently it works by means of a make/break mechanism. What I'd like is to have it be pulse-driven.

 

Why not use a J-K flip-flop such as CD4027 or 74HC112 with J and K inputs wired to logic-HIGH?

 

Why not use a J-K flip-flop such as CD4027 or 74HC112 with J and K inputs wired to logic-HIGH?

That would work fine I suppose, but partly there's just the curiosity of how it could be done with op amps. Other thing is I've got a whole box full of these little buggers (LM324's) which I'd like to repurpose for the task.

 

Looks like this one will work fine. Let's wait for the OP feedback.

 

How about implementing the second circuit provided by DakLak in post #3, but with and LM324? It toggles.

 

How about implementing the second circuit provided by DakLak in post #3, but with and LM324? It toggles.

Well I'm looking at it, but I still can't see how that could possibly be triggered by a pulse.

Incidentally, I did sort of figure out a way to do this with a slight modification to the circuit on the breadboard. Removed C1 and sending a 2.5V pulse to the output terminal of the lower op amp (not the line marked "out" in the schematic, that is, but the proper output terminal). Anyway, it's glitchy and doesn't work at all in the simulator, so not quite sure if that's going to be a viable solution in the long run...

 

If you want to make it work with an electrical signal rather than a mechanical contact closure you can use something like this.


The circuit in post #3 is not edge sensitive like a T flip-flop. It reads "Press on, hold off latch" but it might give you some satisfaction to get it working

 

If you want to make it work with an electrical signal rather than a mechanical contact closure you can use something like this.

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The circuit in post #3 is not edge sensitive like a T flip-flop. It reads "Press on, hold off latch" but it might give you some satisfaction to get it working

Thanks, I'll give it a go. Cheers!