(ON)-OFF-(ON) pushbutton?

Thread Starter

Andersons

Joined Sep 28, 2019
25
I’m looking for a pushbutton switch that’s normaly open with two outputs. The first push will close the first output, when the button is released it will open it. The second push will close the second output and when the button is released it will open it. The third push will close the first output again, and so on.

What are these switches called?
 

Tonyr1084

Joined Sep 24, 2015
5,860
If I read this right you want the first push to be the first set of contacts closed but they only stay closed while you hold the switch. Then push the same button and you want the second push to be the second set of contacts closed but only stay closed while you hold the switch. If I read that correct.

If so - I've never heard of a mechanical switch that acts that way. Not saying they don't exist, just I've never heard of such an animal. If you can tell us your application we can come up with some ideas that will suit your application. However, we're not into "free engineering services". No, we're not asking to be paid, that's not why we're here. We're here to HELP you figure out a solution.

Without knowing your application we can't give you better results. But if you start with a drawing or schematic along with some starting ideas we CAN suggest changes, improvements OR alternatives. I already have an idea how I would go about doing this but it would be for digital signals. Those signals can be used to trigger higher amperage devices, but again, we don't know your application. Can you give us a hint?
 

Irving

Joined Jan 30, 2016
1,274
Never seen a switch like that... push-on-push-off are pretty common. Where have you seen what you describe, or is that functionality what you need but can't find?
 

Tonyr1084

Joined Sep 24, 2015
5,860
It sounds like he needs a circuit.
Yeah, that was my thought too. And likely the approach I'd take if I needed a switch to function like that. Something along the lines of a Dual D Flip Flop at the heart of it combined with an AND gate.

But I'm not a free engineer. Heck! I'm not even a "Good" engineer. In fact, I'm not EVEN an engineer. But something so simple, I could handle that. But not for free. The TS (Thread Starter) will have to form an idea and approach then bring it before us. Then we can point him/her in the right direction.
 

Irving

Joined Jan 30, 2016
1,274
How about this... interesting intellectual challenge, but I've not simulated it yet so who knows....

_push1 & _push2 are high going debounced outputs that are high as long as the push button is low, and alternate on each push (U3C & D can be used to invert for low going outputs). Of course they'll need further processing depending on the TS' requirement. U1A debounces low going input (push), U2A debounces high going input (release). U2A is the 'clean' push button and U2B the alternating selection. C3/R5/D1/D2/R4 do a power on reset function.

It may work....

1603142359221.png
 

Tonyr1084

Joined Sep 24, 2015
5,860
Ok if we're going down the flip flop road, push button clocking a cd4013 ..or a CD4017 set to 3.
Wasn't saying the TS wants to go with flip flops. Was saying that off the cuff this was an idea to solve the problem presented. We STILL haven't heard from the TS about application or what his/her thinking is on an approach.

Years back, using a pull chain switch for a fan with High, Medium, Low, Off I used it to wire up two lamps to one circuit (high), then to two DIFFERENT lamps (medium) or ALL FOUR (low). It took some considerable thought about how to wire the switch but I managed to get it done. But it's not in keeping with the "One pushbutton" scenario. Really, to go with a single pushbutton, I'd opt for some sort of electronics.
 

MisterBill2

Joined Jan 23, 2018
8,417
It would be a DPDT alternate-action pushbutton switch. I just fixed a lamp for a friend that had a similar, but not identical, function with a pull chain, one on, the other on, both on, both off.
A garage door opener has a similar function: Push once, open, push again, stop, push again, close, push again, stop. Older electric trains had a relay with a 4-position drum controller that did exactly that, and some garage door openers had a relay to do that.
How much current should the button handle? and what voltage? And how big?
 
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