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Make-and-break circuit with adjustable duration, controlled by a foot switch?

Ok, this request is way out there...

Let's start with a spring-loaded foot switch, normally closed.  When you press the pedal, the circuit is opened.  When you release the pedal, it closes the circuit again.  I want to use a foot pedal like this to control a SECONDARY circuit, with subtly different behavior.  Here's how I want the secondary circuit to work:

When someone presses AND HOLDS the pedal, the secondary circuit opens BRIEFLY, and then immediately closes again.

When the person RELEASES the pedal from a depressed state, the secondary circuit opens briefly, and immediately closes again. 

This would repeat ad infinitum.

"Briefly" in this context probably means a fraction of a second.  But to be sure that it will have the intended effect, it might be necessary to fine-tune the duration (i.e., the time the secondary circuit remains "open"), from about 0.2 seconds up to about 1.5 seconds.

I've tried researching things like this, but I'm not an EE so I'm not really sure where to start.

My first thought was to substitute a slow-action DPDT foot switch (break before make) in place of the original foot pedal.  I.e., the new foot pedal starts out as a closed circuit.  As you step down, the circuit is opened, but when you step all the way down, the circuit is closed again.  This might be a very simple way of obtaining the desired behavior.  But one problem with this approach is that the duration of the "open" window would depend on how quickly you push the pedal down.  Also, if you suddenly let off, I presume the pedal would spring back to its original state.  In that case, the duration of the "open" window upon release might be too brief.

The second approach I conceived of might involve relays and a 555 timer circuit.  I've never built anything like this, or anything else on perf board.  I have no idea what I would be getting into.  So I would prefer to find something already assembled and user-adjustable.

A third approach might involve using an arduino.  Again, I'm not an EE.  I've never programmed one or built a circuit around one.  So again, it would have to be something sold commercially, already built and configured for this purpose.

There's a lot of brainpower on this forum.  Can someone please give me a push in the right direction?  Much thanks in advance!

 

 

Last edited by Ted S
Original Post

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