Thread: Rotary Switch to Variable Timing Circuit?

It all depends on the accuracy & delays you need.
A 555 timer is analog and uses resistor-capacitor combinations for fractions of a second to many 10's of minutes.

Otherwise there are programmable timers - check Jaycar.

Then there's the FB, Arduino, etc.

Yes, the 555 Ive researched quite a bit. But, unfortunately if it requires different sets of res/cap for each setting on the rotary dial, it defeats the purpose of my project. Itll be too large for the small containing space.

I was hoping for a rotary dial which sends different "signals" for each different setting. Hexadecimal seems the only way to accomplish this because the 555 is the only other way, and using a normal switch between res/cap banks, isnt gonna cut it. A chip would read the "signal", i.e. setting, and output a pulse of power for a specific length of time.

Using a dev board, unless it lets me take some chip off and install it as I just described...will again be too big and much overkill.

I reckon forget the coded switch.
It's the timer that will do the decoding (as per normal practice (for single-users)).

Maybe consider a digital up/down rotary instead (1+3 wire) so you don't need 1+12 inputs (or 1+4 bits) etc.

I believe this is going to call for a programmable microcontroller I can feed input from a switch and output timed pulses...but what chip, how to program, who knows!!!?

Well you could go with Arduino, they're cheap, and if you know C, you know how to program one. They're fairly easy

That was gonna be my recommendation.
Cheap, and with common open source information.

But I prefer uPCs over PICs anyhow....

(And I still prefer assembler LOL!)

But a dev board is gonna be too big. I need, literally, like a 555 chip thats not analog but programmable.

Fine.
Build your own PIC (8 pin)
Or use a Stamp uPC.

There are digital chips that can count down from a binary value. But then you have the problem of providing the binary value....
You can use ordinary rotary switches with enough diodes - but do you really want that?
Hence a PIC to do the binary, in which case it may as well do the timing - ie, the lot.

So, I can have a rotary switch, hexadecimal, which feeds values to a PIC and the PIC then pulses for a set period, sending power to another circuit for that period.

Dont suppose youve got a direction I could be looking for parts and a programmer?

The resistor bank with a ordinary switch has been tried, and while I am currently working on it to get it small and into the compact space where this goes, I wanted something less analog.