Using capacitors with "manual PWM" switching and walkmans

cburn · Joined: Feb 22, 2015 Posts: 8 Location: Earth

Hi,

I am controlling walkmans by rapidly mechanically connecting/disconnecting power (3v) in the speed range from milliseconds to seconds. I am pleased with how it works, but I would like to have the power stay on a bit longer than the actual connection is there.

So I am trying to lengthen the on state with capacitors. I am not sure on how to set this up for this purpose. I have successfully used RC debouncing with Arduinos, and I but I would like to try it in this scenario.

How should I wire the circuit? I figure I need roughly the same components as in an RC debounce circuit (2 resistors, 1 capacitor, 1 diode).

The project is by intent very primitive so I will avoid advanced solutions.

I am really thankful for help!

Cheers.

PHOBoS · Posted: Thu Sep 17, 2020 2:55 pm Post subject:

what are you using to turn it on/off as it might be easy to adjust the pulsewidth.
Otherwise a diode followed by capacitor could do the trick but because of the power consumption you might need a fairly big cap.
Downside with a big cap is that it takes longer to charge which can result in a ramping up and down of the speed.

cburn · Joined: Feb 22, 2015 Posts: 8 Location: Earth

Hi, thanks. I am using coil springs that bounce on and off metal plates, so I can not really change these.
I was seeing in my experiments that a big cap seemed to be necessary. But what if I would use 5 or 9 volts and use a resistor to get it down to 3v?