I'm building a power control circuit for a Raspberry Pi that uses a CD4043 latch, and I think I should be resisting static/noise on the inputs (especially the reset input) to prevent accidental power-offs, but I also need to be able to send it deliberate power-off commands. I can't work out how to create a simple circuit using caps/inductors/chokes/resistors/transistors. Please assist.
The concern came because while the circuit does function it's intermittent. I may just have a bad solder joint but I realized that even if that's the case I should filter out noise.
Requirements:
* Momentary button to turn on the Pi
* Noise cannot accidentally turn on or off the Pi; need at least 100ms of press time to activate the latch set input
* Must be able to power the Pi on either battery or 5V USB wall power, which would not be grounded
I'm testing various configurations in
Falstad. If I use a choke on the input, applying the switch gives an immediate 5V to the latch. If I put a cap and resistor to ground it still gives an immediate 5V. So I'm lost. Maybe I need some kind of FET/cap/resistor combo? Please assist.