I have a built a little relay circuit to control a light from the inputs of a motor controller board. When the motor runs I want the light to turn on, when it stops I want the light to stay on and when the motor reverses and stops in a "home" position I want the light to turn off. This is a 12V DC system and my motor enable and motor reverse are negative inputs.
I have a relay that latches (light on) when the motor is enabled and the reverse enable breaks the latch (light off). It works pretty well but about 1 in 20 times the latch will not break when the motor reverses. If I could extend the reverse enable for a short time this would fix the issue. If it was triggered by a positive input I would think that I could just add a capacitor as a buffer to extend the time. Not sure how to do this with a negative input. Any ideas?
Thanks.