I have a bi color led red/blue with a common cathode. the led will be regularly blinking with blue from a 12vdc pulsing circuit. when a sensor I have detects motion it has a wire and will send out a negative signal to the bi color led to switch it from blue to red as long as this negative signal is present. I figured I could use a couple of transistors to get this done but I'm not sure where to start. I know I will need to take this negative signal and convert it to positive for the positive side of the red led. I have 12vdc and ground as a power source.
on a side question how can I use a transistor in place of a mechanical relay that will switch with a ground command?
thanks to all that respond.
on a side question how can I use a transistor in place of a mechanical relay that will switch with a ground command?
thanks to all that respond.