Hi. I'm trying to find the simplest way to drive a bi-color LED using one color (green) when 12 volts sensed, and red when 0 volts sensed. I understand the resistor values I need to put on each leg to limit the current ( (12-.7)/20ma ), but not sure the simplest way to do this. Essentially I'm going to have a series of indicators in a room that indicate if a door/window is open or if something is left on. I know how to drive the 12 volt indicator from the source using microswitches or relays, but my question is at the LED indicator side of things. I'll have 12 volts if something is normal (green) and red if abnormal (0 volts). Given I may have up to 20 of these things, using relays to drive the LEDs would be way overkill.
Thanks in advance. I did search for this, and will keep searching.
Part number I'm using:
https://www.amazon.com/EDGELEC-Bi-Color-Resistors-Included-Emitting/dp/B077X91PLX
Only other similar search I found:
https://forum.allaboutcircuits.com/threads/small-bi-color-led-circuit.5956/
Thanks in advance. I did search for this, and will keep searching.
Part number I'm using:
https://www.amazon.com/EDGELEC-Bi-Color-Resistors-Included-Emitting/dp/B077X91PLX
Only other similar search I found:
https://forum.allaboutcircuits.com/threads/small-bi-color-led-circuit.5956/