Having some trouble with transistor logic.
I have an existing circuit with a 3.3V rail and signal rail that is pulled to 0V when asserted, i.e. active low. I ultimately need to control four 12V LED clusters, which draw 125mA each. From hereon I shall refer to 'four 12V LED clusters' as a single LED for simplicity. I can use PNP transistor to power a 12V LED, However I would like a second LED that is the inverse of the first.
I tried to add NPN, with the base on the signal and a pullup resistor on the base to the 3.3v rail but this causes the PNP to be always on as current can flow from the PNP base through the NPN base to the 0V rail. A diode would stop the flow for the NPN.
After reading CharlieHanson comment got further on but I need the LEDs to be ON or OFF not reduced.
EDIT: To reiterate, Switch 1 does not exist. It's an output of another board that is either high impedence (actually disconnected) or 0V.