Hi all,

I am looking for a simple circuit to control a 12V piezo buzzer(max. current 30mA) using 2x +positive feeds and 1 negative/ground.
The negative will always be connected, I need it to be "ON when only 1 active is supplied" and "OFF when 2 are supplied simultaneously" without using a relay
I was thinking of using switching transistors but can't work out a simple solution, any help would be appreciated

 

https://electrosome.com/xor-xnor-logic-function-diode-bridge-transistor/

 

Use Exclusive Or gate...

 

Fantastic, such a simple cheap method! Thank you