I'm trying to design a circuit that will switch between two power sources using commands from a Raspberry Pi. Both power sources are 12 V and the desired output voltage is 12 V and max. 2 A.
How I want the circuit to work is as follows:
If I want source 1 to supply voltage, GPIO1 should send a HIGH signal.
If I want source 2 to suppy voltage, GPIO2 should send a HIGH signal.
One source or the other should supply voltage, or none at all. They should never be ON at the same time.
Question 1: Does this circuit achieve what I'm trying to design?
Question 2: In order to prevent a short circuit in case both GPIO1 and GPIO2 happen to turn on at the same time, would adding high-current diodes to the outputs of each transistor (Q1 and Q3) solve it? If yes, what type of diodes should I use to ensure that I get 12 V at the output voltage? Would they be connected in parallel or in series to the output of each transistor?