Sometime back we (me and several Pinside members) built a power supply for testing MPUs.
Inside the box are two separate power supplies – one for 12 and 5 volts and one for 24 volts.
Each section has its own transformer, wiring, fuse, and on/off switch. I only use the 24 volt section for checking zero crossing and seldom use it. Normally when I use the power supply I connect ground to TP4, 5 volts to TP5, and 12 volts to TP2. When I use the 24 volt section I also connect ground to TP4, and 24 volts to TP3. Therefore I have two test leads connected to TP4.
What would happen if I connect both ground wires together at the power supply?
Would the ground wire have any effect when using only the 5 & 12 volt section?
I may win the dumbest question award but I don’t want to harm my power supply.