Categories
Ask Engineering

Diode OR or transistor OR circuit?

I need a circuit that converts a 3.3V signal into a 24V signal. But I also need to be able to activate the 24V signal using a PCB switch. I can do it in two ways, using a diode OR or using a transistor OR, which one is better? They both look ok in the simulation.

Diode OR:

Transistor OR:

EDIT:

After @BruceAbbott comment I’m adding a third simpler option, just short circuit the first transistor Q1:

V(n002) is the control voltage of the SWCTRL switch.

Leave a Reply

Your email address will not be published. Required fields are marked *