How did the real WW2 torpedoes get programmed?

[jscharpf]

Maybe a silly question, but as I set my TDC with AOB, speed, distance, and get ready to open the tubes and hit the fire button, I was wondering how this eventually gets translated to the actual torpedo.

Is there an electrical circuit inside the torpedo tube that sets the torpedo up according to the TDC or is an operator told "hey set torpedo 1 to xxx"..?

What is inside the torpedo to make it run correctly and how is this set?

Of course this is only a question for WW2 era torpedoes, because I'm sure modern systems are much different.

Any good resources regarding this?

Jeff