How to find the correct transformer for a power supply project? Answered
I can find the correct part online from the schematic I am reading for every one but the transformer. The symbol for it states that it is a metal core transformer that one side (2 leads) connects to an outlet plug (117VAC) but the other side has has 3 leads labeled 0V, 24V, and 30V. There is a switch that goes between the 30V and 24V leads to allow you to switch between 15-30V or 0-15V, then connects to a diode bridge in which the unregulated DC heads to the regulator. I can see that it's a tapped transformer, but how do I find such a part at, say, Jameco or DigiKey? What are the search parameters? I find nothing if I search for "117VAC (or 120VAC) to 30V transformer". If I want to find a certain diode, capacitor, or transistor, it's a snap, but I have to back away from projects that require transformers because I'm not sure how to find exactly what I need even if I have a schematic. Any help would be greatly appreciated. Also, if it helps, I got the schematic from page 472 of volume 2 of the Encyclopedia of Electronic Circuits (Rudolph F. Graf).