Hi all,
I'm a first time poster here and I apologize if this has been asked before -- I searched but didn't see anything similar. I'm trying to get into some electronics design and thought a good first project would be a variable voltage power supply to power all of my projects. Hopefully I don't make myself look too dumb with this question
Problem
I am trying to follow the design at **broken link removed** since it has good descriptions and alternate parts lists, but I am running into a problem where my bridge rectifier keeps burning out. I have disconnected the entire circuit such that it is down to just the transformer, bridge rectifier, and C1, but the same problem happens.
Once I plug the circuit in, I hear a crackling noise coming from the rectifier. After about 5-10 seconds it gets extremely hot and releases the magic smoke. If I have a multimeter attached to the capacitor, I do read a steady voltage though I can't remember what the value is at the moment -- it seemed reasonable when I took the measurement.
Parts
-The transformer I am using is a 12.6V 3A one which I got at radioshack (
https://www.radioshack.com/product/index.jsp?productId=2102702).
-I have tried two different bridge rectifiers. The first was an NTE5312 rated at 100V 8A. The second was picked up at radio shack and is rated at 400V 8A
-C1 is a 1000uF 50V electrolytic capacitor.
Connections
I am using an old computer power supply cable to connect to the 120V AC to the transformer. The ground pins of the plug, rectifier (- pin), capacitor, and the center tap (black wire) of the transformer are all connected together. The two other pins of the plug are connected to the two AC inputs of the rectifier. The + output of the rectifier is connected to the + side of the capacitor. I have tried to illustrate this in the attached diagram.
Thanks in advance for any help on this.