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Hi Everyone AC-DC Power Supply ?

  1. Nov 5, 2006 #1
    Hello, I'm new here and I apologize for my first post being a design question. I'm a 20 year old junior Electrical Engineering student from the University of Akron.

    I need some help with a design that I can't get working for the life of me!!

    If you know pSpice Schematics, or OrCAD Capture, then you might be able to help me out.

    I have to design and simulate a linear regulated power supply that takes 120V RMS @ 60Hz and outputs 4.7V DC. It has to be capable of supplying a load current up to 30mA with an output ripple of no more than .5V and it has to use a half wave rectifier.

    Now, my idea was to use an AC voltage source into a linear transformer (turns ration to be decided by experimentation), then run the transformer output into the half wave low-pass rectifier (which would just be a diode and a shunt capacitor), the voltage output of that would run into a voltage regulator or zener diode for smoothing.

    I've tried this in Schematics and I was unable to get anything resembling a working circuit. I also tried it in Capture but I'm no good with Capture cause we've NEVER used it and alluva sudden, this teacher wants us to use it.

    Can anyone give me any helpful advice, circuit schematics, or could even show me what I should be doing in pSpice? I've searched the internet for working schematics that I could easily input to pSpice but I was unable to find anything.

    Thanks for the help.
  2. jcsd
  3. Nov 5, 2006 #2
    anyone with any insight?
  4. Nov 5, 2006 #3


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    I'm not sure what specific question you're trying to ask -- are you just unfamiliar with how to use PSpice?

    - Warren
  5. Nov 5, 2006 #4


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    Have you tried Googling? I'm sure there are many, many web sites that address the very simple power supply you describe, including the transformer, rectifier, and smoothing (and there's more than one way to skin that cat, especially if your prof doesn't specify price limits on your components). I don't use any circuit modeling software, and can't help you with that aspect - I repair tube-type guitar amps as a hobby (once as a part-time business) and troubleshoot with schematics and a DMM, so I'm kinda stone-ages about EE. Good luck.
  6. Nov 5, 2006 #5
    I've used Pspice Schematics for about a year or so, and have NO experience with OrCAD capture, but it doesnt seem to be working for me with this project. It's the first time we've ever had to do anything with Diodes in pSpice. So that's part of the frustration, but i'm also having difficulty selecting components and the values to get the particular output that is desired.
  7. Nov 5, 2006 #6
    here is my thought at a design, but i have no idea if i'm thinking correctly or what to put as values for my components...it also wants values for the diodes and I don't quite know what should go there...and i'm also getting an error saying "Voltage source and/or inductor loop involving V_V1"...

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