Power Supply Project Begginer help

Discussion in 'The Projects Forum' started by raynmanSD, Mar 5, 2011.

  1. raynmanSD

    Thread Starter New Member

    Mar 5, 2011
    2
    0
    I am building a power supply according to G. Randy Slones Guide to electronics. I just got through connecting the bridge rectifier and I am getting correct readings on measuring DC voltage (+24volts and -24volts), but my AC volt readings measure +54 volts and 0 volts not +12 volts AC for each reading as the author expects.

    Attached is the schematic. I am taking the readings with black DVM lead attached to the circuit common and the red lead connected to the negative output of the BR for reading 1 (0 volts ac), and the positive output for reading 2 (+54 volts ac).

    This is the first time my readings did not match the authors and I am stumped on what to do.

    Thanks for any help.
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    You don't actually have the black DVM lead attached to the circuit common ground; you have it connected to one of the "ends" of the secondary winding.
     
  3. raynmanSD

    Thread Starter New Member

    Mar 5, 2011
    2
    0
    Sorry I don't no why I added Ground what I meant to say was the circuit common connection (which I took to mean the connection between the 2 transformers via there secondary leads.)
     
  4. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    3,779
    932
    measure the AC at the output leads of the transformer(secondary) or at the input of the rectifier. The ground is AFTER the diode so using it will NOT show a true AC voltage

    using the ground will only show you DC components of the AC signal
     
Loading...