Is this power supply regulated?

Discussion in 'General Electronics Chat' started by campeck, Aug 14, 2010.

  1. campeck

    Thread Starter Active Member

    Sep 5, 2009
    I need 5v and 2.2A out of this plug in PSU. It's rated at 5v output and 3A.
    P/N 281855-001

    I need it regulated but can't find out if this one is. I can't use a regulator IC because of the voltage drop and the only other PSU I have is 26V which will heat the *** up out of the IC.

    Last edited by a moderator: Aug 15, 2010
  2. Jaguarjoe

    Active Member

    Apr 7, 2010
    Measure the no load output. Should be 5.x volts, with no AC ripple. If its DC output is much higher than 5 volts its probably an unregulated supply.
    Measure the output again, this time with a load on it-maybe a 5 ohm resistance for 1 amp load. Should be 5.x again (or real close to it) once again with no AC ripple.
    Try bigger loads up to your 2.2 amps and look for similar results.
    If the DC output sags as the load goes up and the AC ripple grows, its an unregulated supply.
    PackratKing and kingdano like this.
  3. marshallf3

    Well-Known Member

    Jul 26, 2010
    Exactly, those unregulated 5V wall supplies usually put out around 7.5V no load, even higher if they're lower amperage suppies as the secondary winding has a higher amount of internal resistance they depend on to drop the voltage.
  4. Jaguarjoe

    Active Member

    Apr 7, 2010
    In case yours isn't regulated, All Electronics has a 5 volt 3.75 amp switcher wall wart for only $4.75. That's pretty cheap.

    Well, scratch that, they're out of them :(
    Last edited: Aug 15, 2010