ATX 3.3 vdc rail, how to drop to 1.5 vdc for electroplating?

Discussion in 'General Electronics Chat' started by sdowney717, Apr 20, 2015.

  1. sdowney717

    Thread Starter Member

    Jul 18, 2012
    I was experimenting with electroplating copper to steel.
    I first tried a 6vdc battery charger, which was too high volts.
    Then I tried an ATX power supply using the orange 3.5 v wire, and it is also a little too high, I get a lot of hydrogen gassing off of the steel.

    I have a lot of 5 watt 100 ohm resistors. Could they be used as a voltage divider?
  2. cornishlad


    Jul 31, 2013
    Probably not..what current does the process draw ? Is the current fixed or does it vary ?
    Starting with simple, if the current is fixed, a small series resistance in series with the 3.5v supply should do it. or some series silicon diodes - allow about .6 Volt drop for each one introduced
  3. Dodgydave

    Distinguished Member

    Jun 22, 2012
    some Atx 3.3v rails use a tl431 regulator on the 5 v rail,with a fet, otherwise they have straight outputs on the pulse transformer, i modified an atx to variable and the 3.3v rail went down to 1.8 to 6.5v,
    Last edited: Apr 20, 2015