Help - Isolation transformer

Discussion in 'General Electronics Chat' started by cumesoftware, May 5, 2007.

  1. cumesoftware

    Thread Starter Senior Member

    Apr 27, 2007
    1,330
    10
    Well, I need an isolation transformer with the following specifications:

    Primary:
    220V AC

    Secondaries (isolated from each other, not tapped):
    230V AC (could be 460V AC, but I think those don't exist, so I will use a full wave voltage doubler instead)
    6.3V AC (300mA minimum, for the heater)

    This transformer is for an oscilloscope CRT. I think if I got a 1:1 isolation transformer, I would be glad (I can add another transformer to supply 6V to the heater). The objective here is to have 600V DC (230VAC x 2 x 1.414VDC/VAC = 650VDC).

    Could anyone recommend a trafo model or a manufacturer?
     
  2. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
  3. lightingman

    Senior Member

    Apr 19, 2007
    374
    22
    Yes I am sure I have some..I will look on Monday..If I have one, you would be welcome to it..But where are you..Daniel.
     
  4. awright

    Well-Known Member

    Jul 5, 2006
    84
    7
    If you use a separate transformer for the CRT filament, be sure that it is insulated for the DC voltage to ground that it will be subjected to. An ordinary off-the-shelf filament transformer will not stand up to the DC voltage.

    awright
     
  5. cumesoftware

    Thread Starter Senior Member

    Apr 27, 2007
    1,330
    10
    Well, in my situation, isolation will be really needed. But I prefer a "plate and filament" transformer (or a "valve power" transformer), since those are more adequate. I will use a 500V AC secondary and forget about the voltage doubler.
    I need a transformer suitable for 230V AC (I think I cannot use one for 220V AC, and a trafo for 240V AC would be ineficient).
     
Loading...