Dimmer instead of variac?

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  • zx81
    Senior Member
    • Mar 2014
    • 118
    • UK

    #1

    Dimmer instead of variac?

    Is it possible to use a triac based dimmer box in place of a proper variac to use for trouble shooting electronics. Can a dimmer be used to supply variable AC power to devices ?

    The dimmers I have are rated up to 2kw and I use them to dim tungsten lights for video work.
  • stj
    Great Sage 齊天大聖
    • Dec 2009
    • 30979
    • Albion

    #2
    Re: Dimmer instead of variac?

    no.
    a variac is a high current variable resistor that reduces the voltage.
    triac based dimmers mess with the ac waveform to create a pwm based output - they can damage electronic equipment by stressing the primary capacitor(s)

    Comment

    • zx81
      Senior Member
      • Mar 2014
      • 118
      • UK

      #3
      Re: Dimmer instead of variac?

      Thanks for that stj.

      I will search evilbay for a variac

      Comment

      • stj
        Great Sage 齊天大聖
        • Dec 2009
        • 30979
        • Albion

        #4
        Re: Dimmer instead of variac?

        good luck on the postage - heavy bastards those things!
        you should check carboot sales & that type of thing.

        Comment

        • zx81
          Senior Member
          • Mar 2014
          • 118
          • UK

          #5
          Re: Dimmer instead of variac?

          What kind of power rating should I be looking at for a variac. Would 8amps be enough ?

          Comment

          • zx81
            Senior Member
            • Mar 2014
            • 118
            • UK

            #6
            Re: Dimmer instead of variac?

            Would this do the trick ?

            http://www.ebay.co.uk/itm/Carroll-Me...item3cf521f833

            Comment

            • stj
              Great Sage 齊天大聖
              • Dec 2009
              • 30979
              • Albion

              #7
              Re: Dimmer instead of variac?

              how should i know, you never said what it was for!

              Comment

              • zx81
                Senior Member
                • Mar 2014
                • 118
                • UK

                #8
                Re: Dimmer instead of variac?

                Fault finding mainly TV's LCD, Plasmas, SMPS etc.

                Comment

                • zx81
                  Senior Member
                  • Mar 2014
                  • 118
                  • UK

                  #9
                  Re: Dimmer instead of variac?

                  Oh forgot to add most importantly blowing things up

                  Comment

                  • goontron
                    5000!
                    • Dec 2011
                    • 4108
                    • US

                    #10
                    Re: Dimmer instead of variac?

                    Originally posted by zx81
                    Oh forgot to add most importantly blowing things up
                    15 amp if you're going to do that...
                    Things I've fixed: anything from semis to crappy Chinese $2 radios, and now an IoT Dildo....

                    "Dude, this is Wyoming, i hopped on and sent 'er. No fucking around." -- Me

                    Excuse me while i do something dangerous


                    You must have a sad, sad boring life if you hate on people harmlessly enjoying life with an animal costume.

                    Sometimes you need to break shit to fix it.... Thats why my lawnmower doesn't have a deadman switch or engine brake anymore

                    Follow the white rabbit.

                    Comment

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