Oil burner ignition unit?

Discussion in 'General Electronics Chat' started by Classictrial, Jul 26, 2012.

  1. Classictrial

    Thread Starter Member

    Aug 23, 2010
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    Would it be feasible to use the ignition unit from an oil burning boiler, to generate the HF current required on a TIG welding set?

    Some people seem to be using these to produce the HF on arc welding sets adapted to DC TIG operation, but I wonder whether or not this is likely to work properly and is safe?
     
  2. gerty

    AAC Fanatic!

    Aug 30, 2007
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    The ignition units that I'm famalliar with are just step up transformers that raise the voltage to 10,000 volts, the frequency is still 60 cycles per second.
     
  3. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    OBITs (Oil Burner Ignition Transformers) generally run at 50/60 hertz, which is nowhere near high frequency. Also, I'm pretty sure TIG welders use low voltage, high current. OBITs provide high voltage at low current. I don't believe they would work for that purpose.
     
  4. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    Tig only needs the high volt, low current for the "high freq". Its just used intermittently to start the arc. Ionizes the gap to start the arc, without it you scratch start, and can contaminate the tungsten electrode. Don't really know why they call it "high frequency" though, since most aren't. Suppose it sounds 'safer' than high voltage.:)
     
    PackratKing and DerStrom8 like this.
  5. Classictrial

    Thread Starter Member

    Aug 23, 2010
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    Thanks for your replies. I get the feeling that the OBIT would probably work on a TIG welder, but doubtful whether it would be safe or not?

    Its probably a better idea to buy the factory replacement part, but its for an old machine, and not being able to check whether the ignition unit on it is working or not, means taking a chance on the ignition unit being the cause of the actual problem.
     
  6. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    Like in your original thread, you need to check the spark gaps. I know you said there isn't any, but some times there under a cover. The spark gaps are what creates the "high freq." from the high voltage. Have you checked the tank caps?
     
  7. Classictrial

    Thread Starter Member

    Aug 23, 2010
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    The HF parts on this machine consist of a control board, which is connected to a solid state HF generator about 2 inches square, which is connected to an inductor coil, which connects to the torch power lead. There is no noise from the HF generator when the HF is working, and I would guess that all the parts inside are likely to be potted. I can try to take the HF generator apart, but as its completely silent when HF is working, not sure if there are any parts inside it would be possible to service or check? Worth a try though, and I will take it off the machine today and have a look.
     
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