Welder Ballast..?
RSS | Subscribe | Contact Us | Advertise | About Us
Results 1 to 6 of 6
  1. #1
    Join Date
    Nov 2005
    Location
    Gillette, Wy
    Posts
    591

    Welder Ballast..?

    While looking at several schematics for welder controls... would it be possible to build a primary ballast? My Hobart has a saturable core reactor, and that gave me the idea... take a MOT ( or two ) either rewind them with a heavier winding or use as it. DC bias the 'secondary' to allow more current thru the 'primary'. Would such a critter work or am I barking up the wrong tree..? Thanks
    Robert

  2. #2
    Join Date
    Jun 2005
    Location
    delaware
    Posts
    155
    man, I don't even know what tree you are talking about!

  3. #3
    Join Date
    Mar 2005
    Location
    Carrollton GA
    Posts
    2,329
    When you say "ballast", is that the same as a "transformer"? There are often many words that describe the same thing, so I just thought I'd ask. You probably need to define your other terms so you get the best response possible.
    Smithboy...
    if it ain't broke, you ain't tryin'.

  4. #4
    Join Date
    Nov 2005
    Location
    Gillette, Wy
    Posts
    591
    I got the idea from a local neon shop, where he uses a variable inductance choke to control the bombarder transformer. Thinking about how my welder ( and several others ) control their output currents, i wondered if the same technology couldn't be applied to the input. By ballast, i mean choke, in it's simplest form. Instead of an SCR control for the input, have an inductive control.

    I had an idea that if one used a saturable core ballast ( similiar to the output control of a dialarc or a tr250 ) im sure there are others, but those two im familiar with.

  5. #5
    Join Date
    Nov 2005
    Location
    Santa Fe, NM
    Posts
    1,708
    This sounds like it could be an interesting idea, but I'm struggling to figure out what the heck you're trying to do. What would this device do for you? What would this thing control? How would it affect the arc, and what welding process are you talking about?

    You mention inductance. I know of an application with an early pulsed MIG power supply, where the designer put an inductor into the final weld circuit to limit the rate and extent of very high current spikes during short circuit events. This had the effect of slowing down current fluctuations, reducing spatter, and smoothing out the arc. The prototype inductor was made in 2 minutes by simply coiling the work cable (-) around a chunk of steel.

  6. #6
    Join Date
    Nov 2005
    Location
    Gillette, Wy
    Posts
    591
    Im trying to control a Hobart TR250 ac/dc machine, primarily used as a TIG supply. There are times on it's lowest setting (around 35 amp), it burns right thru what im trying to weld, ( sheet metal, copper tubing...). I've seen some very interesting SCR control circuits that seem to do the same thing; however, my electronics knowledge for controlling scr's is a bit lacking. ( that and the scr's i have are only 200 volt rated ) I was thinking of replacing the rectifer diodes in the welder with the SCR's and doing it that route, but back to the lack of experience I go.

    After carefully studying the schematic diagram for a couple of transformer welders ( dialarc and my tr250), I came up with the idea of using the control reactor ( or magnetic amplifier as miller calls it) to control the input to the unit ( like the scr controls, but using a variable inductor instead ).

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
RSS | Home | Penton Media | Contact Us | Subscribe | For Advertisers | Terms of Use | Privacy Statement