Stoneridge Engineering Home |
jacobs ladder
Posted by mario occhipinti on 12/11/2003, 8:21 pm
|
Re: jacobs ladder
Posted by Bert Hickman on 12/11/2003, 9:40 pm, in reply to "jacobs ladder" Hello Mario, Hmm... the welder sounds like it may be the problem. In a ballasting application, you ideally want to use a simple AC stick welder such as a Lincoln AC-225S or similar. Internally, this type of welder uses a specially designed transformer that has an adjustable magnetic shunt which inserts a magnetic path in order to bypass part of the magnetic flux that would otherwise directly link the welder's primary and secondary windings. The transformer is designed to have considerably more "leakage" inductance than most other types of transformers. With the LV side of the welder short circuited, the welder looks like a simple, non-saturating inductor in series with the pig's LV winding. However, an AC/DC welder will have additional hardware that (at the very least) rectifies the output of the welding transformer. The additional circuitry in your welder may be creating some undesirable interactions - if these result in the welder's transformer going into partial saturation, then it will allow too much current flow, blowing the breaker. If the welder's output is switchable, try setting the output so that it supplies AC only. If that still doesn't do the trick, you may need to get a simple AC stick welder or make your own ballasting inductor. A couple of 500 foot rolls of #10 or #12 AWG THHN (leaving the wire on the rolls, no core) in series with the pig will make an acceptable "poor man's" ballast for short duty cycles. Hope this helps! Bert
|