Original poster: Bert Hickman <bert.hickman@xxxxxxxxxx> Tesla list wrote:
Original poster: "David Rieben" <drieben@xxxxxxxxxxxxxxx> Hi all, I ran across this item on ebay and was wondering if anyone could offer a good description of it :<http://cgi.ebay.com/KIRKHOF-F4490W625W-WELDER-TRANSFORMER_W0QQitemZ200099067349QQihZ010QQcategoryZ11774QQrdZ1QQcmdZViewItem>http://cgi.ebay.com/KIRKHOF-F4490W625W-WELDER-TRANSFORMER_W0QQitemZ200099067349QQihZ010QQcategoryZ11774QQrdZ1QQcmdZViewItemI'm assuming that it is some type of industrial welder transformer, as the description states. It is rated at 230 volts @ 69 amps and I'm thinking that this would make for one heck of a pig coil ballast. However, there is also wording on the label about motor rpms and ball bearings? So is this a transformer or a motor? It would nice if this 210 lb. chunk could be used as a pig ballast as this seller is only located about 50 miles from me, which means that I could go and pick it up instead of having to pay those expensive freight charges. Thanks in advance for your comments, David
Hi David,I love the massive lugs coming out of that beast! It looks like a spot welding transformer. It also has a current adjustment that apparently selects discrete transformer taps to adjust output voltage (and current). The output open circuit voltage of a spot welding transformer is typically no more than 3-5 volts, and the "loaded" voltage across the joint during welding is typically only a volt or so at thousands or many tens of thousands of amperes. Like arc welding transformers, spot welding transformers are often constructed with built-in leakage reactance so that they behave sort of like a current source during welding, so it may indeed function as a high power ballast for a TC. Less expensive/homemade spot welders simply rely on voltage taps and combined circuit resistance of the secondary winding, cabling, and electrodes to provide a level of current control.
However, it also looks like the single picture in the auction that shows a comparatively clean spec sheet for 230/460 volts and 69/34.5 amps is actually for a 30 HP motor and NOT this welding transformer. The bottom line shows that it is from Fort Wayne, Indiana while this welding transformer was made in Grand Rapids, MI. Sounds like a question for the seller...
BTW, here's a patent assigned to the Kirkhof Manufacturing Corporation that may shed some light on the internal construction of this transformer. The company is now Kirkhof-Goodrich, Inc., a small division of Mark IV industries.
http://cgi.ebay.com/KIRKHOF-F4490W625W-WELDER-TRANSFORMER_W0QQitemZ200099067349QQihZ010QQcategoryZ11774QQrdZ1QQcmdZViewItem Nice find (or a very nice yacht anchor)! Bert -- *************************************************** We specialize in UNIQUE items! Coins shrunk by huge magnetic fields, Lichtenberg Figures (our "Captured Lightning") and out of print technical Books. Visit Stoneridge Engineering at http://www.teslamania.com ***************************************************