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On 15 Jun 2004 at 10:05, Mark @ Mo-Sys wrote: > Jim, if its not a trade secret, what do you do to them? I have just fitted a > new (old) one and would like to do anything that would help it live a long > life. I looked inside and it has a little pcb with a transistor and a few > other bits, and one of the ones I have had what looks like an ancient diode > underneath where the other has just a wire. Are you fitting flyback diodes > accross the coils? Yes, I solder a small 3A diode on the underside where it ends up being placed across the field winding as a freewheeling diode. This keeps there from ever being any inductive flyback voltage from developing across the internal points when they open, even if the resistor there goes open (which it ALWAYS eventually does.) The only real trick is knowing where to attach the diode, and in choosing an appropriate diode. Of course if you get the diode in backwards nothing will work, and I think the diode and VR will be instantly destroyed. ;-p -- Jim Adney jadney@vwtype3.org Madison, WI 53711-3054 USA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org