On Thu, Sep 4, 2014, at 11:15 AM, Gene Heskett wrote:
> pieces of wood to hold a pair of huge 15k uf, 60 volt Sangamo capacitors > in a power supply I'm building for the lathe motor > I don't trust the 140 > volt surge ratings of the smaller 100 volt caps > With this > transformer, those 100 volt caps have a no signal voltage of 113 volts. > I'll put 7 watt night light lamps > across them for charge equality and power down bleeders. Be very carefull using light bulbs as balancing resistors. They have a resistance vs temperature curve that can bite you. You can get in a situation where one bulb has a bit less voltage across it than the other. The one with less voltage dissipates less power, it cools down and the other one heats up. Its resistance drops and the other one increased. That results in even less voltage across the cool bulb, and more across the hot bulb. The cool one gets even cooler. Depending on the exact characteristics of the bulbs and the total applied voltage, you can wind up with a 2:1 or bigger difference in voltage. I would dig in my scrap boxes for real resistors if I was you. -- John Kasunich [email protected] ------------------------------------------------------------------------------ Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
