Enginuitor Posted July 25, 2004 Report Share Posted July 25, 2004 I recently stopped by HSC (a local surplus place) and found a big old lab power supply that came from the Lockheed Martin labs in Sacramento. Standard 4-knob controls (coarse/fine on both voltage and current), analog meters. 0-40 VDC @ 0-10 amps! Only problem was, it didn't work. So I managed to talk them down to $25 (from the initial $50 price tag), and took it home to the bench.Lucky for me, this thing is 80% discretes, plus some common transistors and two very standard IC's. 100% replacable!There were three components inside which showed heat stress: a 12V zener diode, a 1.5k resistor, and this strange electrolytic capacitor with 4 leads. I went back to HSC and bought higher-wattage replacements for the resistor and the zener, but the capacitor stumped me. They didn't have a single capacitor like it. It's a metal-can type, with glossy plastic ends and transparent shrinkwrap over it. There are two leads coming out of each end; each end has a + and - lead. It's marked "CDE" "UFT 570-75", rated at 570MFD, 75VDC, and 105.oC. There is obvious heat stress around the points where the leads enter the body. and the ends are bulged slightly. Here's where I'm stumped... I brought the cap to one of the guys who ran the store, and he said it was probably two caps in one can, as was a popular strategy a while back. However, when I got back home, both my multimeters and an old-fashioned lightbulb continuity tester indicated that the leads on each end were continuous with each other (meter read 0.00), making it appear to be a single radial cap with the leads going in one end and out the other, perhaps for better power/heat handling. Or perhaps it truly was one of those old-fashioned duplex capacitors, and somehow it has failed in a way that by some twist of fate has caused both ends to become connected?I would appreciate any help identifying this cap, and designing a suitable setup to take its place. As a last resort, I might just slice this baby open over the acid tub, and see what it looks like inside.Thanks in advance. Quote Link to comment Share on other sites More sharing options...
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