Author Topic: Electrolytic Capacitors  (Read 460 times)

Offline kubusi

Electrolytic Capacitors
« on: December 02, 2016, 08:18:16 AM »
I have used a good source of higher voltage electrolytic capacitors when building or repairing valve equipment, look no further than your scrapped switchmode power supplies from PC's. Voltage ratings are generally from 200 volts upwards and capacities in the hundreds of microfarads. Connect 2 or more in series to obtain the total voltage rating needed not forgetting equalising resistors across each one. Some power supplies I have found do have resistors across the capacitors and others do not which is taking a bit of a chance as you can risk having unequal voltages across each capacitor. In some cases I have removed the guts out of defective aluminum chassis mounted caps. and fitted these smaller items into the casing and epoxied it together again
There is also another free source of electrolytic caps where the ripple current is fairly low in the
range of capacities of 2.2 to 6.8 mfd at a voltage rating of 400 to 450 volts, all very small physical
size which I have made good use of a number of times, look no further than your failed energy
saver light bulbs and as a bonus you will find 1 amp rectifiers such as the 1N4007 or equivalent.
You will also come across a few other non elecrolytic caps. rated at 400 or 1000 volts depending on the circuit used. Looking for nonpolarised high voltage items, in every scrapped microwave oven you will find one.
Finally I have found on checking these salvaged capacitors on a bridge the capacities are always very close to the marked capacity,  not like in the past years where the actual tolerance was in the range of  +100% to -50%.
FIRST LAW OF VALVE AMPLIFIERS
Hot glass looks exactly the same as cold glass.