Hi.
Quote:
Originally Posted by Wilder Amplification
Instead of using the variac, another trick I know of to form caps is to install a 100K resistor between the positive side of the rectifier and the first filter cap, then monitor the voltage drop across this resistor with a DMM as the caps form. Once it's down to 5 volts or less, the caps are formed and you can then remove the resistor.
|
Thanks Jon, didn't think of that.
Fortunately I've always had a variac as I found an old 2KW "dimmer unit" back in the day when I was starting out. Just a largish 2KW variable resistor really
.
Been using that ever since for all "soft starts". Not ideal, but gets the job done.
Been using that for another application that You can probably guess as well, but as it's not recommended by anyone I'll leave it at that...
John, IMLE all the electrolytic caps that have not been used for a while will benefit from the "soft start" as the physics and chemistry is about the same regardless of the size.
The higher voltage ones obviously are the ones which we are concerned with, as those are the ones in the power supply and are the most expensive ones.
On a circuit, there's usually a "soft start" by design so those caps are less likely to suffer.
If there's no visible damage on an el-cap, virtually all can be revived/reformed. IMLE again.
Regards
Sam