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previous: confused What is the best and safest way to ... -- 11/7/1997 2:25 PM

Re: charging caps

11/9/1997 7:08 PM
Tony Taliaferro	Re: charging caps You must be talking about the forming the dielectric in the electrolytic caps in the power supply. This is done by bringing up the amp plug voltage in steps slowly (a few volts per hour until line voltage is achieved) with a variac to insure that the dielectric or electrolyte material inside the cap has or is not crystallized due to long periods of non-use or storage. This can be done outside the amp circuitry by putting the cap in series with a high value resistance (several megohms) and attached to the full rated DC voltage for a couple of days. The high value resistor prevents an over current condition and the voltage across the cap should eventually get close in value to the applied voltage if the cap is good. Another way to reform an old cap is to place it in a 120 to 140 degree oven for a few hours (kids don't do this in your home oven)!

11/9/1997 7:08 PM

Tony Taliaferro

Re: charging caps

You must be talking about the forming the dielectric in the electrolytic caps in the power supply. This is done by bringing up the amp plug voltage in steps slowly (a few volts per hour until line voltage is achieved) with a variac to insure that the dielectric or electrolyte material inside the cap has or is not crystallized due to long periods of non-use or storage. This can be done outside the amp circuitry by putting the cap in series with a high value resistance (several megohms) and attached to the full rated DC voltage for a couple of days. The high value resistor prevents an over current condition and the voltage across the cap should eventually get close in value to the applied voltage if the cap is good. Another way to reform an old cap is to place it in a 120 to 140 degree oven for a few hours (kids don't do this in your home oven)!