Cap reformation question

Hi It is an interesting article but I suggest that the leakage currents may be over stated. 1,000 ma at 500 Volts is 500 Watts. This is way too much for a capacitor. Even 1 ma at 500 volts is quite a bit more than most capacitors can handle for any length of time at 500 Volts. I would suggest that the translation from the original article may have replaces the micro symbol with a m instead of a u as is normally done. Things to consider are that there are two factors when reforming. There is the production of gases that is directly related to the current flow and then there is the power dissipated. This is voltage times current. Both must be considered. A 500 volt capacitor should never have more than 1 ma of current flow and should most likely be in the 100 ua range for much of the reforming. Low voltage capacitors can handle more power but become limited by the gases produced and not the power. 10 ma for a good sized can is about max. Smaller cans should have less current. A small 10 uF 30V cap shouldn't have more than 25 to 50 ua at most. It has been mentioned that one can use current limited supplies. I've not seen ay that would limit the current to a fine enough adjustment to be correct for reforming. A resistor is best. Always start with a lower voltage even if you have a resistor. The oxide coating in the capacitor is not evenly eroded. It has a number of locations that may be thinner. These need to be brought up to the level of the rest without over heating them locally. To determine when to bring the voltage up, watch the voltage drop across the limiting resistor. I recommend starting with a voltage of about 1/10 the rating and measuring the voltage. Each time the voltage is increased, never let the current go more than was seen at the beginning. This can be observed by watching the voltage drop on the resistor. Never start with more than 1/2 the rated voltage, regardless of the current limiting resistor. Always finish by bring the capacitor to the full operating voltage. One doesn't need to bring it to the rated value. Most of the methods mentioned here for current limiting protect the rest of the supply but not the capacitor. A lamp on the input leads will not do much to limit current at the levels needed to keep excess gas from building in the capacitor. Those that have had success have been luck rather than having a good procedure. Remember, excess gas will not show failure until some later date. The capacitor will seem to be OK but dry up over time because of a ruptured seal. Using a lamp on the input to a variac may not be too useful. The variac waste quite a bit of power. In order to get the variac to a useful operating level, the current limiting will be way beyond what is useful in protecting a capacitor while reforming. A series resistor at the capacitor is the only method I know that is truly safe for the capacitor! Dwight.