Always good to discharge the supply cap. The discharge spark was louder than the camera pick up.br 150 Volts AC rectified to 200 Volts DC was switched onto the Caps under test via a contactor.br br A 16 50 slide show is on part 2 of the videobr br A word of caution !br As mains voltages are involved here these experiments should not be copied without appropiate safety measures in place.