.............From my electrical principles at college many moons ago I seem to remember they can be put in parallel & the capacities added I think?.......
Cap = capacitor - which stores charge from the power supply to give smoothed DC. The larger capacity ones tend to by cylinders with a couple of terminals on top and markings on the side including something like 4700uF, 60V, meaning their capacity is 4700 microfarads and voltage rating is 60V. Capacitors will retain their charge, even after the charging source is removed, unless there is a path for current to flow, hence the bleed resistor which is connected across the capacitor to discharge it.
Ok thanks voipio.... i guess... it's somewhat clearer now... why do they store charge from the power supply???
mains electricity is AC Sparkey, cheap and easy to produce
one form or another yes,
The electric chair was developed by an employee of Edison and used AC.
Edison waged a campaign against AC saying it was far more dangerous than DC.
One of his demonstrations was the AC electric chair.
As a MIG welder works by striking an arc between the wire and the work piece this alone can generate large amounts HF radio energy causing interference with nearby electronic and/or radio equipment.
So I can't use my ham radio gear while I'm welding then?
Give it a try. I think you will get a burst of wideband noise as the arc strikes and continues. You may get away with it on 70cms FM, maybe 2m, but I think it will wipe out HF reception completely.