The capacitor (also called a condenser), is a self contained unit which is connected electrically in parallel with the contact breaker.
It is made up of two "plates" constructed from narrow strips of aluminum foil which are insulated from each other by a special waxed paper, called a "di-electric."
The plates and insulating paper are rolled up tightly together and sealed in a metal can by crimping the end over onto a gasket.
A spring in the base forces the plates and insulation against the gasket to keep out moisture.
One plate is connected to the capacitor case and, through its retaining screw, to ground.
The other plate is connected to the external connecting lead.
When the capacitor is fitted, any voltage surge across the contacts will charge the capacitor, rather than cause damaging sparking.
