ABSTRACT
Loads like transformers, motors, and ballasts are inductive and by adding capacitance to the circuit, it causes the voltage and current to come back in phase with each other. If the capacitive reactance exactly equals the inductive reactance, then they fully cancel and the load becomes purely resistive. Otherwise it will only be partially power factor corrected. Most automated lighting fixtures with a magnetic ballast power supply have a power factor correction capacitor. You may also see banks of large, oil-filled capacitors on transmission towers or in electrical substations, particularly in industrial areas that consume lots of power, for the same reason
FIGURE6.S An LED emitter from a string of Christmas lights. The only circuit elements are a bridge rectifier and two capacitors.
