Abstract: An automatic var control unit which monitors the reactive volt-amperes of a load on electrical lines, and continuously compensates undesired var by switching onto or from the lines of compensating capacitance. More particularly, the var condition on the electrical lines is sensed, converted into a representative analog voltage, which voltage is then amplified, compared and converted in logic circuits into a first binary pulse representing the need to add/remove capacitance. A flip/flop logic circuit controls by a second binary pulse the addition or removal of capacitance. These binary pulses control the sequencing of relays that perform the actual switching of capacitors in the capacitor bank relative to the electrical lines. The capacitors in the capacitor bank can be switched in series or in binary progression, according to a program in the controller. As a result, the power efficiency of the lines is raised to above 90% by the automatic cancellation of the inductive load reactances.