Bi-directional DC power controller with fault protection

摘要

A bi-directional DC power controller is provided with a bi-directional DC switch (10) connected between a pair of terminals (12, 14) for connection to a pair of line power conductors (16, 20). A pair of difference amplifiers (U2, U3) are connected to receive voltages at these terminals. Each amplifier produces an output voltage signal which is proportional to the difference in voltages between these terminals when the voltage at one of the terminals is greater than the voltage at the other terminal, and is constant when the voltage at the second terminal is greater than the voltage at the first terminal. The outputs of the difference amplifiers are combined to produce a control voltage signal having a magnitude that is proportional to the absolute value of the difference between voltages at the terminals. This control signal is used to control the operation of the bi-­directional DC switch.