CONTROL CIRCUIT FOR CONTROLLING VOLTAGE SUPPLY OF ELECTRIC DEVICES

摘要

A control circuit for controlling the voltage supply to selected ones of a plurality of output terminals to which controllable devices are connected to is described. The control circuit comprises manually operable function switches which are connected to an integrated circuit providing output logic signals to feed an interlock circuit to select the operation of one or more of a plurality of high voltage electronic switching devices. An interface circuit is connected between the switching devices and the interlock circuit to trigger the operation of selected switching devices to connect a high voltage supply to associated ones of the output terminals. The interface circuit also prevents feedback voltage surges from the one or more switching devices to protect electronic circuits in the control circuit. An overcurrent protection circuit is connected between an output of the high voltage electronic switching devices and the integrated circuit to disable the output logic signals and the interlock circuit to cut the high voltage supply at the output terminals when the current exceeds a predetermined reference value.