Patent ID: 7499252

Claim:
A switch control system comprising a driver circuit for an electronic switch, the driver circuit having a first input for receiving a first control signal, the driver circuit further including a shut-off circuit for operating the electronic switch to cause an interruption to the current flow in the event of a fault condition arising, wherein operation of the shut-off circuit can be temporarily invoked by initiation of the first control signal instructing the driver circuit to place the switch in a low impedance state; the control system further comprising a controller having a monitor input for monitoring a voltage occurring across a load, current flow through a load or a control signal supplied to the electronic switch so as to determine an operational state of the switch, and wherein the controller is arranged to monitor the time taken for the switch to close in response to initiation of the first control signal instructing the driver circuit to place the switch in a low impedance state, and the controller is arranged to indicate that the shut-off circuit is faulty if the switch switches on within a first predetermined time period.