Patent ID: 7944665

Claim:
An electric control and protection system for an output channel of automation equipment, the output channel being capable of controlling an electrical load as a function of a control signal from the automation equipment, the control and protection system comprising: a device that switches the electrical load including an MOS switching transistor, a source of the MOS switching transistor being connected to a positive voltage terminal via a resistor and a drain of the MOS switching transistor being connected to the electrical load, the MOS switching transistor being switchable between an on-state in which the electrical load is connected to said resistor and an off-state; a limiting device that limits a voltage at terminals of said resistor to a predetermined maximum value; and an output channel cut-off device that switches the switching transistor to the off-state when a current flowing through said resistor passes a predetermined threshold for a predetermined duration, wherein the limiting device includes, a bipolar transistor, an emitter of which is connected to the source of the switching transistor and a collector of which is used to control a gate of the switching transistor; and a voltage-drop element connected between the positive voltage terminal and a base of said bipolar transistor, a voltage drop at terminals of the voltage-drop element being approximately equal to a sum of a base-emitter voltage of said bipolar transistor and a predetermined maximum value at the terminals of said resistor.