Abstract: There is described a semiconductor switch device having two semiconductor components, the first component receiving drive signals from the second. The first component contains either a single power bipolar switch element for single ended control of the energisation of a load or a bridge of such elements enabling energisation of a load with different polarities. The switch elements, which may be transistors or darlington multiple transistors, have voltage dropping elements connected in the leads to their control bases, so that the drive signals from the second component can be produced by low impedance connection to one or the other supply conductor, thereby keeping the power dissipation of the second component to a low value. The voltage dropping elements may be a series resistor or a constant current circuit.

Abstract: There is described a semiconductor switch device having two semiconductor components, the first component receiving drive signals from the second. The first component contains either a single power bipolar switch element for single ended control of the energization of a load or a bridge of such elements enabling energization of a load with different polarities. The switch elements, which may be transistors or darlington multiple transistors, have voltage dropping means connected in the leads to their control bases, so that the drive signals from the second component can be produced by low impedance connection to one or other supply connductor, thereby keeping the power dissipation of the second component to a low value. The voltage dropping means may be a series resistor or a constant current circuit.