Power control unit for a computer system

Claim 1

In a power control unit for controlling the electrical power source of a system including a main computer with a source battery for generating a system source voltage and a peripheral device having a higher operating voltage than said system source voltage and a source voltage generator circuit which generates a source voltage corresponding to said operating voltage, the improvement wherein said power control unit comprises a first voltage generating means connected to a system bus for generating a lower voltage, a second voltage generating means for generating a higher voltage, a control means serving to output a high output signal or a low output signal, depending on whether an output of power at said higher voltage through said system bus is desired or not, a first transistor having the base thereof connected to said control means and the emitter thereof grounded, and a second transistor having the base thereof connected to the collector of said first transistor, the emitter and the base thereof connected to said second voltage generating means and the collector therof connected to said system bus.