Low power loss voltage supply circuit

Claim 1

In a d-c power supply having an input terminal at which a d-c voltage level is generated, circuit means for generating a reduced d-c voltage level at a circuit output terminal, the combination comprising: a first electronic switch having a first load current conducting element connected to said input terminal, a second load current conducting element connected to said output terminal, and a control element; bias current supply means connected to said control element to supply current thereto which drives said first electronic switch into a fully conductive state; an energy storage element connected to said second load current carrying element to receive and store electrical energy when said first electronic switch is fully conductive and to develop a voltage which is proportional thereto; a voltaGe responsive gating device connected to said energy storage element and being operable to generate signal current when the voltage developed by said energy storage element reaches a preset maximum level and to discontinue generation of said signal current when said voltage diminishes to a second, preset minimum level; and a second electronic switch having a control element connected to said voltage responsive gating device and a current conducting element connected to said bias current supply means, wherein said second electronic switch is operable to divert bias current from the control element of said first electronic switch when signal current is received from said voltage responsive gating device to thereby drive said first electronic switch into a non-conductive state in which no energy is supplied to said energy storage element, and wherein said second electronic switch is operable to allow bias current to flow to said first electronic switch control element when said signal current is not received from said voltage responsive gating device.