Patent ID: 6501342
Filing Date: 2002-12-31
Classification: G05G,G06F,H03K,H03L,H03M,Y02D

Abstract:
An apparatus with first, second, and third terminals, the apparatus comprising:an oscillator having a control line, the oscillator responding to the control line being in a first state by providing an oscillator output; control logic powered by the first and third terminals, the control logic connected with and controlling the control line; a first switch and a first current sensor having a first output in series between a first one of the first and third terminals via and the second terminal, the first switch controlled by the control logic, the first output connected with and provided to the control logic; a second switch connected to a second one of the first and third terminals, and connected to the second terminal, the second switch controlled by the control logic; the control logic characterized in that upon the condition of the first output being indicative of current in excess of a first predetermined threshold, the control logic actuates the control line whereby the oscillator oscillates, yielding an oscillating signal at the oscillator output; the control logic responsive to the oscillating signal by repeatedly turning on the first and second switches in alternation according to the oscillating signal; the control logic further characterized in that upon the condition of the first output being indicative of current below a second predetermined threshold, the control logic deactuates the control line whereby the oscillator ceases oscillation; the control logic comprising means preventing simultaneous turning on of the first switch and the second switch.