A SWITCHABLE LOAD FOR INITIALIZING AN OUTPUT VOLTAGE OF A POWER SUPPLY

摘要

A conductive transistor switch has a collector that applies a reset pulse to an electronic circuit. A pull-up resistor is coupled between the collector of the transistor switch and a power supply voltage developed in a filter capacitor that energizes the electronic circuit. Proper reset operation requires the output supply voltage not to exceed, for example, 0.2 volts, during at least a portion of the reset operation. The user initiates the reset pulse that momentarily disables a power supply for ceasing the generation of the output supply voltage when the reset operation is performed. The value of the resistor is selected to be sufficiently low such that when the transistor switch is conductive, the discharge of the filter capacitor via the pull-up resistor is speeded up for completing the discharge of the filter capacitor in no more than, for example, 2 seconds to provide a maximum level of the output supply voltage that is no more than 5% of its normal operation voltage level.