Patent ID: 6691923
Filing Date: 2004-02-17
Classification: G05D,H05B

Abstract:
A low noise solid state thermostat, comprising:a thermostat input operatively configured to be coupled to a temperature sensor; a comparator for comparing an output of the temperature sensor to a predetermined set-point temperature; and solid-state switching circuitry operatively coupled to the comparator for selectively switching current to a thermostat output based on an output of the comparator, wherein the solid-state switching circuitry includes means for providing soft switching between an on-state in which current is provided to the thermostat output and an off-state in which current is not provided to the thermostat output, the thermostat operates based on an AC power supply, and the means for providing soft switching causes a rate of change of current provided to the thermostat output to be substantially the same as a rise and fall rate of the AC power supply.