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US 4,634,046 AGranted
Control system using combined closed loop and duty cycle control functions
AssigneeYamatake-Honeywell Co., Ltd.
InventorMinoru Tanaka
Life of this patent
Estimating the term…
Abstract
A control system having combined closed loop and duty cycle functions uses a differential amplifier for amplifying the difference between a setpoint or reference temperature for a system to be controlled and a detected system temperature, a thermostat having a differential circuit for providing a predetermined hysteresis lag for an output of the amplifier and a duty cycle generating circuit for changing the operating potential of the differential circuit in accordance with a predetermined duty cycle to shift the operating point of the differential circuit.
Claims4
A control system comprising
- a differential amplifier for amplifying the difference between a preset reference temperature for a controlled system and a detected temperature in the controlled system,
- thermostat means having a differential circuit for providing a predetermined hysteresis lag for an output of said amplifier, and
- a duty cycle generating circuit for changing the operating potential of said differential circuit in accordance with a predetermined duty cycle thereby to shift the operating point thereof wherein said duty cycle generating circuit includes a comparator for comparing output of a saw-tooth generating circuit and the output of an ambient temperature sensor for providing an output corresponding to the difference therebetween.
Dependencies are inferred from the claim text.