Patent ID: 9160343
Filing Date: 2015-10-13
Classification: H03B,H03L,H05B

Abstract:
1. A heater device, comprising: a temperature detector, configured to detect a temperature of a temperature-controlled object; a heater control circuit, configured to output a control voltage based on a temperature detection value of the temperature detector, and a temperature target value; a heater, configured to cause heat generation by supply of the control voltage from the heater control circuit, and to provide higher output as the control voltage decreases, so as to heat the temperature of the temperature-controlled object to a target temperature; a voltage supply path, configured to supply the control voltage to the heater; and an overheat prevention circuit, configured to prevent excessive heat generation of the heater when the heater control circuit becomes abnormal, wherein the overheat prevention circuit includes: wherein the control voltage to be applied to the heater is restricted to a voltage at a connection point between the positive-temperature-coefficient thermistor and the pull-up resistor, when the control voltage from the heater control circuit abnormally decreases.