Patent ID: 8742301

Claim:
A heater apparatus, comprising: a heater unit including a heater resistor; a temperature sensor which senses a sensor temperature around the heater unit; a first switching unit which is disposed on a downstream side of the heater resistor for on/off controlling a power supply path from a supply voltage; a second switching unit which is disposed on an upstream side of the heater resistor for on/off controlling the power supply path from the supply voltage; a controller which outputs first and second control signals for on/off controlling the first and second switching units, respectively; and a third switching unit which reverses the second control signal and outputs the reversed second control signal to the second switching unit, wherein the first switching unit is switched on when the first control signal is high, and the second switching unit is switched on when the second control signal is low, and wherein the controller controls the first and second switching units, such that the first and second switching units are controlled so as to switch on the heater unit when the sensor temperature is equal to or lower than a first threshold and so as to switch off the heater unit when the sensor temperature is equal to or higher than a second threshold.