| 摘要 |
PURPOSE:To reduce the influence of a rush current upon an AC load, by controlling the power supply mode of a heater in accordance with the time of turning- off of the heater in the temperature control of a copying machine or the like. CONSTITUTION:In a fixing device of a recorder such as a copying machine or the like, the temperature detection signal from a thermistor TH103 is inputted to a terminal A1 of a mcrocomputer muCM100 incorporating an ROM, an RAM, etc., and the muCM100 converts this signal digitally. An H-level signal is inputted to the interrupt terinal near the zero-corssing point of an AC power source through a full-wave rectifying circuit 101 and an inverting amplifying circuit 102, and the muCM100 executes an interrupt program by the rise of a pulse signal to control a halogen heater 104 from an output port R1 through a driver 105. The muCM100 detects the turning-off time of the power supply of the heater 104 and performs such control that the power supply mode at the heater turning-on time is different in accordance with the turning-off time, and thus, the time of variance of the power source for the power supply to the heater is reduced. |
