| 摘要 |
PURPOSE:To suppress abrupt variation in the turn-on voltage of a lamp, converge the turn-on voltage of the lamp on a desired value speedily, and prolong its life by inhibiting a fixing heater from being switched on and off during the operation of soft starting mechanism. CONSTITUTION:The controller for the halogen lamp 2 consists of a power source 1, gate control rectifying circuit 5 for a triac 3, trigger element 6, zero- cross circuit A, detecting circuit B for the lighting operation and effective value of the lamp 2, microcomputer 27, etc. The microcomputer 27 performs turn-on voltage control over the lamp 2 and temperature control over a fixing heater 30, and is equipped with the soft mechanism which increases the phase control angle in at least every half cycle of the voltage of the power source 1 to the lamp 2 at prescribed time intervals after a copy key is operated for the turn-on voltage control; and the heater 30 is inhibited from being switched on and off during the operation of the mechanism. |
