| 摘要 |
PURPOSE:To improve reliability by performing temp. controlling of a fixing heater, and electric power controlling of AC load such as exposure controlling of an exposure lamp by digitally processing signal by the use of a microcomputer. CONSTITUTION:The analog signal from a thermistor 18 provided near a lamp 20 for a fixing heater or the like of the copying machine is inputted via a linearizer 19 to a microcomputer 1, which in turn starts a counter at every zero cross point of the AC applied to a lamp 20, allows the counter to time up by selecting the time-up time of the counter from those having beforehand been determined, and controls an AC switch 21 consisting of a triac or the like by the signal obtained through an extension input-output interface 2. Hence, electric power controlling is accomplished easily digitally, and further the supply electric power to the lamp 20 is changed continuously. |
