| 摘要 |
PURPOSE:To easily ensure maintenance of developing gas temperature of a diazo copying machine or the like at a constant temperature and detection of disorder, by changing over a rate of power supply to a heater to prescribed 3 modes in accordance with a developing gas temperature detected. CONSTITUTION:Developing gas temperature is detected with a thermistor 4, compared with a low temperature reference set voltage in a comparator 6, and when the detected value is not higher than the set voltage, a transistor 7 is turned on via the comparator 6 to energize a relay RAX-1. As a result, a TRIAC2 is turned on to feed 100% AC power to a heater 1 and to raise its temperature suddenly. On rising to or above a prescribed temperature, the relay RAX-1 is degaussed and 50% AC power subjected to half-wave rectification with a diode 3 is fed to the heater 1. When temperature rise to or above the set value is detected with a thermistor 4 or detection of the temperature is made impossible by disconnection of the thermistor 4, the relay RAY-1 is likewise degaussed to stop power supply and at the same time to sound an alarm. |
