| 摘要 |
PURPOSE:To allow the high-precision temperature control by using a conductive material for a heat roller and utilizing the change of the resistance value due to its temperature to control the temperature. CONSTITUTION:A current is fed to a heat roller with the temperature coefficient other than '0' from a DC power supply Vcc via a pair of metal contact pieces 3, and the voltage of the DC power supply VCC is divided with a resistor 9 and the heat roller 1. When the temperature of the heat roller 1 is increased by a heater 2, the resistance value between a pair of metal contact pieces 8 is changed by the temperature coefficient of the heat roller 1. The change of this resistance value changes the voltage at a connection point 8 and operates a comparator 7, and a relay 5 is turned on or off by the control of a relay control circuit 6. If the temperature coefficient of the roller 1 and the reference voltage of the comparator 7 are properly selected, the temperature of the heat roller 1 can be controlled with high precision.
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