| 摘要 |
PURPOSE:To raise the temperature of a body to be heated up to prescribed temperature speedily and to prevent the generation of a temperature ripple, by using a thermistor as a temperature sending element, and powering up and controlling two heaters through a relay and thyristor. CONSTITUTION:An AC power voltage is passed through a resistance 5, rectified by a diode 6, and smoothed by a capacitor 7. Further, the resulting voltage is made into a constant voltage by a tesistance 8 and a constant-voltage diode 9 to obtain a constant-voltage power source for a gate circuit and a base circuit. When the output of a comparator 15 goes down to a level LOW, a thyristor 10 turns off. When the output of the comparator 15 goes up to a level HIGH, on the other hand, a signal is supplied through a resistance 16 to the gate of the thyristor 10, which turns on to power up a heater 2. |
