| 摘要 |
<p>PURPOSE:To obtain quickly a set temperature by comparing the voltage divided by a resistance connected in series to a temperature detecting element with the reference voltage and controlling the phase angle of the voltage impressed to a heating element. CONSTITUTION:A temperature sensor 15 which detects the temperature of a heating element 8 and varies its resistance is provided together with voltage dividing resistances R4-R7 which are connected in series to the sensor 15. The voltages divided by the resistances R4-R7 are given to voltage comparison elements 11-14 respectively and compared with the reference voltage. The outputs of the elements 11-14 control transistors (TR) Q1-Q4 respectively, and the specific resistance value of a phase control circuit is changed in steps by the each output of TRs Q1-Q4. Thus a bidirectional control element 9 controls the heating value of the element 8. In such a way, a set temperature can be obtained quickly.</p> |
