| 摘要 |
PROBLEM TO BE SOLVED: To provide a temperature control circuit for a turbo-molecular pump, which is capable of warming under the right warm-up conditions against the different power supply voltage specification. SOLUTION: A temperature-detecting device 2 detects inside pump temperature warmed by heater 1 and the turning-on electricity calculation device 6 calculates the heater on time per unit time using the temperature difference between target temperature and detected temperature. At the same time, the electric current detecting device 3 detects the heater current, electric current square value device 4 integrates electric current square value, heater control device 5 compares electric current square limit value 7 with electric current square value, if electric current square value exceeds its limit value, even it is within the range of turn on electricity hour determined by turn on electricity calculation device 6, remaining time in the heater control unit time shields the heater current by the signal from the heater control device 5 to the switching element 9.
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