| 摘要 |
PROBLEM TO BE SOLVED: To obtain a temperature controller which does not affect the heater life adversely even when a different power supply is used by moving the timing of voltage application which is different according to the kind of a power supply voltage in the direction where an applied voltage falls in a temperature controller driving a heater by phase control. SOLUTION: A power supply voltage is defined as 240 V, and the voltage level at which the output of a photo isolator is integrated to be a direct current signal is subjected to A/D conversion and stored in a CPU 6. The timing (p) of a heater control signal at this time is also stored. Next, the power supply voltage is changed to 100 V, and a voltage level at which the output of the photo isolator is made an integrated direct current signal is subjected to A/D conversion and stored in the CPU 6. The timing (p) is forcedly changed while observing a heater waveform, and timing of when a rise of a C part comes to the same position as that of the time of 240 V is stored as p'. It is possible to realize the phase control with optimum timing all the time even through a power supply voltage fluctuates by monitoring an integral value from the relation between these two integral values and (p) and (p').
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