| 摘要 |
PROBLEM TO BE SOLVED: To provide a dirt detecting circuit of an ionizer discharge needle and a dirt detection method of an ionizer discharge needle, capable of capturing very small change due to existence of corona discharge of a discharge needle, with a small effect due to environmental changes such as difference of an installation place or change of power source voltage, and capable of preventing incorrect detection. SOLUTION: The dirt detecting circuit 100 of an ionizer discharge needle generating ions by corona discharge is provided with a piezoelectric transformer 120 outputting high voltage to a discharge needle 130, a voltage control oscillation part 110 receiving feedback of the output voltage of the piezoelectric transformer 120 and controlling input voltage to the piezoelectric transformer 120, a phase comparing part 160 outputting waveforms corresponding to a phase difference between the input voltage and the output voltage to the piezoelectric transformer 120, and a voltage comparing part 190 comparing an integrated value of the output of the phase comparing part 160 and a reference voltage. When the integrated value is lower than the reference value, the circuit 100 detects dirt of the discharge needle 130. COPYRIGHT: (C)2011,JPO&INPIT |
