| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a period and phase detection mode control device and method capable of accurately detecting periods and phases of various input voltage whose value is undetermined and varies periodically.SOLUTION: A period detection mode control device comprises: an AC voltage sensor 12 for detecting input voltage from a periodic shifting voltage source 11 such as an AC power supply, and a half-wave or full-wave rectification power supply; a maximum value/minimum value detection unit 13 for monitoring the input voltage during predetermined time to acquire a maximum value and a minimum value of the input voltage; and a period/phase detection processing unit 14 that selects, on the basis of the maximum value and the minimum value of the input voltage detected in the maximum value/minimum value detection unit 13, at least one period detection mode from a plurality of period detection modes in which detection of a period and a phase of the input voltage is performed by detecting timing of the input voltage's changing across any of a plurality of voltage thresholds, and detects the period and the phase of the input voltage in the selected period detection mode.</p> |
