| 摘要 |
PROBLEM TO BE SOLVED: To easily correct a phase shift without increasing cost, and to enhance measurement accuracy of a power measuring device, even if many kinds of current detectors are used in its current detection circuit. SOLUTION: Based on a phase shift amount set in a phase-shift amount setting part 37, a time adjustment part 36 outputs trigger signals for determining timings of respective capturing of a voltage signal and a current signal i.e. start timings of AD conversions, as performance timings of the AD conversions to AD converters 31, 32 individually. In the phase-shift amount setting part 37, a phase shift amount (adjustment time)Δt in accordance with the kind of a current detector is set. The time adjustment part 36 sends the trigger signal out to the AD converter 31 to make it start performing the AD conversion of the voltage signal. After the adjustment timeΔt passes, the trigger signal is sent out to the AD converter 32 to make it start performing the AD conversion of the current signal. A multiplier 34 calculates a power value by multiplying the digital value of the time-adjusted voltage signal and the digital value of the current signal. COPYRIGHT: (C)2011,JPO&INPIT |
