| 摘要 |
PURPOSE:To make possible an exact frequency discrimination by providing a pulse interval measuring means and outputting a result in which the most frequency of counted number is made a power source frequency. CONSTITUTION:When a pulse is input within a microprocessor 110, an interruption occurs at a trailing edge of the pulse or a rising edge thereof, is received within an outside interruption processing part 103 and an interval of time of the outside interruption is measured within a pulse width measuring part 104. Within a pulse width measuring part 105, measured values are compared with a standard value, and within a counting part 106 count of 50Hz or 60Hz is counted up from the comparison result. Next, when within a measuring finish discrimination part 107, measuring finish is discriminated, the counted values of 50Hz and 60Hz counted within the counting part 106 are compared with each other with a size comparison part 108 and the discrimination of 50/60Hz is performed within a 50/60Hz discrimination part 109. |
