| 摘要 |
PURPOSE:To obtain a watthour meter wherefrom an output pulse can always be transmitted as a pulse of an optimum pulse width, by providing a means of determining a maximum pulse width which can secure the ratio between ON and OFF times of the output pulse. CONSTITUTION:When V/A is 110V/5A, a set transformation ratio 200, a multiplying factor 1 and a pulse weighting multiplying factor 1/100 in a three-phase three-wire system, for instance, output pulses per one hour in the case of a rated load are 19.060 and an input range is 19.060X1.5=28.590, since it is allowed to be 1.5 times at the maximum. A pulse period in this case is 3,600divided by 28.590=126ms, and therefore a microcomputer unit 7 makes determination that the regulation of the pulse period being 144ms or above is not met when an ON time is 120ms and an OFF time 24ms or above. Since the pulse period is 126ms as calculated in the above, the regulation is determined to be met when the ON time is 60ms and the OFF time 66ms. Thereby the output pulses can be optimized. |
