| 摘要 |
PURPOSE:To reduce the load factor of each used machine to extend the life and to reduce the cost by connecting electric power transformers as equivalent loads between lines to eliminate the unbalance of load between lines. CONSTITUTION:Electric power transformers 21 and 22 are connected between lines and individual or shared DC stabilized power supply circuits 23 and 24 are connected to output terminals of these transformers. A switching signal is issued from a timer circuit 26 to switch a changeover switch 25 at intervals of a prescribed time, and power transformers 21 and 22 are selected and used alternately, and a prescribed DC voltage is outputted from circuits 23 and 24 and is supplied to each required constituting element of a watthour meter. A signal proportional to the load voltage of a three-phase three-wire distribution line and a signal proportional to the current consumption are multiplied by power-voltage converting circuits 15 and 16 to obtain power, and this power is converted to a voltage signal proportional to it, and this signal is converted to pulse having a frequency proportional to power by a voltage-pulse converting circuit 17, and these pulses are weighted properly by a frequency dividing circuit 18 and are displayed as an electric energy on a display device 19. |
