| 摘要 |
PURPOSE:To easily monitor the current and voltage waveforms of a main circuit by providing a control means which outputs the current and voltage waveforms in specific cycles of the main circuit according to the state of an external equipment corresponding to a setting signal from a setting means. CONSTITUTION:A transformer 2 for an instrument converts the voltage of a main circuit bus 1 into a signal corresponding to the transformation ratio and a converter 3 converts a current flowing through the bus 1 into a signal corresponding to the transformation ratio. A control circuit 8 inputs signals corresponding to the current and voltage waveforms of the main circuit from a voltage/voltage converting circuit 5 and a current/voltage converting circuit 6. Further, the signal from a breaker 4 is inputted, as well and when this signal goes to a signal corresponding to the setting information from a setting circuit 7, the signals in the specific cycles are outputted from the circuits 5 and 6 from the point of time. Then a storage circuit 9 is stored with the current and voltage waveforms of the main circuit in the specific cycles outputted from the circuit 8 and a display circuit 10 displays the current and voltage waveforms based upon the contents of the circuit 9. |
