| 摘要 |
PURPOSE:To prevent the output current of a DC power source from flowing to a power source by providing a parallel circuit of a switch and a current limiting element in series with the prescribed DC power source, and opening the switch when a coil energizing current due to the DC power source of other side is made to flow. CONSTITUTION:A parallel circuit of a switch 8 and a resistor 9 of a current limiting element is connected in series with a DC power source 5 for a bias coil, provided in series with a DC power source 4 for a current transformer coil, a start switch 10 inputs an open/close state signal of the switch 10 for turning ON or OFF a power source with respect to a current transformer coil 2, and controls to close the switch 8 when the switch 10 is open and to open the switch 8 when the switch 10 is opened. Thus, the induced current from the coil 2 is reduced to decrease the power source loss. |
