| 摘要 |
<p>PURPOSE:To detect the electric current in both forward and backward directions easily, by providing a Hall CT differential amplifier circuit and an inversion circuit to a DC main circuit of an inverter, and matching the signal passing said inversion circuit and the signal emitted straightly from the amplifier circuit through a diode. CONSTITUTION:The current value in the MO direction or DB direction flowing in the main circuit electric wire 11 in the DC part of an inverter is detected with a Hall element 12. The Hall element is usually embedded in a core consisting of an electrical iron plate in order to improve a detection characteristic. Optimum excitation current is applied through a resistor 14 to the element 12 from an electric power source 13 for applying excitation current. The voltage generated in the Hall element is conducted to an amplifier circuit 10 in the next stage. For the voltage detected with the Hall element, the voltage e3 by an amplifier circuit A and the voltage e4 passing through an inversion circuit B of a gain=1 are rectified and the voltage e5 is obtained. The current in the stage of control is also detected as the DC voltage in the forward direction.</p> |
