CURRENT DETECTING CIRCUIT AND TRANSFORMER CURRENT MEASURING SYSTEM

摘要

Provided are a current detecting circuit and a transformer current measuring system, wherein transformer currents (primary current and secondary current) can be measured without deteriorating operations of an element and a circuit even when a transformer having a large excitation inductance is used in the cases where the element and the circuit which do not normally operate without using a transformer having a small excitation inductance are connected to the primary side. A current detector (CT) (current transformer) is connected in series to the primary winding (111) of a transformer (11), and an inductor (La) is connected in parallel to the serial connection of the primary winding (111) and the current detector (CT). Based on the value of a primary current (IT) detected by means of the current detector (CT), the secondary current (I2) of the transformer (11) is measured.