| 摘要 |
<p>PURPOSE:To reduce an influence of a secondary impedance and to eliminate a need for an auxiliary current transformer, a tertial winding and a toroidal core by a method wherein an output voltage of an operational amplifier is applied to a terminal of a secondary winding and it is adjusted by using a specific circuit structure. CONSTITUTION:Since an output voltage V0 of an operational amplifier 2 is applied to the other end of a secondary winding 1b, a voltage-dividing ratio of impedance circuits 10, 11 is adjusted according to a secondary impedance, the output voltage V0 of the operational amplifier 2 is adjusted and an error can be compensated. When the error is compensated excessively, a magnetic flux is generated inside an iron core of a current transformer 1 by an excess voltage. Since an excitation impedance is connected in series, a secondary current is suppressed and the amplifier is operated stably. Consequently, even when an amplification factor of the operational amplifier 2 is set erroneously, an influence of the secondary impedance can be reduced. Thereby, it is possible to obtain a current transformer device which is operated surely against a half- wave rectification waveform, which is small-sized and whose cost is low.</p> |
