| 摘要 |
Two ferromagnetic cores (11, 12) are provided for a transformer, only one of the cores (11) exhibits an air gap (13) in which a Hall effect element (3) is housed. The current flowing in a conductor (10) can be direct or alternating current and induces in the core (11) a corresponding magnetic field which makes it possible to obtain a signal on the element (3). This signal is amplified by an amplifier (8). The output current from amplifier (8) is applied to a winding wound around both cores (11, 12). For direct current and low frequency current, the winding current is proportional to the current in conductor (10). When the frequency of the current flowing through conductor (10) exceeds a certain value (several kHz), the gain of the amplifier (8) diminishes. A linear relationship between the conductor current and the current in the winding is maintained, however, because the high frequency is transmitted to the winding by the core (12). |
