| 摘要 |
<p>PROBLEM TO BE SOLVED: To detect the voltage of a power source having a fairly high voltage while preventing enlargement of a circuit, increase of cost, increase of heating, reduction of a detection accuracy and so on. SOLUTION: The voltage of a power source 17 is divided by first and second potential resistors R1, R2 connected to the power source 17 and a potential difference V1 appearing between both ends of the second resistor R2 is converted to a primary current I1 corresponding to the potential difference V1 by an FA converter 33 to allow to flow the primary current I1 in a primary coil 3 and resistor 7. A primary magnetic fluxΦ1 generated in a magnetic core 1 by the primary current I1 flowing in the primary coil 3 and load 19 is canceled with a secondary magnetic fluxΦ2 generated in the magnetic core 1 by a secondary current I2 allowed to flow by a current buffer 15 in a secondary coil 5 based on an output voltage generated by a Hall element 11 corresponding to the primary current I1 . Thereby, a potential difference V2 usable for detecting the voltage of the power source 17 is generated between both ends of a detecting load 21 connected to the secondary coil 5.</p> |
