| 摘要 |
<p>PROBLEM TO BE SOLVED: To start excitation current conduction at an accurate generation voltage value of a stator coil winding by discriminating the leading edge of a generated voltage which is generated by the magnetic flux of a permanent magnet on the basis of the physical quantity related to the leading edge of the generated voltage and feeding excitation current for the first time after detecting the leading edge. SOLUTION: When an engine is started, a rotor core 13 rotates and the magnetic flux of a permanent magnet 14 rotates and a generated voltage is induced in a stator coil winding 11. When a one-phase generated voltage Vac is smaller than a reference voltage V1 , transistors 80, 6, and 7 are turned off, no excitation current flows, and the consumption of a battery is prevented. On the contrary, when the voltage Vac becomes larger than the reference voltage V1, a comparator 8 generates a rectangular wave voltage according to the speed and the differential voltage periodically turns on the transistor 80. Even if the transistor 80 is turned off for a short period, the ON state of the transistor 6 is maintained, the switching transistor 7 is turned on, and the feed of excitation current is initiated.</p> |
