| 摘要 |
A permanent magnet alternator (PMA) 20 includes a rotatable shaft 52, windings 22A, 22B, 22C, a shunt regulator circuit 30, and a speed detection circuit 100. The rotatable shaft: is connected electromagnetically to the windings. The shunt regulator circuit is electrically connected to the windings. A current sense transformer with a primary coil is electrically connected to the shunt regulator circuit. A secondary coil is electrically connected to a comparator circuit with a reference voltage and generates a voltage pulse indicating the PMA speed. The shunt regulator circuit may include a first lead connected to ground through a first MOSFET, a second lead connected to ground through a second MOSFET, and a reverse flow leg having a first end connected between the second MOSFET and the second lead, and a second end connected to ground. The primary coil of the current sense transformer is connected to the ground and second lead through the reverse flow leg, and the secondary coil is electromagnetically coupled to the primary coil and electrically coupled to a second ground for generating voltage pulses indicating the shaft rotation speed using current returning to the second lead through the shunt regulator circuit. |
