| 摘要 |
The invention relates to a brushless type DC motor assembly of the type having a permanent magnet rotor and a pair of poles provided with two windings, the windings having a common junction which is connectable to the positive terminal of a DC voltage source. A pair of controlled rectifiers in respective series with the windings are followed by a series branch having a smoothing choke and an electronic chopper switch, the series branch being connectable to the negative terminal of the DC voltage source. The invention is directed to an improved circuit permitting operation of the motor at higher power by providing an extinguishing circuit for the controlled rectifiers which includes a series arranged extinguishing capacitor and a swingover choke that connects the upstream sides of the controlled rectifiers. The extinguishing circuit also includes extinguishing diodes connected in antiparallel respectively to the rectifiers. At least one free running diode is provided which bridges at least the smoothing choke and the chopper switch. |
