| 摘要 |
A rotation speed controlled multi-pole pair d.c. motor (1) is to be operable at least two working points (10, 20). Upstream of the pole pairs of the motor (7) is an electronic circuit which connects or disconnects the individual pole pairs by their brushes (11, 14) to or from the power supply, e.g. a battery (5), via controllable switches (21, 22). The individual pole pairs are connected or disconnected to or from the power supply depending on the load demands and the voltage (Un) available from the non-conducting brushes (14) which is proportional to the rotation speed (n) of the motor (1). |
