| 摘要 |
The electromagnetic braking arrangement comprises an exciting winding which is supplied from a generator winding which on the one hand excites the generator winding and on the other hand induces a braking torque in a short-circuited winding moved with the generator winding. The excitation current of the exciting winding is controlled by a transistor of a current-regulating circuit which holds the excitation current and thus the braking torque at a level adjustable at a reference voltage source. The iron circuit of the exciting winding has residual magnetic properties which ensure an initial self-excitation. The components of the control circuit are supplied with operating voltage from the generator winding via a rectifier circuit. A resistor, which is directly connected to the rectifier circuit, controls the transistor in the conductive state even when the operating voltage is insufficient for proper operation of the control circuit. It is thereby achieved that the braking arrangement is able to operate even with comparatively low magnetic circulation. |
