| 摘要 |
A protection circuit for a DC motor which has no commutator and is excited via at least two power transistors whose collector currents supply the stator winding, the sum of the stator currents being supplied to a measuring resistor (30). The voltage drop across this measuring resistor (30) is supplied via a delay stage (27, 28, 29) to the one input (24) of a comparator stage (22) whose other input (23) is supplied with a limiting-value signal in the form of a predetermined voltage value. If this limiting-value signal is exceeded by the output signal of the delay stage, a switch-off command for the at least two power transistors is formed. <IMAGE> |
