| 摘要 |
The invention relates to a circuit for load-dependent rotation-speed control or for stabilising the rotation speed of a DC motor on no load and in the event of a suddenly applied load, especially for relatively small DC motors as are used, for example, for registration (accounting) machines. In order to achieve satisfactory load-dependent rotation-speed control at a low cost, the invention proposes a circuit in the case of which a voltage divider is provided between the terminals (V+, 0V) of the supply-voltage source, which voltage divider consists of a resistor (R1), a zener diode (V2; V21, V22) and a resistor (R3; R31, R32, R33) and to whose junction point between the zener diode (V2; V21, V22) and the resistor (R3; R31, R32, R33) the positive terminal of the motor (M) is connected, via a diode (V3; V31, V32), and the junction point between the resistor (R1) and the zener diode (V2; V21, V22) is connected to the base of a transistor (V1) whose emitter-collector junction is connected between the positive terminal (V+) of the voltage source and the positive input terminal of the motor (M), a control voltage (which is dependent on the respective load on the motor) being applied to the junction point between the resistor (R1) and the zener diode (V2; V21, V22) and to the base of the transistor (V1). <IMAGE>
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