| 摘要 |
The invention to an electronic control system, controlled by a pulse width-modulated signal (SG) related to earth, for regulating the voltage (Umot) across a high-side load (M), in particular a fan control unit for motor vehicles. The circuit part that converts the pulse width-modulated signal (SG) into the reference input variable (U−) needed for the regulation uses the positive potential of the supply voltage (V2) as reference potential, so that the reference input variable (U−) is likewise related to the positive potential of the supply voltage and the control signal (SG) is converted by means of a Zener diode (D1) and by means of a resistor (R5) connected parallel to the Zener diode (D1) into a control signal related to the positive supply potential and is further converted with a low pass filter (R7, C1) into a linear control signal, which serves as input reference variable (U−). |
