| 摘要 |
The current source (47) has outputs (CH1, CH2) providing constant currents (I1, I2) for operating electrical loads (10, 20). A dimming device (3) is provided for the outputs to conduct part of currents (I1', I2') flowing to the outputs to a reference potential (GND). The dimming device has switches (17, 27) controlled by a set of PWM signals (short1, short2). Another dimming device (4) has switches (12, 22) controlled by another set of PWM signals (open1, open2). A control unit controls the switches based on dimming position, and a current regulator is connected with a current modulator (1). |
