| 專利摘要 | A PWM controlling circuit includes a signal generator and two PWM controllers. The signal generator comprises an oscillator, a plurality of inverters, and two RC delay networks. The oscillator and the inverters are composed of elementary elements, respectively, such as diodes, resistors, inverters and capacitors. The PWM controlling circuit in accordance with the present invention can be implemented with low cost, and the duty cycles thereof are not limited to 50%. |