Feedforward circuit for pulsewidth modulating circuit

• Main Authors: ZHANWEI LI, QIHAO ZHONG, XUEJUN ZHANG
• Format: Patent
• Language: Chinese; English
• Published: 07.01.2004
• Edition: 7
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION

The utility model provides a feedforward circuit for the pulse width modulation circuit, which consists of a driving circuit whose output end is connected with the control signal input end of the pulse width modulation circuit and is characterized in that: the utility model also consists of a sawtooth generator and a comparator, wherein the input end of sawtooth generator is connected with the input voltage and the output end is connected with the input end of the comparator whose output end is connected with the input end of the driving circuit. The higher the input voltage, the smaller the inputted pulse width is. Otherwise, the larger the pulse width is, the lower the input voltage is, thereby realizing the stability of the input voltage or the simplification of the subsequent voltage stabilizing circuit. 本实用新型提出一种用于脉宽调制电路的前馈电路，包括一个驱动电路，其输出端接于脉宽调制控制电路的控制信号输入端，其特征是：还包括锯齿波发生器、比较器，所述锯齿波发生器的输入端与输入电压相连，输出端与比较器的输入端相连，比较器的输出端接驱动电路的输入端。输入电压越高，输出脉宽越小，反之则脉宽越宽。这样就可以实现输出电压稳定，或者使后续的稳压电路简化。