DZW75-48/50(50II) power factor compensation

DZW75-48/50(50II) power factor compensation principle diagram: DZW75-48/50(50II) power factor compensation circuit: As shown in the figure, (a) is the compensation circuit and (b) is the auxiliary power supply. It is mainly composed of N1, power factor correction control module and some supporting circuits. N1 is internally composed of a sawtooth wave generator, pulse width modulator and various comparator circuits. The sawtooth wave generator determines its operating frequency through external capacitors and resistors. The frequency of the output pulse of this machine is 50kHz, and the width of the output pulse is determined by the error voltage after comprehensive comparison. It has 3 sampling comparison circuits. The output voltage sample is sent from the divided voltage value of R19 and R20 at the output end to pin 11 of N1 through R16, and to pin 7 of N1 through V1; the power and current waveform samples are obtained from the small resistor R18 connected in series in the switch circuit. It is sent to pins 2, 3, 4, and 5 of N1 through the resistor and capacitor network respectively; the reference 100Hz pulsating voltage waveform is obtained from the output end of the bridge rectifier, and is sent to pin 6 of N1 through resistors R14, R2, R6, etc. , 8 feet. Pin 1 of N1 is connected to ground, and pin 15 is connected to the working power supply (18V). N1 compares the output voltage sampling signal with the reference voltage, compares the current waveform with the voltage waveform of power frequency rectification, and comprehensively determines the output pulse width based on the output power (current) to ensure that the output DC voltage is stable at 400V. The output current of the power frequency rectifier, that is, the current on the inductor L or the current on the resistor R18, has a waveform that is approximately full-wave sine. The 50kHz pulse output from pin 16 of N1 is sent to the comparator with hysteresis characteristics of N2:A after pulse width modulation for shaping. The output from pin 1 of N2:A is sent to the complementary emitter composed of V4 and V5 through R23. The follower amplifies, and after being divided by R17 and R16, it is applied to the gate of the VMOS switch V6 to drive it on or off. In fact, V6 is an integrated chip including VMOS tube, boost diode and rectifier bridge.