power factor correction apparatus of airfield light fed constant current

摘要

The present invention relates to a power factor correction drive of the air equalization receiving a constant current, constant input from group a is a constant current and a rectifier (CR) receiving through the transformer for rectifying a DC voltage; The rectifier triac (T1) for switching the input voltage (Vi) output from the (CR) and; And a pair of zener diodes (ZD1, ZD2) connected to each other such that opposed to the triac (T1) is in a conductive state by applying a trigger voltage to the gate terminal of the triac (T1) according to the input voltage (Vi); The triac (T1) and a pair of parallel connected FET are connected to each other contrary (Q1, Q2) and; And switching the driving section 10 to switch to a pair of the FET (Q1, Q2), the PWM signal; The rectifier (CR) input from the input voltage (Vi) the partial pressure of the voltage-dividing resistors (R2, R9) and; The input inputted in the rectifier voltage-dividing resistor (CR) by detecting the voltage at the common connection terminal of the (R2, R9) voltage (Vi) of the pair generates the PWM signal falls below the reference voltage design (VR) FET ( Q1, Q2) and a control unit 20 for controlling so as to switch; The rectifier (CR) converting an input voltage (Vi) at the input to the constant voltage to the voltage regulator is composed of (U1) and outputting to the LED to operate the triac to control the input voltage, instead of by switching the triac pair of FET it is possible to improve the power factor constant current than be bypassed. ;