| 摘要 |
A current driven toroid-free feedback type ballast comprising a filter and rectifier circuit, a switch and resonant circuit and a lamp load including capacitors, wherein th e filter and rectifier circuit is coupled to input ends of the switch and resonant circuit with its output ends; the switch and resonant circuit is coupled to the lamp load with its output ends and comprising: a trigger circuit comprised of resistors R1, R2, a capacitor C3, a diode D5 an d a trigger diode DB3; a half bridge circuit comprised of transistors Q1, Q2 and resistors; an d a three winding transformer T comprised of primary winding T3 and two secondary windings T1, T2.; In the current driven toroid-free feedback type ballast of the present invention, t he switch and resonant circuit employs a half bridge circuit of transistors together with the transformer to effect driving feedback such that the ballast possess the advantage of toroi d- free, which leads to enhanced liability of the lamp load, simplified circuit configuration and manufacturing process whereby to facilitate the miniaturization of electronic ballasts.
|
