Fluorescent lamp dimming circuit three

(3) Fluorescent lamp dimming circuit three
    The circuit is shown in Figure 2-80. This dimmer can dim the 40W fluorescent lamp within the range of 10-40W.
    The phase-shift trigger circuit is composed of a single-junction transistor VT, a resistor Rz, a potentiometer RP and a capacitor C1. By adjusting RP,
the conduction angle of the thyristor Vl can be changed, which also changes the conduction angle of the bidirectional thyristor V2, thereby realizing the adjustment of fluorescent lamps. Light.
    In Figure 2-80, the ballast L is the ballast with the original fluorescent tube; the core of the transformer T is made of ordinary silicon steel sheet with a cross-section
of 19mm×19mm, and the primary is wound with 2860 turns of enameled wire with a diameter of 0.15mm ; the winding of 25V Use
enameled wire with a diameter of O.lmm to wind 660 turns; the 6.3V winding uses a diameter of o. 59mm enameled wire wound with 83 turns.