Power outage emergency light circuit

(1) Working principle As can be seen from Figure 1-54, the inverter
circuit is an intermittent oscillator fed back by the transformer. R provides the bias
current of VT, G determines the oscillation frequency of the circuit, and C3 is a DC blocking capacitor set to prevent premature blackening of the lamp tube.
    (2) Component selection The entire circuit requires a lot of components. VT can use 3DD15 high-power transistors with p≥80. Use a 1/
4W resistor for R; it is better to use polyester capacitors for G and G. The component values ​​are marked on the diagram. The power transformer can be 10W, 220V/9V.
The pulse transformer is a finished product produced by Shengli Electronics Factory in Anyang City, Henan Province, and the battery can be a 6V, 4Ah battery. VD uses 1N4004 type
or other 2CZ type rectifier diodes, but the current is not less than 1A.
    (3) Production and debugging of inverter components are all soldered on the printed circuit board. When installing, be careful not to weld the wire ends of the pulse transformer incorrectly,
otherwise the circuit will not vibrate and the fluorescent tube will not light up. The transistor needs to be equipped with a heat sink, which can be made of Zmm thick aluminum plate with a size of not less than
30mm × 40mm and holes are drilled according to the location. The welding must be reliable to reduce unnecessary trouble in debugging work. The power supply and rectifier part can
be installed in other wooden or plastic boxes, and then connected to the inverter circuit board with wires.