How to Design Schematic Circuit of Fluorescent Lamp Inverter

 This circuit will light a common fluorescent tube (from 7 to 4O watts) from a 6-

or 12-volt power supply, such as ni-cad cells, D cells, car battery or other

source, without need of a choke or starter. Even the old tubes which no longer

function at all on AC power lines will light when used for this purpose. (Some

of them, though, may be too weak to light when the circuit is powered from 6

or 12 volts.You should experiment beforehand.)

You can use the device as an emergency light, in trailers, signaling, etc.

By powering the fluorescent lamp with a transformer power supply you increase safety factor of an experiment, avoiding dangerous shocks or shorts.

Current drain, typically ranging from 100 to 800 mA, depends on the characteristics of the lamp used, the power supply voltage, and the transformer.

The lamp will brighten according to the drained current. Experiments should

be done with some ditferentransformers and oscillator frequencies to get

better performance out of the circuit.

Basicaly, the circuit is a low-frequency oscillator driving a transformer. High

voltage is obtained from the transformer to'light a fluorescent light.

The trimmer potentiometer allows frequency adjustment to get better performance.

Schematic diagram of the Fluorescent Lamp Inverter is displayedin Figure

1. As you see, the circuit consists of a low-frequency oscillator with a pair of

complementary transistors.

Components layout, using a terminal strip as chassis, is shown in Figure 2,

Components placement is not critical.

Transistor Q2 should be mounted on a large heatsink.Tl is a 6V x 450 mA or

12Y x 450 mA transformer. lf a CT (center-tapped secondary coil) transformer is you should use only two of the three secondary's wires.

Experiments with transformers with secondary currents from 300 to 800 mA

and voltages betweeen 9 and 15V can be made to get better performance.

Warning: The fluorescent lamp is powered with high voltages that can be

dangerous. Take care of the wires' insulations and when handling connections to the device.

Parts List - Simple Fluorescent Lamp Inverter

Q1 - 8C548 - general purpose NPN silicon transistor

Q2 -T,P42 - PNP power transistor

T1 - Transformer: 1 17 VAC; 6V x 450 mA or 12Y x 450 mA

Xl - Fluorescent lamp - see text

P1 - 470,000 ohms - trimmer potentiometer

R1 - 10,000 ohms, 1/4-watt, 5% - resistor

R2 - 1,000 ohms, 114-watl,5% - resistor

C1 - 0.047 uF - metal film caPacitor