20 Watt Fluorescent Tube Emergency Light

This simple 20 watt home emergency tube light circuit uses very few components yet is able to produce a reasonable amount of light.

The components used are very common and can be easily procured from the local electronic retailer.

The idea is simple, the secondary winding of Tr1 and T1 along with the associated components forms a high frequency oscillator circuit.

How the Circuits Works

This oscillations forces an AC in the secondary winding of the transformer which is further induced into the primary of the transformer and stepped up to the corresponding rated value ofthe transformer.

The transformer used is an ordinary 12-0-12 volt 1Amp rated, it can be retrieved from any old, junk power supply unit that might be lying in your electronic junk box.

The transistor also is an ordinary type, here a 2N6101 is shown, but any other similar type will do. You may try a 2N3055 transistor or even a D1351 in place of the specified one.

The 2k5 preset is used for adjusting the frequency of the circuit which in turn affects the brightness of the connected tube.

The preset must be carefully optimized for obtaining maximum brightness on the tube and yet keeping the consumption on the relatively lower side.

The 0.47uF capacitor is also introduced for enhancing the output from the tube light, you may other nearby values for improving the overall brightness.

The battery can be a 12V, 7 AH battery which should last many hours.

However you cannot expect full striking brightness from this circuit. When I tested this circuit, I could never bring the tube light to its actual specified striking brightness.

The following diagram shows how to make a simple 20 watt fluorescent tube, emergency light circuit.

Circuit Diagram Diagram

20 watt fluorescent tube, emergency light circuit.

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Swagatam said…
no, i think it won't work with a mosfet
Nasar Tauheed said…
sir,will this inverter charge the battery?
Nasar Tauheed said…
sir,will this inverter charge the battery??
Swagatam said…
variable resistor
Nasar Tauheed said…
Is preset necessary for this circuit?
Swagatam said…
it's for adjusting the brightness of the tube to the optimal point
kamlesh_sexy said…
Hi friend,
Thanks again for this circuit.
I want circuit so it will run 18w tube(2ft tube) with the power of 3v 2A or 6v 2A battery, i have small transformer 6-0-6 500ma , but i dont want to use big one..(like if 1A transformer bigger then 500ma), if any changes i can make from your above circuit so please tell me, or which parts i have to replace??? i will replace the parts from the circuit you showing above.
Thanks in advance....
Swagatam said…
Hi Kamlesh,

the above shown circuit is not very efficient and will not illuminate the tube with full brightness....you can try the following instead:


Good evening sir!
can we get 40 watt flour.light by fitting two of these inverter circuit?if yes how to connect it each other?
Swagatam said…
you can do it simply by using a higher rated transformer, no need of two units.

but the illumination will be always half due to a half wave conduction in the trafo

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