12V Battery Powered Fluorescent Lamp Driver Circuit

A fluorescent lamp needs a high voltage alternating current to start glowing and keep shining.

The circuit here is 12V Battery Powered Fluorescent Lamp Driver Circuit.

This circuit cleverly changes a low voltage direct current from a battery into a high voltage alternating current, which helps the fluorescent tube work.

It is really useful for battery powered devices and emergency lights.

The circuit includes an oscillator a MOSFET switch and a step-up transformer and they all work together to power the fluorescent lamp.

Circuit Working:

Parts List:

In this article 12V lead acid battery is used to power the circuit.

The main part of this circuit is the IC 555 integrated circuit, which is a low power version of the popular 555 timer IC.

It is set up to work as an astable multivibrator which means it creates a square wave signal.

This signal is used to control a MOSFET specifically the IRF510 model.

The MOSFET acts like a switch turning on and off quickly which powers the primary winding of the transformer.

The transformer is really important because it increases the voltage providing the high voltage alternating current needed to light up the fluorescent tube.

To set up transformer you need to use a 1Amp, 220V to 12V step down transformer in an inverted way.

This means you should connect the 12V winding to the MOSFET side and the 220V winding to the fluorescent lamp side.

Also, capacitor C4 helps keep the high voltage pulses steady making sure the lamp keeps working properly.

Formulas with Calculations:

The formulas and calculations for 12V Battery Powered Fluorescent Lamp Driver Circuit is mentioned below:

Frequency of oscillation:

Frequency of oscillation F for the IC 555 Timer in astable mode:

F = 1.44 / ((R1 + 2R2) * C2)

where,

R1 = 1kΩ = 1000Ω

R2 = 2.7kΩ = 2700Ω

C2 = 0.01µF = 10^-8 F

Calculation:

F = 1.44 / ((1000 + 2 × 2700) × 10^-8)

F = 1.44 / (6400 × 10^-8)

F = 1.44 / 0.000064

F = 22.5 kHz

MOSFET Switching Time:

T(on) = R1 * C2

T(off) = (R1 + 2R2) * C2

Calculation:

T(on) = 1000 × 10^-8 = 0.00001 sec = 10µs

T(off) = 6400 × 10^-8 = 0.000064 sec = 64µs

Output Voltage of Transformer (Approximate):

Vout = Vin * (Nsecondary / Nprimary)

where,

• Vin = 12V DC input
• Assume Nsecondary / Nprimary = 20 (for step-up ratio)

Calculation:

Vout = 12V × 20 = 240V AC (approximate)

How to Build:

To build a 12V Battery Powered Fluorescent Lamp Driver Circuit following steps are required to follow the connecting the circuit:

• Gather all the components required as mentioned in the above circuit diagram
• Connect pin 1 of IC1 555 to GND
• Connect pin 2 to pin 6 of IC1
• Connect capacitor C2 from pin 2 and GND.
• Connect pin 3 of IC1 to GATE pin of MOSFET Q1
• Connect pin 4 and pin 8 of IC1 to +12V positive supply of the circuit
• Connect resistor R2 between pin 6 and pin 7 of IC1.
• Connect resistor R1 from pin 7 of IC1 tp positive supply.
• Connect positive side of capacitor C1 to positive supply of the circuit and negative of capacitor connect to GND.
• Connect one end of capacitor C3 to positive supply and other end connect to DRAIN pin of MOSFET Q1
• Connect SOURCE pin of MOSFET Q1 to GND.
• Connect the primary end of transformer one end to poistive supply of circuit and other primary end connect between capacitor C3 and DRAIN pin of MOSFET Q1.
• Connect the secondary one end of transformer to florescent tube and other end of secondary of transformer connect to other end of florescent tube through capacitor C4

Conclusion:

This 12V Battery Powered Fluorescent Lamp Driver Circuit is a great way to run a fluorescent tube with a low voltage DC power source.

It is perfect for things like battery operated lights emergency lighting and saving energy.

You can tweak the frequency parts R1, R2 and C2 to make the circuit work best with different sizes of tubes.

Using a MOSFET helps to convert power efficiently so there are very few losses.

References:

Battery powered electronic ballast for fluorescent lamp with frequency control