The requirement for greater voltage levels from low-voltage power sources is a frequent problem in current electronic applications.
Devices can function properly even with low power supplies thanks to a voltage booster circuit, which raises the voltage.
With the help of a PNP transistor 2N2907, an NPN transistor 2N2222, and a variety of passive parts including resistors, capacitor, diodes and inductors, this project presents a voltage booster circuit.
The circuit is made to transform a batteries low input voltage of 3V into a greater output voltage that may be used to power a variety of electronic components.
During the switching operation, the 220µH inductor is essential for storing energy, and the 1N4148 diode makes sure that the output voltage is rectified effectively.
Utilizing a 9V Zener diode aids in stabilizing the voltage and guards against overvoltage situations for downstream components.
Resistors 220k, 100k, and 1k are carefully chosen to establish the transistors working point, guaranteeing the circuit operates at its best.
This voltage booster circuit is a great way to learn about transistor switching, inductive energy storage, and voltage control.
It also shows how simple electrical components may be used in real world applications.
We want to provide a useful resource for electronics enthusiasts and experts alike by investigating the construction, operation and uses of the voltage booster circuit through this project.
Circuit Working:
Parts List:
| Component Type | Specification | Quantity | Wattage |
|---|---|---|---|
| Resistor | 220k | 1 | 1/4 watt |
| Resistor | 100k | 1 | 1/4 watt |
| Resistor | 1k | 1 | 1/4 watt |
| Capacitor Electrolytic | 100µF 25V | 1 | |
| Transistor | PNP 2N2907 | 1 | – |
| Transistor | NPN 2N2222 | 1 | – |
| Inductor | 220µH | 1 | – |
| Diode | 1N4148 | 1 | – |
| Zener Diode | 9V | 1 | – |
| Battery | 3V | 1 | – |
This circuit boosts a 3V DC input to a 9V DC output using an inductor and a transistor.
The inductor and the collector of the second transistor T2 are linked to the base of the first transistor T1.
The collector of T1 is linked to the second transistor T2.
The circuit can function as a whole thanks to this configuration.
The C1 capacitor 100µF at the output filters the oscillating frequency of the booster output.
The inductors strong voltage spikes are handled by a diode D1, and the output voltage is stabilized by a Zener diode.
To smooth out the DC signal, it is a good idea to add a filter capacitor before the Zener diode.
Current passes through the inductor when the power is on, gradually accumulating energy.
When it reaches T1s base, the energy activates it and it becomes completely charged.
Additionally, this powers T2, which activates both transistors and swiftly releases the accumulated energy.
The transistors then shut off since the inductors energy is no longer there.
After that, the inductor begins to charge once more, and the cycle keeps going.
The diode D1 assists in converting the high voltage spikes produced by this rapid charging and discharging into a steady, high DC output voltage.
Formulas:
Several important relationships and formulas are used to comprehend the behavior of a basic transistor-based voltage booster circuit.
The relevant formulas are listed below:
Voltage Gain (Vout/Vin):
Vout = Vin x (R1+R2 / R2)
where
- Vin is the input voltage for 3V
- R1 is the 220k resistor
- R2 is the 100k resistor.
Inductor Voltage (VL):
VL = L x di / dt
where,
- L is the inductance 22µH
- di/dt is the rate of change of current through the inductor.
Zener Regulation:
VZ (Zener Voltage) = 9V
where,
The output voltage is kept at about 9V by the Zener diode.
Capacitor Charging Formula:
VC = Vout x (1−e−t / RC)
where,
- VC is the voltage across the capacitor
- R is the load resistance
- C is the capacitance 100µF
- t is the time constant.
Switching Frequency (f):
f = 1 / T
where,
- T is the time period of one complete charge-discharge cycle of the inductor.
How to Build:
To build a Simple Transistor-Based Voltage Booster Circuit following are the steps to follow for connections:
- Assemble all the components as shown in the above diagram.
- Connect collector pin of transistor T1 2N2907 to GND through resistor R3 1k.
- Connect base pin of transistor T1 between the junction of resistor R1100k and R2 220k
- Connect the junction of the transistor T1 emitter and the 22uH inductor to +3V input.
- Connect the collector pin of transistor T2 2N2222 to one terminal of inductor 22uH and the junction of R1 220k resistor and D1 1N4148 anode.
- Connect base pin of transistor T2 between collector of transistor T1 and resistor R3.
- Connect the emitter of transistor T2 to GND.
- Connect a the cathode of D2 Zener diode with the cathode of D1 diode and connect the anode of D2 with the GND.
- Connect capacitor C1 100uF positive leg to 9V output booster DC and negative leg to GND.
Conclusion:
The booster circuit, which is built on transistors and inductors, efficiently converts a 3V DC input into a 9V DC output.
The circuit effectively charges and discharges the inductor by using a feedback mechanism between the two transistors.
This results in high voltage spikes that are rectified into steady output voltage.
This design demonstrates a workable way to increase voltage in electronic applications and emphasizes the significance of parts like filter capacitors and diodes in guaranteeing a stable power supply.