Voltage regulators is very important in power supply.
They keep voltage steady and even if input voltage changes or load changes.
This circuit give steady 12V output with max 3A current.
If current need more than 3A then it still works good for regulation.
High Current 12V Voltage Regulator Circuit using Transistor give steady 12V and handles high current.
It is good for power amplifiers, battery chargers and vehicle electronics.
Circuit Working:
Parts List:
| Component Type | Specification | Quantity |
|---|---|---|
| Resistor | 680Ω 1/4 watt | 1 |
| Capacitors | Electrolytic 4700µF 25V | 1 |
| Ceramic 0.01µF | 1 | |
| Semiconductors | Transistor 2N3055 | 1 |
| Bridge Rectifier 6A4 5A | 4 | |
| Zener Diode 12V | 1 | |
| Diode 1N4007 | 1 | |
| Transformer 230V primary 15V/5A secondary | 1 |
This circuit control strong 12V output using Q1 power transistor.
12V Zener diode D3 keep voltage steady.
First the transformer change 230V AC to 15V AC.
Then 5A bridge rectifier D1 change AC to DC.
Big capacitor C1 smooth voltage and remove bumps.
Diode D2 1N4007 stop reverse current from Zener and make circuit safe and stable.
Zener diode D3 give steady 12V reference voltage.
This control transistor Q1 base through 680Ω resistor R1.
If voltage goes above 12V then transistor work to keep output steady.
Also 0.01µF capacitor C2 filter noise for more stable output.
Formulas with Calculations:
Transformer Output Voltage:
Transformer gives 15V AC to have enough for regulation.
After rectifier:
VDC = VAC × 1.414 (√2 for peak voltage)
VDC = 15V × 1.414 = 21.21V DC
This 21V DC goes to regulator circuit.
Transistor Base Current:
Output current need 5A.
Transistor gain (β) = 20
Base current IB = IC ÷ β
IB = 5A ÷ 20 = 0.25A
Resistor R1 680Ω control base current for stable work.
How to Build:
To build a High Current 12V Voltage Regulator Circuit using Transistor follow the steps mentioned below:
- Gather all parts as from circuit diagram.
- Connect Q1 transistor base to point where resistor R1, D2 diode anode and D3 Zener diode cathode meet and also to ground GND.
- Connect Q1 emitter to output voltage Vout.
- Connect Q1 collector to one end of resistor R1.
- Connect transformer primary to 230V AC mains.
- Connect transformer secondary 15V AC to two ends of bridge rectifier.
- Connect one bridge rectifier terminal to positive side of capacitor C1.
- Connect other bridge rectifier terminal to ground GND.
- Connect capacitor C2 between Q1 emitter Vout and ground GND.
Conclusion:
This High Current 12V Voltage Regulator Circuit using Transistor gives steady 12V output and can give high current.
2N3055 transistor keep voltage stable.
Zener diode keep voltage accurate.
It is good circuit for projects which need strong, steady and reliable power.
References:
Using Linear Voltage regulators in parallel for a high current load