Voltage regulators is very important in power supply as they keep voltage steady and even if input voltage changes or load changes.
Also, this circuit give steady 12V output with max 3A current and 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 and it is good for power amplifiers, battery chargers and vehicle electronics.
Circuit Working:
Parts List:
| Components | Values | 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 |
To begin with, this circuit control strong 12V output using Q1 power transistor and 12V Zener diode D3 keep voltage steady.
First, the transformer change 230V AC to 15V AC and then 5A bridge rectifier D1 change AC to DC; then big capacitor C1 smooth voltage and remove bumps.
After that, diode D2 1N4007 stop reverse current from Zener and make circuit safe and stable and Zener diode D3 give steady 12V reference voltage and this control transistor Q1 base through 680Ω resistor R1.
Hence, if voltage goes above 12V then transistor work to keep output steady and 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:
- First, gather all parts as from circuit diagram.
- Next, 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 and then connect Q1 collector to one end of resistor R1.
- After that, connect transformer primary to 230V AC mains and then connect transformer secondary 15V AC to two ends of bridge rectifier.
- Also, connect one bridge rectifier terminal to positive side of capacitor C1 and connect other bridge rectifier terminal to ground GND.
- Finally, connect capacitor C2 between Q1 emitter Vout and ground GND.
Conclusion:
Overall, this High Current 12V Voltage Regulator Circuit using Transistor gives steady 12V output and can give high current.
Furthermore, 2N3055 transistor keep voltage stable and Zener diode keep voltage accurate; also it is good circuit for projects which need strong, steady and reliable power.