Imagine all the cool electronic devices you use need clean steady power to work right.
That is what a stable power supply does.
This article shows you how to build a simple power supply using a part called a zener diode.
This kind of supply is good for projects that need a constant 12V and can handle a decent amount of power.
What is a 12V Regulated Power Supply Circuit:
A 12V regulated power supply circuit is an electrical circuit that converts a variable input voltage into a constant controlled output voltage of 12V.
This circuit is often used to power several electronic components and devices that require a constant and limitless 12V DC power source.
The regulation ensures that the output voltage remains uniform even in cases where the input voltage or load conditions changes.
Circuit Working:
Component List:
| Component | Quantity |
|---|---|
| Resistors (all 1/4 watt) | |
| 10Ω 1W | 1 |
| 1k 0.5W | 1 |
| 560Ω 0.5W | 1 |
| Capacitors | |
| Electrolytic 470µF 16V | 1 |
| Electrolytic 100µF 16V | 2 |
| Semiconductors | |
| Bridge Rectifier 1N4007 | 4 |
| Zener Diode 12V 1W | 1 |
| LED Green 3.3V 20mA | 1 |
| Transistor TIP35C | 1 |
| Transformer 0-15V | 1 |
The Zener diode which functions in the Zener breakdown in reverse bias region is the circuits key component.
The transistor Q1 acts as a variable resistor changing its resistance in response to the base current while the Zener diode supplies a reference voltage.
The regulated output voltage (Vout) is calculated using the below mentioned formula:
Vout = Vz − VBE
where:
- Vout is the regulated output voltage.
- Vz is the Zener voltage.
- VBE is the base emitter voltage of the transistor.
The formula is essential for understanding the voltage relationship in circuits using transistors or other circuit parts where the base emitter voltage drops and VBE affects the output voltage Vout.
It is essential to know about circuit design and analysis particularly in the situations where accurate voltage levels are required
Advantages and Disadvantages:
Advantages:
- Simple and cost effective voltage regulation method.
- Stable output voltage.
- Suitable for high current draw applications.
Disadvantages:
- Limited to low to medium power applications.
- Efficiency may be lower compared to other voltage regulation methods.
How to Build:
Follow the below mentioned construction steps for building a 12V Regulated Power Supply Circuit:
Begin using a step down transformer to get an AC input of at least 15V.
Use a bridge rectifier module or four 1N4007 diodes arranged in a bridge configuration to convert the AC supply to DC.
A capacitor C1 is then used to filter the DC supply and smooth out the voltage.
To show that the power source is present, an LED might be added.
Connect resistor R3 and capacitor C2 in series between the positive and negative supply lines to supply transistor Q1 with the VBC supply.
A reverse biased 12V Zener diode ZD1 is connected to the base terminal of the transistor Q1.
The regulated output voltage is triggered by the Zener breakdown at the base of the transistor which is controlled by ZD1.
Different output voltage levels are achieved to meet the needs of different applications by adjusting the Zener diode rating.
Components Functions:
Zener Diode ZD1
- Provides the reference voltage Vz for the circuit.
- Operates in the Zener breakdown region.
- Acts as a key element for stable voltage regulation.
Transistor Q1 – TIP35C
- NPN bipolar junction transistor BJT.
- Designed for general purpose amplifier and switching applications.
- Low power dissipation and high current capability.
- Suitable for medium power applications.
- Comes in a TO220 plastic package for efficient heat dissipation and ease of handling.
Conclusion
The best and most affordable way to achieve constant voltage regulation in electronics is the Zener Diode based 12V Regulated Power Supply Circuit.
You can modify the circuit to satisfy your unique voltage needs by knowing the basic principles and to follow the building guide of the circuit.
To ensure the need of desired voltage and current handling capacity the right Zener diode and transistor parts should be selected.
This circuit is suitable in a variety of applications more demanding projects should come into account with its limitations in terms of power production and efficiency.
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