9v dc transformerless power supply circuit diagram

 9V DC Transformerless Power Supply Circuit diagram 

Introduction

Power supplies are essential components in the world of electronics, providing a stable source of energy to run our devices. In many cases, we require a compact and cost-effective power supply that can deliver a specific voltage, such as 9V DC. One popular solution is a transformerless power supply circuit, which eliminates the need for a bulky and expensive transformer. In this blog post, we'll explore a simple yet efficient 9V DC transformerless power supply circuit diagram that you can easily build for your electronics projects.

Why Use a Transformerless Power Supply?

Transformerless power supplies are becoming increasingly popular for several reasons

1. Cost-Effective: Transformerless designs require fewer components compared to traditional transformer-based power supplies, making them more cost-effective.

2. Compact Size: They are significantly smaller and lighter, making them ideal for applications where space is limited.

3. Efficiency: Transformerless supplies can be highly efficient if designed correctly.

4. Reduced Heat Dissipation: With fewer components, there is less heat generated during operation.

5. Lower Weight: This is especially important for portable and battery-operated devices.

Let's dive into the circuit diagram and see how to build a 9V DC transformerless power supply.

Components You'll Need:

1. AC Voltage Source: Typically, this is your mains power supply (110V or 220V AC, depending on your region).

2. Diode Bridge (1N4007): Converts AC to pulsating DC.

3. Filter Capacitor (100uF, 25V): Smooths the pulsating DC to reduce ripple.

4. Voltage Dropping Capacitor (0.1uF, 250V): Provides further filtration and voltage division.

5. Zener Diode (9V, 1W): Regulates the voltage to 9V DC.

6. Resistor (10k ohms): Limits the current through the Zener diode.

7. LED (Optional): Indicates when the power supply is active.

Circuit Diagram:

Building the Circuit:

1. Safety First: Ensure you are well-versed in working with mains voltage. Always disconnect the power source when working on the circuit.

2. Diode Bridge: Connect the AC voltage source to the diode bridge, ensuring correct polarity.

3. Filter Capacitor: Connect the positive and negative terminals of the diode bridge to the filter capacitor.

4. Voltage Dropping Capacitor: Connect the positive terminal of the filter capacitor to the anode (positive) of the Zener diode. Connect the cathode (negative) of the Zener diode to the ground (negative) side of the filter capacitor.

5. Resistor and LED: If using an LED for indication, connect it in parallel with a resistor between the cathode of the Zener diode and ground.

6. Output: The output of the circuit is taken from the anode of the Zener diode and the ground. This will give you a stable 9V DC output.

Testing:

After assembling the circuit, carefully apply power to it. Measure the output voltage to ensure it is close to 9V DC. The LED, if used, should light up, indicating the power supply is active.

Conclusion:

A 9V DC transformerless power supply can be a convenient solution for various electronics projects where space and cost constraints are essential considerations. However, it's crucial to exercise caution when working with mains voltage and ensure your circuit is correctly assembled to provide a stable and safe power source for your devices. With the right components and proper assembly, you can create a reliable 9V DC power supply for your electronics projects.