Лабораторный блок питания из старого телевизора

Introduction

In this tutorial, we will guide you through the process of building a laboratory power supply using parts from an old television. This project is particularly useful for those in need of a reliable and adjustable power source, especially in challenging situations where commercial options are unavailable. We will cover the necessary steps, materials, and safety precautions to create a functional power supply.

Step 1: Gather Materials

To build your laboratory power supply, you will need the following materials:

• An old television (preferably one with a working power supply)
• A multimeter
• Wire cutters and strippers
• Soldering iron and solder
• Heat shrink tubing or electrical tape
• Potentiometers (for voltage adjustment)
• Various connectors (banana plugs, alligator clips, etc.)
• A suitable casing (to house the components)

Tips for Material Selection

• Ensure the television is unplugged before disassembly.
• Look for a TV that has a transformer and rectifiers, as these are key components for voltage regulation.

Step 2: Disassemble the Television

Carefully disassemble the old television to access the power supply components. Follow these steps:

1. Remove the casing: Use a screwdriver to unscrew and remove the outer casing of the TV.
2. Locate the power supply board: Identify the power supply board within the television. This is usually where the AC power is converted to DC voltage.
3. Take note of connections: Before removing any components, take pictures or notes of how everything is connected.

Safety Precautions

• Be cautious of high voltage components, especially capacitors, which can retain charge even after disconnection.
• Use insulated tools to avoid electric shock.

Step 3: Identify Key Components

Once you have access to the power supply board, identify the following components:

• Transformer: Converts voltage levels.
• Diodes: Rectify AC to DC voltage.
• Capacitors: Smooth out fluctuations in the output voltage.
• Potentiometers: Allow for voltage adjustment.

Common Pitfalls

• Do not attempt to work on the circuit while it is powered on.
• Make sure to discharge capacitors safely before handling.

Step 4: Rewire the Power Supply

Rewire the components to create your adjustable power supply. Follow these steps:

1. Disconnect components: Carefully desolder the existing connections from the power supply board.
2. Connect the transformer: Solder the transformer leads to the input side of the power supply.
3. Add diodes: Connect the diodes to the output side to convert AC to DC.
4. Install capacitors: Solder capacitors to filter the output voltage.
5. Add potentiometers: Connect potentiometers to allow for voltage adjustment.

Example Wiring Diagram

[Transformer] -- [Diodes] -- [Capacitors] -- [Potentiometers] -- [Output]

Step 5: Test the Power Supply

Before finalizing the build, it is essential to test the power supply to ensure it operates correctly. Follow these steps:

1. Set up the multimeter: Connect the multimeter probes to the output terminals.
2. Power on the supply: Carefully power on the device.
3. Measure output voltage: Adjust the potentiometers and observe changes in voltage on the multimeter.

Troubleshooting Tips

• If the output voltage is unstable, check all connections for solid solder joints.
• Ensure the components are rated for the voltage levels you are working with.

Step 6: Final Assembly

Once you have confirmed the power supply is functioning correctly, proceed to assemble everything into the casing:

1. Organize wiring: Neatly place all wires and components within the casing.
2. Secure components: Use screws or brackets to secure the power supply board and other components firmly.
3. Close the casing: Finally, close the casing and ensure all parts are safely enclosed.

Conclusion

Congratulations on building your own laboratory power supply! This project not only provides a practical solution for adjustable voltage needs but also enhances your understanding of electronics. For further exploration, consider experimenting with different output voltages and current capabilities. Always prioritize safety when working with electrical components. Happy tinkering!