How to Make Transistor VU Meter DIY Homemade

Introduction

A VU meter, short for volume unit meter, is a device used to measure the intensity of audio signals. It is commonly found in audio equipment such as amplifiers, mixing consoles, and audio interfaces. While there are various types of VU meters available in the market, making your own transistor VU meter can be a rewarding DIY project. In this article, we will discuss how to make a transistor VU meter DIY using BC547 and BC557 transistors, two commonly used transistors in audio circuits.

BC547 Transistor:

The BC547 transistor is a general-purpose NPN transistor that is widely used in audio and small signal amplification applications. It features a low noise figure, making it ideal for audio amplifiers where minimizing unwanted noise is crucial. The BC547 has a maximum collector current of 100mA, making it suitable for low to medium power applications. This transistor is commonly available in TO-92 packaging and is easily recognizable by its three leads – emitter, base, and collector.

BC557 Transistor:

On the other hand, the BC557 transistor is a complementary PNP transistor to the BC547. It shares similar characteristics with the BC547 but with opposite polarities. Like the BC547, the BC557 is widely used in audio circuits due to its low noise figure. It has a maximum collector current of 100mA, making it suitable for low to medium power applications as well. The BC557 is also available in TO-92 packaging.

Circuit Diagram of Transistor VU Meter DIY

This project can be designed using a few basic components. The circuit diagram of this project is shown below.

How to Make Transistor VU Meter Circuit Diagram — **Transistor VU Meter Circuit Diagram**

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Components List of Transistor VU Meter DIY

Following is the list of all components used in this project:

6X LEDs
6X BC547 TRANSISTORS
1X BC557 TRANSISTOR
7X 1N4007 DIODES
7X 10K RESISTORS
6X 470 OHM RESISTOR
1X 100uF CAPACITOR
1X 1uF CAPACITOR
VERO BOARD
JUMPER WIRES

Building a Transistor VU Meter:

Now that we understand the basics of BC547 and BC557 transistors, let’s move on to building a transistor VU meter DIY. To build the transistor VU meter, you will need the components as listed above in the Components List section.

Now, let’s dive into the steps to build the transistor VU meter:

Begin by assembling the components on the breadboard or PCB. Place the 6 pieces of BC547 transistors and one BC557 transistors in a row, alternating between the two types.
Connect the pin-3 of each BC547 transistor to the ground. This will act as the reference point for the VU meter.
Connect a 6 pieces of 10k-ohm resistor to the pin-2 of each BC547 transistor. Also connection 6 pieces of 1n4007 diodes in between the other side of all 10k resisters in series as shown in the circuit diagram, Be careful the to check the polarity of the diode according to the circuit diagram.
Connect a 10k-ohm resistor and the positive side of 100uf capacitor to the pin-1 of BC557 transistor. Also connect the negative side of 100uf capacitor along with the other side of 10k resister to the ground.
Connect the pin-1 of each BC547 transistor to the LED’s anode.
Connect the cathode of each LED to the positive +5v through a current-limiting resistor 470 ohm.
Connection pin-3 of BC557 transistor to positive +5v.
Also connection a 1n4007 diode from +5v to pin-2 of BC557 transistor with the exact polarity as shown in the circuit diagram.
Connect a 1uf capacitor’s positive side to pin-2 of BC557 transistor and the other side will be used for input signal.
Connect the 470uF capacitor as desired, in parallel to the power supply to filter any noise coming from the input signal.

Once you have assembled the circuit, you can connect the power source to provide the necessary voltage.

Conclusion of Transistor VU Meter DIY

In conclusion, making a transistor VU meter DIY using BC547 and BC557 transistors is a rewarding DIY project. These transistors are widely available and offer excellent performance in audio applications. Building your own VU meter not only enhances your understanding of audio circuits but also allows you to customize the design according to your preferences. Remember, proper wiring connections are crucial for the circuit to function correctly, so make sure to follow a schematic or consult a guide for the appropriate wiring connections.

More projects, You may like:

For more project and circuit diagrams, you can go through the Schematics in the main menu where you can find many interesting projects and circuit diagrams like audio amplifier circuits, voltage booster circuit, battery charger circuit and timer circuits etc., which are all beginner circuit projects. Feel free to check them out!

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