Introduction: Simple & Easy to Make Vu Meter or Audio Meter Using LM3915

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In this tutorial i will show you how to make a simple & easy Vu Meter or Audio Meter using LM3915.

The Video Tutorial is also embedded along with this tutorial. In the video tutorial things from the making the circuit till the testing are shown.

Testing begins @4:45

Step 1: Parts List

***Parts List***

1. 10k Pot

2. LM3915

3. Resistor - 1k

4. 3 pin Terminal Block Connector

5. Bright LED's - Green - 4 No's, Red - 4 No's & Blue - 2 No's

6. 5 Pin JST Connectors - 2 No's

7. Male Headers

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***Purchase List or Affiliate Links***

AliExpress
1. 10k Pot - https://goo.gl/NePZUs

2. LM3915 - https://goo.gl/514oxu

3. 3 pin Terminal Block Connector - https://goo.gl/PfAiGt

4. 5 Pin JST Connectors - https://goo.gl/ecxEKQ

5. Male Headers - http://s.click.aliexpress.com/e/YZrJYfm

***Other Required Components***

a. Soldering Equipment - https://goo.gl/H7iwZ1

b. PCB Board - https://goo.gl/iNALh8

c. Wires - https://goo.gl/46PPgv

d. Multi-meter - https://goo.gl/MqWxbq

Step 2: Circuit Diagram & Finished Images

Construct the circuit as shown in the circuit diagram.

Working :

Once the circuit has been completed,

Setting the Vu Meter:

To set the Vu meter, power the circuit with 12V for optimal performance without an input audio signal. Now using the 10k pot adjust such that only the D1 & D10 glows. Once this has been set, connect the Pin 9 to the Vin, if the adjustment is right all the LED'd should glow if not the repeat the adjustment procedure.

Once the setting is done connect the amplifier & audio signal to the Vu meter & enjoy your music

Note: When the audio input is connected & there is no audio played no LED'd should glow. If there is any there must a problem with your circuit connection.

Step 3: Dot & Bar Mode

Mode Selection :

Bar Mode: To select the Bar mode you have to simply connect the Pin 9 of LM3915 to the Vin.

Dot Mode : To select the Dot mode leave the Pin 9 of LM3915 open

Note : While playing audio signal's it is very hard to notice the Bar & Dot Mode. If you want to test the Bar mode & Dot Mode you can do the following

1. If you have a signal generator, then set the signal generator to 1 KHz & pass the signal to the Vu meter

2. You can connect the Vin/+ve to the audio signal input port

For test results you can watch the video attached with this tutorial or Click Here
Testing begins @4:45


Thank You for Reading.
For more such projects you can visit my YouTube Channel by CLICKING HERE

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