Tip31 + LEDs Glowing Tube




Introduction: Tip31 + LEDs Glowing Tube

A very cool glowing tube that will beat to your music. A simple build with a very cool end product. The second photo is a simplified mini version of this project. Use it as a reference or ignore it completely. It sure helped me with this build.

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Step 1: Components

1     tip31 transistor
10  3mm blue LEDs
1    3.5mm audio jack
1    9 volt battery
1    9 volt power jack
2 lead wire
soldering iron
wire strippers
hot glue gun
600 sand paper

Step 2: Tip31 Basic Circuit

The circuit itself is very simple. A battery runs through a transistor to LEDs with an audio signal inputted. The tip31 transistor takes the power from the battery and holds it. Then the transistor which also has the 3.5mm audio jack connected waits for the signal to allow the charge to pass through the LEDs. The LEDs can either be ran through a parallel circuit, or a series. For this project I used a parallel circuit.

Step 3: Construction of the Housing

I decided to use a clear Plexiglas sheet that was cut on the table saw to be 4" wide and 24" long. With each piece cut, I sanded the surfaces with a 600 grit sand paper to give it the foggy look which would displace the light from the LEDs. I then proceeded to hot glue these pieces together to form a triangle.

Step 4: Installing the LEDs

One in the middle, and 6" from each side is one LED. There are also 2 LEDs on each end. As you can see in the photo I put them on both sides of the panel to get the most luminescence. All 10 LEDs were used to make this glow as bright as possible. 

Step 5: Components in a Housing

All of the pieces of the simple circuit were put into a small project box for neatness and safe keeping. 

Step 6: Final Product

This is the final test of the project. I played the song Lights by Ellie Goulding. Much brighter in person

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    3 Discussions


    3 years ago

    Why didnt u use any resistors


    6 years ago on Introduction

    This is really cool! say if i wanted to make one with more LED's would i have to increase the voltage? or is current more the issue? bear in mind i'm thinking 30+ LED's


    Reply 4 years ago on Introduction

    i know this is 2 years too late but it might help someone else. It depends on whether you are running them in parallel or series. if parallel, as long as your source voltage is higher than your forward voltage, you're fine. Most 5mm LEDs run on around 3.6 v at 30mA and a standard phone charger puts out up to 5v at 1000mA, so you could run about 30 LEDs with a standard phone charger, you could use more LEDs if you limit the current to say 25 or 20 mA using a higher ohm resistor.

    (input voltage - LED fwd voltage) / LED operating current = resistor value

    (input voltage - LED fwd voltage) * LED operating current = resistor power rating