Tower Led




The tower is composed of acrylic where we were installing LEDs

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Step 1: What We Need

1 Threaded Rod
10 Leds (20 for beter result)
1 capacitor 63V 10uF
2 resistors 10k
IC LM3914N
acrylic sheet 8mm
acrylic sheet 4mm (option for the for the box that contains the circuit)
2k pot
50k pot
100k resistor (option. The resistance value can change it depend on your stereo)
2 diode zener

Other material:

hot glue
pliers long nose
30 nut for the Threaded Rod   (on my project)
sander p100 (for the edge)

Step 2: Schematic

The LM3914 is a ic used to test battery, one day I wanted to make a LED tower and I made some changes to the circuit. Still you can use to test battery 1.5v, 9v and 12v. By changing R3 and R5 by a resistance:
5k for 1.5v
85k for 9v
110k for 12v

Step 3: Cut Acrylic and Wood and Drill It

You can cut the acrylique with a saw or electric saw (not fast you can melt acrylic). drill the acrylique,use drill 5mm for the LEDs and make a hole around 0.5 to 1 cm.

cut your wood to make a stable base to hold the tower. for my project I use a wood 15 cm by 25 cm and 3cm thick

the hardest time, drill the holes for the rod. holes must be in the same place on all acrylic sheets

Step 4: Finiching and Result :)

I used hot glue for leds on the acrylic and cooled with ice to the glue becomes translucent. 
welding the anodes of the LEDs to have a common positive wire
connect all led to the board.
remember: led 10 is connected on pin 1 and the first led is connected on pin 10

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    13 Discussions


    Reply 3 years ago

    Hi Kelvinzhang

    the LM3914N compares the input voltage(from audio pin 5) to an external voltage to light up the right LED here the datasheet for the ic

    hope i can help and sorry for the late


    5 years ago on Introduction

    Is there someway to make this minus the cap? I have all the parts except the capacitor, and am wondering what the purpose of the capacitor is and if it's necessary, or if it can be replaced wiht something else.

    4 replies

    Can't the zener diodes be replaced with just normal diodes? I can't find a reason for them to be zener diodes.


    Reply 5 years ago on Introduction

    you can not replace the zener diodes with normal diodes. I think you can you obtain for cheap on ebay. the zener diode is used to regulate the voltage


    Reply 5 years ago

    hy neutralityy I don't know exactly what the cap does, but its not realy necessary.


    Reply 5 years ago on Introduction

    What are the specs of the zener diodes you used? What wattage and whats the breakaway voltage? Are both diodes identical?

    Great job. Did you have wait till the cat fell asleep before starting your project? I had cats and I am still finding lost project parts or toys (Depends
    on your purrrrspective)

    1 reply
    Finger44Fikjast Scott

    Reply 5 years ago on Introduction

    they take my components as played and lost :). they like to sleep on my worktable and I must find a place to work