Low Profile LED Shelf Lighting

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Introduction: Low Profile LED Shelf Lighting

Add nearly hidden lighting to shelves, cabinets and desk cubbies. It's great for hard to see areas, accent lighting and places where power outlets are not available.

Step 1: What You Need

-12 to 16 high output (8000 or higher MCD) white LEDs per shelf/cabinet

-Small on/off switch, either push button or toggle switch

-3 AA or AAA battery holder or 3.5 Volt DC power supply

-Wire

-Solder and soldering iron/gun

-Dremel or other grinding tool

-Pliers

-Hot glue gun

Step 2: Grind the LEDs

Use the pliers to clamp the LEDs by the wires and grind down the lens part of the LED. Keep grinding it down until the side profile of the LED is square shaped - about as tall as it is wide.

The reasons for grinding the LEDs is both to make them lower profile, and also to frost the top surface so that the light output is diffused.

After grinding bend all the wires 90 degrees at the base of the LEDs. Bend all the wires the same way - polarity matters on LEDs. This will allow all the LEDs to be soldered together into one chain.

Step 3: Solder the LEDs Together

Simply solder the ends of the pins from one LED to the base of the next LED, and repeat until you have one straight chain using all the LEDs. Typically, 12 or 16 are enough for each shelf or cabinet. Make sure all the LEDs have the same polarity (longer pin on one side, shorter on the other.)

After soldering, check if the chain is straight - resolder the crooked links until the LEDs form a straight line.

Test the string with some button cell batteries or with the 3 AA/AAA battery pack.

Step 4: Add the Switch and Power Supply

Find a convenient place where you will be placing the power supply, power switch and the LEDs themselves within your cabinet and measure the amount of wire you will be needing.

Solder the wires to the LEDs. Solder the negative wire straight to the battery pack or power supply and solder the positive wires to the power switch.

Step 5: Install Lights in Cabinet

Use small amounts of hot glue to attach the LEDs, wires, power switch and battery pack to the cabinet and you're done!

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    user

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    50 Comments

    user

    Excuse my poor knowledge in electronics, im just starting out.. but, to my understandment now, each LED is about 3.5volts and you used 16 LEDS which would be about 56 volts and for you power supply you used 3 1.5volt AAA batteries which is exactly 4.5 Volts in power. which is no where near 56.. So my question how did you power 16 leds with just 4.5volts of power? ive been wanting to wire my leds in a line like this forever, but just couldnt figure out the volts/power thing if anyone can help that would be great!! thnx in advance!

    If all the LEDs are wired in series (the positive pin of LED1 is wired to the negative pin of LED2, the positive pin of LED2 wired to negative of LED3, etc....) then, yes, it would require 56 or so volts. If all the LEDs are wired in parallel (all the negative pins wired together, and all the positive pins together) it requires 3.6 volts - same as using just one LED.

    just want to add to this that in series connection there is a voltage drop on each component while in parallel connection there is a current drop that the longer you put a component the current supplied to it will be lessen.

    Im new to this too, hence the mind blown picture i use. Im learning new things every day on this website and you my friend have just taught me something else :) thank you

    In this project are the LEDs connected in series or parallel?

    These are connected in parallel

    how long does it last on those batteries?

    user

    thnx for the reply!! but one last thing, if say using 4.5 volts to power 16 leds in a parrellel... do they all recieve equal amount of good power, or are they dimmer then they should be since sharing so little power

    dimmer, but it works. i think this is a good idea, i wonder whare i can put something like this... did you think of using surface mount LEDs?

    LED's are non-linear devices. As you apply more voltage the current increases more than 1 to 1. LED's are specified at a particular forward voltage and current. a typical white or blue LED may be spec'd at 3.3V @ 20mA. If you apply a regulated 3.3V across a white LED the draw will be 20mA typical. You can get by not using a resitor to limit current. If you put 2 matched LED's in parallel the total draw will be 40mA. This equals a power of 0.132W. If you put these LED's in series and apply 6.6V the total draw is 20mA. This still equals 0.132W (TANSTAAFL). If you apply 5V to a typical 3.3V LED the current will go up to hundreds of mA and exceed the max power rating very quickly and burn out (remember non-linear). In this case you want put a resistor in series. The correct value would be the voltage drop (5V-3.3V=1.7V) divided by the current (0.02A or 20mA) which is 85 ohms. Different LED colors have different voltage ratings at 20mA. Red is 1.8V, green, amber and yellow is 2.1 to 2.5V and white and blue are 3.3V. If you test a batch of LED's with a constant current source (20mA) you would find some variation in voltage (3.0 to 3.5V)so if you apply a constant voltage (3.3V) across this same batch you will see some variation in brightness because brightness depends on current. To run LED's off of AC source you must rectify the AC(117Vrms*1.414=165.4Vpeak)and series wire 50 white LED's (165.4/3.3). If you use fewer LED's you have to calculate the proper resitor (don't forget to use the right power rating P=V*I). Rectified AC may cause a flicker that some people will notice. Using full wave rectification and a high voltage (300V) filter capacitor will help minimize this.