Simple LED Backlit Sign

In this Instructable, I will show you how to build a very simple but nice looking LED backlit sign.

I built the project only with things i had lying around my electronic shop so the materials i am using are not the appropriate ones but the final product ended up pretty well.

Things You'll Need

Here's a list of the things you'll need.

Some corrugated cardboard

5x 5mm Straw hat warm white LED's.

6x 220 Ohm Resistors.

1x 5mm Red LED or any colour you like.

1x 1000µF, 6.3V or more electrolytic capacitor.

1x Switch

1x A tuna fish can or a top of a small can.

Some long section of electrical wire to connect the sign and switch to the power adapter.

Red, green, yellow or blue electrical tape. (Depending on what colour you want the letters/image to appear.)

Rear sheet of a flat screen monitor (A piece of tar paper would be better)

Diffusing sheet from a flat screen monitor (A clear plastic sheet would work as well)

Aluminium tape (aluminium foil would also work)

Now, let the project begin!

Choose a Template

For the template you are free to do whatever you want, you can design one or find one on the internet, Just make sure you don't take a template that is too complicated because you'll have a hard time cutting it out later on. Don't worry about the colour of the template since we will only use it to know where to cut the letters or image.

Print, Cut, Be Patient and Cut the Letters Out.

First, start by printing your desired template and cutting all around the edge of it, Now tape it to an old rear plastic sheet of a flat screen monitor or a piece of tar paper and cut trough the two with a small utility knife to get an exact copy of the template on the plastic sheet/tar paper.

Warning: Utility knifes are very sharp and can be dangerous if misused! Be careful when using them.

Build the Frame

To build the frame, cut six piece of corrugated cardboard the form of your template, then with a small utility knife cut the inside on five of them leaving 3/4" all around, Once you're done glue the five cardboard frame together with hot glue only in the four corner so you'll be able to slide the LED's in the frame later on.

Leave the sixth one the way it is to use as the back cover.

improvise a Colorized Light Diffuser

I didn't had any red plastic sheet so this is the way I have done it.

Take a diffusing sheet from an old flat screen monitor or clear plastic sheet and tape some Red, Yellow, Green or blue electrical tape by doing your best not to leave gaps or overlapping on it to get an even backlit.

Glue the Colorized Diffuser Behind Your Plastic/tar Paper Sign

Once you're done with your colourized diffuser, glue it behind your plastic sheet/tar paper sign, I used hot glue but a glue that takes more time to dry would be better because you will have more time to work with it, now you can glue the inner parts of the letters/image and let it dry.

Glue Your Finished Sign to the Frame

Glue the frame to your finished sign with hot glue and you're ready to start building the circuit.

Solder the LED's to Current Limiting Resistors

Start by cutting the anodes (+) of the 5mm straw hat warm white LED's leaving about 1/4", Then cut the leads on one side of the 220 Ohm resistors leaving the same length than the LED's anodes And solder them together.

Now you have current protected LED's that can be safely operated at 5 Volts.

Wire Up the LED's

Wire all the LED's in parallel with the right length of wire to place them where you want them, Connect a wire long enough to reach the switch and Insulate all the connections with electrical tape.

Install the LED's in the Frame

Now take the wired LED's and insert them in the frame making sure that the wires are not coming out and that everything is tight.

Install the Reflecting Aluninium Tape

now install the aluminium tape or foil in the inside of the frame leaving the LED's uncovered with about 1/4 inch of space around them to reduce the risk of creating a short circuit.

Then take the back panel and tape one surface with aluminium tape or aluminium foil and glue.

Now you can close the back, test it with a 5V power source and it should work.

If noting happens, make sure that the polarity of your power source is right.

Build the Swich.

Start by cutting a can keeping about 1'' from the top or use a tuna fish can if you have one.

Mark the size of the hole for the switch on the top and with the help of a flat screw driver and a hammer, cut through the can like a with a wood chisel and insert the switch. Drill a hole for the indicator LED and connect everything together (look at pictures and circuit diagram for reference)