Under Kitchen Cabinet LED Strip Lights for Under $30.00!




I lit up my kitchen counter top with modern LED lighting for just over $20.00. My exact cost was $20.62 ($7.63 + $12.99) because I had everything else laying around. You can do yours for less than $30.00 depending on what donor parts you already have laying around!

Here is what I used:

12 VDC 2 Amp Universal Power Supply - $7.63 from Amazon Prime. http://www.amazon.com/gp/product/B002FH54L6/ref=oh...

Super bright 5 meter (over 15 feet!) LED strip light - $12.99 from Amazon Prime. http://www.amazon.com/gp/product/B00JQV6NNC/ref=oh...

Donor power cord from a desk lamp I was not using

Rotary power switch from the same cord, relocated to close to the plug end. If your cord does not have a rotary power switch, they are $5.24 from Amazon Prime. http://www.amazon.com/Leviton-423-3-6A-125V-3A-125...

Fine gauge red and black wire - I used some 24 gauge wire I had laying around.

You will also need a soldering iron and some electronics solder, not plumbers solder. Plumbers solder and plumbers solder flux both contain acid that will eat through wires!

Step 1: Scrounge a Used Power Cord From a Desk Lamp

I scrounged a power cord and rotary power switch from a desk lamp I was never going to use again. Problem was, the switch was on the lamp end of the cord and I wanted it near the plug, so I cut the plug off short of the power switch and removed & relocated the switch.

Step 2: Prepare the Power Cord for the Rotary Switch

Power cords with 2 blade plugs on the end contain two wires. To install a rotary power switch you need to first remove a short section of one of the wires.

Start by cutting half way through the cord in two close places then cut out the piece between.

Next you need to separate the two wires a little. Don't remove any insulation.

Step 3: Assemble the Rotary Power Switch to the Power Cord

Remove the center screw and separate the two halves.

Lay the wires in the non-switch half. You can see from the second picture how the complete wire routes around & past the center screw while the wire with the section missing ends short of the screw.

Then assemble the two switch halves and assemble & tighten the center screw.

Step 4: Measure Your Power Cord Length

Measure from the outlet you will plug into to where the power supply will be mounted.

The cut off the excess power cord. If you aren't sure measure again before you cut.

Just remember, don't plug the power cord in yet!!!!

Step 5: Prepare the End of the Power Cord

Make sure the power plug is not plugged in first!!!

Before the end of the power cord can be attached to the power supply the end has to be split and stripped. The pictures show step by step.

Step 6: Wire AC Power to the Power Supply

The power supply I bought is not that large. It will likely fit in the palm of your hand.

Look at the end and you'll see a set of screws with the following labels.

L Incoming AC Power

N Incoming AC Power

V1- Minus 12 VDC out

V+ Plus 12 VDC out

Flip up the yellow safety cover and attached the prepared wire ends under the L and N screw terminals.

Make sure the wires are tight and there are no stray wires when you are done.

Step 7: Prepare the First Set of Red & Black 12 VDC Wires

Measure from where the power supply will be mounted to the end of the first LED string.

Cut the red & black wires to the correct length and strip the insulation off the ends of the wires.

Step 8: Attach the 12 VDC Wires to the Power Supply

Attach the black wire to the V- screw terminal and the red wire to the V+ screw terminal.

Then snap down the yellow safety cover.

Step 9: Prepare the Strip Lights

The roll of strip lights I bought comes with a 5.5mm X 2.1mm power socket already installed, but because I am wiring in a power supply that does not have a power plug I just cut off the end with the socket.

You'll notice that after every few LEDs there are a set of 4 closely grouped copper pads. The LED light strip is designed to be cut apart at any of these locations.

Once you cut the end with the power socket off you will need to tin, or add some solder, to the two pads.

Step 10: Attach the 12 VDC to the LED Light Strip

Strip the other end of the wires you attached to the V1 and V+ of the power supply, tin the wire ends then solder them to the end of the LED light strip you tinned earlier.

IMPORTANT!!! - Notice that there is a + and - marked on the light strip.

The 12 VDC + (red wire) will always connect to the + terminal.

The 12 VDC - (black wire) will always connect to the - terminal.

Wire them backwards and the lights will not come on!!!!

Step 11: Test Your Work

Now you can finally test your work!

Plug the power cord in. If the LEDs don't come on right away then turn on the rotary power switch.

If the lights don't come on then most likely you have the red and black wires swapped at the power supply or at the light strip.

After testing, unplug the power cord!

Step 12: Measure Your Individual Light Strips

Starting with the first cabinet, the one where the power supply will be mounted, measure each cabinet length.

Just like earlier when you cut off the plug end, cut the LED light strips into smaller pieces that will fit under your cabinets.

Just like earlier, make sure all of the cuts are between the 4 copper pads.

Step 13: Measure Your Jumper Wires

You will need to connect the individual LED light strips together with jumper wires.

Measure the lengths you need then cut.

I ended up with 2 sets, or 4 wires, 2 red and 2 black. The jumper wires were all the same length for my cabinets but they may not be for your cabinets.

Step 14: Tin Your Jumper Connections

Strip and tin both ends of your jumper wires.

Then tin the copper pad ends of all of your LED light strips except for the very last one.

Step 15:

Solder your jumper wires to the ends of your LED strips.

Just like before, make sure the black wires go to the pad marked - and the red wires go to the pads marked +.

Step 16: Time to Test Again

Now it's time to test again.

Plug your power plug back in and make sure all of the strips light up.

If some do and some don't the most likely cause is you soldered the wires to the wrong terminals!

Step 17: Mount the LED Light Strips

These light strips come with double sided tape already attached to the back side.

Starting with the furthest light strip, carefully peel back the double sided tape backing and press the strip to the underside of your cabinets.

Step 18: Mount the Power Supply

Using 3M VHB tape or any other strong double sided tape, mount the power supply to the underside of your cabinet,

Note: The yellow safety cover should protect you or any adult from being shocked by the power supply, but if there is any risk of small children getting access you should mount the power supply in an electrical box then mount the electrical box under your cabinet!

Step 19: Enjoy Your New Lights!!!

Here is another before and after. You can see that the lights makes a huge difference!

One nice thing about these is they are only 12 VDC and you can handle them with no risk of being shocked as long as you use a fully isolated power supply. If your lights tend to pull down from your cabinets you can even use hot glue to re-attach!



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16 Discussions


2 years ago

Great job!

Could you not also use a TDL-2023 PIR switch instead of the on-off switch to make it motion sensor controlled?

1 reply

4 years ago on Introduction

When installing a rotary switch like that (or any switch in general on household wiring), you want to make sure you cut the hot wire and not the neutral wire. The hot wire is connected to the narrow prong on the plug. I could not tell which way you did it from the photos.

The hot wire carries all of the current. So, when the switch is off, you are cutting off the current at the switch.

If you instead cut off the neutral at the switch, there is still a hot wire running from the outlet to the device when the switch is off. Additionally, since the neutral is interrupted (and there is no ground wire in this setup), there is no pathway for the current in the event of a short.

There is an increased risk of electrical shock with the wiring configured this way. If the hot wire somehow gets in contact with the case and then you touch it, it is going to ground through you.

Additionally, you should note in your instructions that the hot wire (narrow prong) should go to the L (live) and the neutral wire (wide prong) should go to the N (neutral) on the power. I could not tell how you actually hooked it up from the instructions, or if it affects the operation of that power supply one way or the other.

5 replies
Tom Hargravefzumrk

Reply 4 years ago on Introduction

Actually, current flows back and forth between the hot wire and neutral wire 120 times a second. Installing the switch either way has the same effect, it disconnects the loop and stops current flow. And depending on how old your donor lamp is, you may find the two plug blades are the same width.

Technically you are correct for lamp wiring but not for the reason you mention. When wiring a new lamp you should make sure the narrow blade is wired through the switch so that when you turn the switch off to replace the bulb there are no voltages at the bulb socket. But there is no bulb or bulb socket here which is why I was not too concerned!

And fzumrk, even though I don't 100% agree with you thanks for the feedback!!!!!

fzumrkTom Hargrave

Reply 4 years ago on Introduction

While you are correct that the current alternates direction, all of the "work" is done by the hot wire. The push and pull of the electricity reverses direction on the hot wire. The neutral wire does not carry any current until the circuit is completed. If you examine your breaker box, the neutral bus is probably tied to the ground bus. If the neutral was actively carrying any current it would ground out. Also, the cycle rate is only 60hz, not 120.

As an example, you can power a device such as a light bulb by connecting it to the hot wire and the ground wire. Connecting it to the neutral and the ground will not power the device. You can also see this if you have a multi-meter. Set it to the AC voltage setting and touch the leads to the hot and to the ground, then compare this to to touching the leads to the neutral and ground. You will get voltage in the first scenario, but no the second.

Tom Hargravefzumrk

Reply 4 years ago on Introduction

You are wrong - look up an Edison Connection.

A Edison connection is the way all houses are wired in the USA. The transformer your house is connected to has a center tapped secondary. The voltage between either end and center is 120 VAC. When you turn on a light switch current passes back and forth between one of the outside legs center tap at 60 Hz, reversing direction 120 times a second.

The center tap of the transformer is just as "hot" as one of the outside legs but it's tied to ground through a ground stake, the same "ground" we are referenced to because we are standing on the ground. This is why no current passes though us when we touch ground we and 'ground' are at the same voltage.

Current passes back and forth between 'ground' and the hot leg, doing equal work both ways. You want absolute proof? Build a circuit like the one in my attached drawing and wire it across a AC plug. Each diode will block current one way and allow current the other way. If you are correct only one light will come on. If I am correct both lights will come on 1/2 bright.

Please let me know the outcome.

Also, ground and neutral are tied together in your power panel.

awsnapTom Hargrave

Reply 2 years ago

Tom, you are wrong. Voltage is merely 'potiential' or the difference between the lines. In AC, neutral - which you clearly understand is tied to ground and therefore constant - does nothing but provides the basis for the potential from hot. If neutral were tied to ground AND moving... think about it. Plus, why the hell would they call it NEUTRAL!!!??? You're example of the Edison (rich man's Tesla, but a different discussion) connection may be correct but you are trying to explain it while not understanding that HOT does not mean POSITIVE. Being AC, the hot flips between positive and negative creating the aforementioned potential in both directions. It seems that you are stuck trying to understand it as +/-.

Tom Hargraveawsnap

Reply 2 years ago

Explain to me why I'm wrong? I was just explaining current flow which does all the work.

And the center tap neutral is just as 'hot' as the other two legs, it's just referenced to earth ground so we have no current flow between neutral and ground. For example, if one of the 120V legs were tied to ground instead of the center tap and you touched neutral you would definitely feel a 120V shock. This is because now that 120V leg would be referencing ground. Also, the other 120V leg would now be 240V from "ground".


3 years ago on Step 19

This is so cool and really easy to follow. I so want to do this in my kitchen.


4 years ago on Introduction

Looks great and so simple to do.

One question, Did you install the LED facing the wall or the counter?


2 replies
Tom HargraveJuanS8

Reply 4 years ago on Introduction

I installed the LEDs facing the counter. I had not considered facing the wall & it would be an interesting effect.

I got the idea from a friend of mine who installed his above the cabinets. His lights bounce off the ceiling. His do a better job of lighting the whole kitchen while mine do a better job of lighting the counter top. It all depends on what you want out of the project!

lokipartsTom Hargrave

Reply 3 years ago on Introduction

I love your project. I am thinking about doing the same thing soon. I actually just did the same thing as your friend with my cabinets mounting an LED strip above them for a nice ambient light in my kitchen. Originally I actually just had a string of purple LED Christmas lights just sitting on top of the cabinets... Well actually even before that I had a very old set of white automotive underbody neon lights mounted above my cabinets but those were a little weird and I didn't keep them very long.

But I enjoy the ambient lighting effect so much that I recently decided to try a RGBWW LED strip and controller. I must say these LED strips are quite amazing. I honestly didn't know what to expect but the first thing that jumps out at me is that they are exponentially brighter than the LED Christmas lights that I used to have up there. Plus now I can fine tune the color and brightness depending or the desired effect. Now I am just trying to decide if I want to just do warm white under the cabinets or do a set like the RGBWW that I have above the cabinets even though I know that most likely 90% of the time they will just be used as warm white.


4 years ago on Introduction

Just a suggestion, have you thought of using a timer? LEDs are such low power you could have them kick on in the morning and evening with no worry of them burning out for years.

1 reply

4 years ago on Introduction

I've always loved the look of cabinets that were lit in this fashion. Definately somenthing I'm going to do when I have my own house.

1 reply