Inexpensive DIY Under-Cabinet Lighting

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Introduction: Inexpensive DIY Under-Cabinet Lighting

About: I run the following websites, among others: Take notes anywhere: http://www.typity.com Zelda fan site: http://www.hyrule.net

In this instructable you will learn how to set up and install inexpensive under cabinet lighting in your home with minimal cost and difficulty using affordable cold cathode tubes normally used for PC case mods. This is my first instructable. I will do my best to make it clear and easy to follow.

Why?

Previously when you prepared food in my mom's kitchen you would be standing between the ceiling light and your work surface, thus casting a shadow. Additionally, under cabinet lighting tends to look nice. It's quite the dramatic effect in person and definitely stepped up the look of the kitchen a lot. It's less harsh of a light in person and significantly improved visibility while working in the kitchen.

Cost & Power Usage

I was able to light my mom's entire kitchen for under $40.00 including all parts. Additionally, the lights are quite power efficient, using about 3 watts per light tube (I used 6 pair / 12 tubes total). Total wattage=36 watts, or 3amps at 12V. This is a little over half the power usage of a normal 60watt incandescent bulb. Your final project price will vary depending on your supplies and the size of your kitchen.

Compare With and Without

1. Under cabinet lighting on, Ceiling light off.
2. Under cabinet lighting off, Ceiling light on.
3. Both under cabinet lighting on and ceiling light on.

Step 1: Collect the Parts

Below are the parts and tools I recommend for this job. You can get away without some or substitute things. It's a pretty simple job to get this and set it up if you're handle with things and know the basics of electricity. This project is low voltage for the most part (wires between the inverter and lamp are very high voltage but you shouldn't need to mess with these at all) but of course always practice safety with electricity and unplug things before touching wires. BE SAFE!

Details for a few of the parts are listed further below.

Parts:

1. Cold Cathode Lights w/ Inverters* (2 light tubes per inverter)
2. Power Supply (12V DC for these lights)*
3. Wire for connecting power to inverters
4. Staples or something else to hold up wires under cabinet
5. Power Switch (optional)
6. Inline Fuse (optional)
7. White Paint* (optional; see below)

Tools:

1. Wire Cutters
2. Soldering Iron
3. Solder
4. Electrical Tape
5. Multimeter

*Cold Cathode Tube Kits

I used white 12" tube kits from petrastechshop.com. They put out quite a bit of light and come on quickly. The light is less harsh in person than the camera makes it appear. They were on sale at the time for $3.75 or something. Shop around for the best price. Make sure the kits you get come with TWO 12" tubes and an inverter. Some places try to trick you with just one tube included for the same price. One of my tubes didn't light and I emailed the store and they sent me a working replacement which I received two days later.

*Power Supply

I used a HIPRO brand DC Switching Power Supply designed for a laptop. I got it from sciplus.com for about ten bucks. It's rated for 3.33A at 12V, aka 40W (watts = amps * volts). It gets quite warm as I'm approaching it's upper rating. Each individual lamp uses about 3 watts (6W for a pair) so total up your expected usage and get a supply over that. I am using 12 lamps (6 inverters) for a total of about 36 watts.

*White Paint

Before you start wiring things up, decide if you want to paint. If so, paint first so it can be drying while you work! Depending on how bright you want the lights to be and the color underneath your cabinets, you may want to paint under your cabinets to help reflect more light. I opted to paint the bare wood under the cabinets white to help with reflectivity so more light would reflect downward. This is entirely optional but it should help. Other colors may help soften the light, such as a pastel tan or yellow.

Step 2: Prepare for Wiring

The first step it to get power to your inverters. Use caution as you will be working with electricity although you should just be dealing with low voltage. Safety first!

See Step 1 for information selecting parts.

1. Power Supply

Point A in Figure:
With the 12V DC power supply unplugged, prepare it by cutting off the small DC connector on the output. If you're extra handy with things and have a jack/plug that fits the 12V connector, you could solder in a connector like I did so you could replace the power supply easily. I found the connector on an old set of computer speakers. Separate the two wires of the output and use a multi meter to check which wire is positive and which is ground. Mark this wire for later and unplug the power supply.

NOTE: If installing this in a camper or place where 12V DC is already available, you can skip the power supply. DEFINITELY use an inline fuse in this situation though to protect your power source and wiring.

2. Fuse (optional but recommended)

If you are installing an inline fuse, connect it inline on the positive DC wire, near the power supply. It is best to put this close to the power supply before the switch for the most safety. This is useful if you get a short so wires don't melt or catch on fire. Most power supplies include a fuse in them but an extra one won't hurt and it may also save your power supply from damage. Choose a fuse slightly higher than the maximum current you expect your setup to use.

3. Switch (optional but recommended)

A switch is useful if you want to be able to easily turn the under-cabinet lighting on and off. I used a lamp switch a friend had. Make sure it is rated appropriately. If your power outlet is on a switch you can just use that instead. You can also just plug and unplug the power supply but you probably don't want to do that all the time as things may wear out and it would be inconvenient.

4. Inverter

Point B in Figure:
Cut off any cabling, switches, and plugs going to your inverter's INPUT, noting which cable is black or connected to the black wire. This is your ground. Do NOT cut off the cables going from the inverter to the lamps.

Step 3: Connecting It All Together


1. You will want your inverters to be wired in parallel. I soldered all of my connections for added durability and to lessen resistance. Your connections don't have to be beautiful. This is a simple job of connecting wires.

2. Unless your lights are going to be very close together, you will want to use additional lengths of wire to connect to your power supply to each inverter. I ran a single line of 2-conductor appliance wire around the kitchen and cut into it periodically to splice into.

3. Connect the wire coming from your power supply's ground to the ground on all of the inverters. Connect the positive wire to the switched positive wire. See the diagram below for more information.

4. Be sure to properly insulate all ground and positive wires from touching and secure all connections so they are tight. You can use the multimeter to check your wiring at this point and then give it a test.

5. If things do not immediately light, turn it off quickly and unplug everything. Begin to troubleshoot. Visually inspect connections, use your multimeter to find problems, and input extra stuff to narrow down the problem.

6. If all is well, move on to mounting the lights in the next step.

Step 4: Mounting the Lights


Be sure to note how the lights will be visible at different angles. Keep in mind things like different elevations of rooms nearby. For instance, my mom's kitchen is higher than the next room so while in the next room you are low and you can see the tubes. Also keep in mind where you will be placing the inverters and routing wires.

Velcro

The kits usually come with velcro backed with adhesive. Depending on the surface underneath your cabinets this may work fine or fail miserably. Underneath my mom's cabinets the wood is very rough so the adhesive can't get a very good hold. On smooth surfaces the Velcro adhesive sticks exceedingly well. Peel off the protective paper on one side of the Velcro and stick it to the ends of the light. Remove the protective paper from the other side of the Velcro and stick it under the cabinet, spacing as desired.

Other Mounting Ideas

Epoxy: Simply epoxy it up using epoxy rated for adhering to plastic and wood.
Cable Ties & Staples: Staple a cable tie loop around each end of the light and inverters.
Metal "U" brackets: Nail or screw in metal "U" brackets from the hardware store to hold everything.
Drill holes and cable tie: Drill small holes on each side of the light and loop a cable tie through.

My mom's friend ended up enhancing our mounting later since the velcro began to fail since it was applied to very rough wood and couldn't grip it well.

Step 5: Finishing Touches

At this point it should look pretty nice. However, you have pesky wires hanging down in places and lights may be visible. Here are a few more thoughts on how to improve the setup.

Wire Management

Use staples or other cheap wire management hardware to hold up your wire. You can find all sorts of hooks things for holding up wires at your hardware store or even the ever-present Wal-Mart. I used raised staples with a staple gun and it was fast and easy. Just take care not to puncture any cables. Don't use a staple gun that doesn't leave the staples sticking far out of the surface or you should cut into the wire.

Hiding the Lights

If your lights are visible, there are a few ways to hide them and make them more pleasing. You can add some trim to the edge of your cabinets to obscure the view, or you can go to your hardware store and find plastic hoods to fit over them. Though my mom's are slightly visible from the other room since the kitchen is raised, we opted to leave it as is since it looks great when you're in the kitchen.

Keep the Power Supply Cool

Be sure to get a power supply that is rated high enough for your setup. Mine is being pushed pretty hard so it gets quite warm. It is within limits but to help make it last longer I cable tied on a couple of CPU heatsinks with CPU grease to help dissipate heat. It seems to pull the heat off pretty well. Be sure to keep your supply in ventilated area and not to put stuff on it. If I did this over, I would get a slightly higher rated supply so it wouldn't be pushing it to so close to its max current output.

Conclusion

I hope you found this instructable informative and useful. I was able to significantly improve the lighting in my mom's kitchen on a tiny budget. While pricing 'professional' under cabinet lighting systems, the prices for this kitchen ranged from $400 to $2,000. I think my $40 version was well worth it, especially compared to the professional version's much higher costs.

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79 Discussions

Kitchen really amazing. Interesting if it can integrate well into various kitchens, saw a similar cuisine in http://kitchenpt.com/ interesting Outeda, really impressive about the honor.

This how-to guide is very helpful especially for people who are not that inclined in this sort of work. Aside from the light option you've presented, I am also considering a set from this review list http://www.reviewswise.com/indoor-kitchen/indoor-appliances/under-cabinet-led-lighting/ . I am hoping I could pull this off.

I wish you would do a separate 'ible' on power supplies. Like most, I have a box full of old inverters that powered obsolete or dysfunctional computer equipment. Would one of those do to power the lights? What should I look for to be certain that I won't set the house afire?

Thanks for a great instructible. I'm definitely gonna do this one.

12 replies

Consider LED lighting strips instead, less power required and there are a number of off the shelf solutions available. LED strip comes as one role and can be cut where needed for much neater installation. Cold cathode was awesome 7 years ago, but we've now harnessed the power of, well, saving power!

Good suggestion!

I would still like to have more information about re-purposing those power inverters. Do you know if they can be used to power LED strips?

I realize that your question has already been answered, but I thought I would mention that I have done this with a number of my old power inverters sitting around. For the most part all of the leds I have had are 12v so the only thing I have had to watch for is the amps. It seems pretty realistic to run about 20-30ft of the led light strips on a 3amp or less 12v inverter. The strips I use are very similar to these https://www.amazon.com/Flexible-Daylight-Non-wate...

The only notable difference with the "waterproof" ones is that they have a pliable tube that wraps around them the full length, I personally prefer the non-waterproof ones because they have the double-sided sticky tape on the back.

As a side-note I would highly recommend plugging the inverter into an outlet that is ran by a motion sensing switch, I did this on my kitchen and it is fantastic. When you enter the room you will hear the motion sensing switch click, and about 1 second later the lights are on, stay on for about 3 minutes (with motion) and then turn of automatically. I did the motion sensor as a 110v normal switch with a standard 110v outlet that powers up the inverter, That way the inverter wasn't powered up all the time just to operate a 12v motion sensor.

Howdy Kris!

Thanks for the link to the LEDs. Can you suggest a brand of motion activated socket? Looking online I'm a bit confused. What I would prefer to do is to plug the motion detector outlet into an existed outlet on house wiring and then plug an inverter/supply into the motion detecting unit; thus LED lights I power with inverter/supply will come on only when there is motion in the kitchen.

Again, thank you for really good information.!!!

I don't think I fully understood how you want to do that.

You want to connect the motion sensor to an existing 110v outlet? / Or is it an existing light socket?

There are a couple of options depending on what you want to do. If you want to plug into a standard wall outlet you could extend it with a small cord into a project box where your motion sensor switch is, and outputs to an outlet mounted in the same box, then plug the inverter into that box. This would provide you a moveable solution, but binds everything to that box.

If you are using a light socket that is no longer used for something else you could replace your light switch with a motion sensor like this one

http://www.homedepot.com/p/Leviton-180-Degree-Pir-...

and then replace the socket itself with an outlet, or one of those old adapters that spins into the light-socket and gives you prongs for a plugin, then you would plug your inverter in there. That switch could also work in the project box as well.

If you don't have a replaceable switch that controls the light socket you could also run the invertor directly off of the socket, and then put a 12v motion sensor after the inverter.

https://www.amazon.com/Sensky-BS010W-Motion-Distan...

The downside to this design is that the inverter would be on all the time which would probably decrease its lifespan and generate heat.

I had something like this in mind. The electrical outlet in the wall would have a motion detector with female outlet plugged into it and the inverter would be plugged into the motion detector and would power the LEDs.

Source Detector Inbverter.JPG

So something like this

https://www.amazon.com/Westek-MLC4BC-Indoor-Activa...

or maybe this if you want the motion sensor separate

https://www.amazon.com/Westek-MLC12BC-4-Indoor-Act...

plug your inverter into that and your good to go.

I personally would desire the one with the separate motion sensor that way you can use a more concealed outlet and just put the motion sensor in a more visible location. You could also focus the sensory area by pointing the sensor through a tube if desired.


Thanks, again, Kris!!!

I appreciate the links. I also like the idea of lighting the kickspace beneath cabinets. Great idea!

I haven't heard anyone mention this yet but I am planning on sub lighting the base of the cabinets as well, so the floor is well illuminated.

Also thinking about doing this in the bedroom to light around the bed so it is easier to see when coming into bed during the night.

If the voltages match (i.e. don't be using a 15V power supply with a 12V light), and the brick provides enough max amperage (i.e. your lights require say 5amps total and the brick is capable of say 8 [the amperage rating is the max available to be asked for, it will only deliver UP to that max]) then yes, you can use them. Cut off the laptop portion of the cord, verify which cable is positive and which is negative, and go to town soldering/splicing.

If you have a check online (eBay/Amazon/your local online marketplace) you'll find plenty of listing, which will stipulate power requirements. Some are 5v DC, some 12, if the LEDs are non-programable/not individually addressable then the power consumption will be much less. Check the polarity of your adaptors and if needs be, you can remove the jack. I'd be surprised if you couldn't utilize them ?

This is great, but you can get LED under cabinet lighting for under $20.00 for a 4-strip at IKEA...

The set I installed at my last place are still going fine and they were installed 7 years ago. Hope that helps.

My thoughts after doing this on two kitchens:

- I used flexible LED strips on one and LED bar lights for the other. It doesn't really matter that much what they look like because they are generally out of sight. The flexible ones can be stapled, glued or tacked in place. The bars can be supported by a wire or string loop.

- I get LED units rated for 12VDC. They have their own regulators built in. I find 12 volt bricks in thrift stores for $2 to $3. Make sure the current rating is higher than the combined current of the lights. (I also plan to run battery power in the house from a solar charged battery for use in emergency or just to save power cost)

- I have used ropelight for low glare lighting(very nice in a bathroom, mounted at the wall/ceiling. Some of these have an annoying flicker that drives some people crazy. They will need an adapter circuit if this bothers you.

- I put my lights on a motion sensor. This way you always have light when you enter the room and it always turns off when you leave.

Very nice and well done. ;-)