Cheap Diy Light Build/retrofit

[Mikaila31]

This thread is focused on building a DIY light from scratch or retrofitting an existing fixture. A few methods I use may be uncommon and still somewhat unproven. The point of this build was to get the most light for the cheapest cost, but with maintaining good efficiency. Though with any DIY I am not responsible for any damage caused by constructing a DIY light.

To start with I have been using CFL ballasts to power linear tubes. By CFL I mean the spiral energy saver bulbs. This takes the cost of the ballast from being one of the most expensive part of a fixture to about $1-3. However it only works well with wattage below 23-26 watts since these are the more common larger sizes of CFL bulbs. You can certainly go higher, but the cost jumps quiet a bit. (for example 40 watt spiral CFLs tend to go for $8-10). This method also works best with T5 bulbs, these are closest to the diameter of the spiral compacts and also one of the more efficient linear tubes. However it is not limited to T5 bulbs, it works with T8's or power compacts. This method allows for a lot of customization including underdriving or overdriving bulbs, but I will go into more detail later.

I will only briefly cover mounting a fixture. Mainly because this is very variable depending on how you are mount the bulbs and to what.

First we will start with a brief overview of fluorescent lights. T8, T5, PC bulbs are all very similar in construction. The bulbs are powered by ballasts, which increase the voltage required to start the bulb. Wires then run to each pin of the bulb. They are pretty simple overall. The wiring can vary a bit depending on the individual ballast used. This is a general diagram of a linear bulb fixture.

Also common with T8 fixtures are the "starter" type. These function similar as above, except instead of a ballast they have a transformer. The Starter is a capacitor that functions to increase the voltage required to start the bulb.

Now for building your own fixture!
Step 1: locate a ballast
As I mentioned above I have been recently experimenting with using Spiral CFL ballasts to power other bulbs. This greatly decreases the cost of the fixture. You need to buy a spiral CFL with the proper wattage you want. For T5's and PC bulbs the wattages are basically equivalent. Example a 14 watt CFL ballast will power a 14 watt T5 at around its normal output. For T8s however I have found you need a higher wattage ballast then the wattage stated on the bulb, example a 23 watt CFL ballast to power a 15 watt bulb. This is because of the larger diameter of the bulb. I personally would stick with T5s or PC bulbs, but if you have a T8 fixture with a dead ballast this is certainly a cheap way to get it up and running again. These are electronic ballasts and run very quiet and provide instant start up on all bulbs I have tried.

To get a spiral CFL ballasts you need to take apart a spiral CFL. This is very simple and poses no danger as long as you don't break the bulb. Take a screwdriver and run it along the seam on the base of the bulb. I found its easy to run it all the way around the bulb just separating the two parts. Then start prying them apart. Eventually the base should pop open and reveal the ballast.

Above is a westinghouse 23 watt ballast. All the brands I have taken apart are very similar. Westinghouse and Sylvania I prefer over GE, but all brands will work. To those familar with lights the wiring shown on the CFL in the pic will look very similar to a normal ballast. The ballast has two wires for power and these need to be cut. Two brands, Westinghouse and Sylvania, have a resistor that is kinda hidden in a white tube (can see it in the pic). Try not to cut it off, but if you do its easy to just reattach. Then their are 4 small pins on the ballast that have wires wrapped around them and run to the bulb. These need to be unwrapped and the ballast is free.

These are examples of removed ballasts.

Step 2: wiring! (Its not as hard as it seems. Honestly!)

Now the little pins on the ballast are always together in pairs, either on opposite sides or offset from each other. Wiring these ballasts to a different bulb is as simple as attaching wires to the pins and running them to the pins on the bulb. One pair of the pins runs to one end of the bulb and the other pair goes to the other end of the bulb. The exact pins you connect to on each end of the bulb DOES NOT matter. This makes the wiring very simple as multiple ways are correct. The two power wires can be connected directly to a standard AC power cord. If you don't have one buy a $1 extension cord and cut the socket end off it.

This is a simple wiring diagram. I color coded it to show which wires are interchangeable. Basically if you cross the two red wires with eachother is doesn't matter, same with the two blue wires, or the two black ones. It will work regardless. However if you cross two different colors, a blue and a red, it will not light. But you will NOT damage the ballast either if you by chance mess this up. These ballasts like all ballasts use high voltage. Safest way to work with them is do NOT touch it if it is plugged in, this goes for all electrical work.

Connecting wires to the pins is the trickiest part, but still not very hard. I could careless what wire you use, but every light fixture I have taken apart uses primary wire, 18 AWG(american wire gunge) rated up to 300V. I prefer to use this type of wire, but have occasionally used lesser rated wires. You can get it at most home improvement stores usually $5 for more then enough. This wire is often solid core. I CAREFULLY bend the pins on the ballast till they form an almost closed hook. Make a similar closed ring with the wire, then stick the two together and bend it so they are both fully closed. The tighter the better, a lose connection is more likely to make the fixture flicker when it is moved.

Now there are two ways to connect the wires to the pins. Either with endcaps/socket or making a DIY connection with terminal rings. Proper sockets are much more preferred, but with T5 it is doubtful you will find these locally. I would suggest getting them online along with the bulbs or using the terminal rings. The terminal rings are not as convenient as the twist sockets, but get the job done regardless. Its harder to get the bulb in and out, but its not like this is done very frequently. The ring terminals are super cheap($1 for 2 dozen), but you do need to buy extra parts for mounting the bulb.

If you use ring terminals they should be 16-14 AWG size, as this size fits snugly over the bulb pins. You need to trim the insulation on them down so they are shorter. If you are using T5 bulbs half of them need the insulation fully removed or they won't fit. For T8s or PC bulbs leave the insulation on.

Then connect the wires from the ballast to the ring part of the terminal. Then each terminal fits on a pin. The rear bulb shows you how they are wired. Once you are done the connection should be covered like the front bulb has, to avoid to a connection between the two wires.

Once you attach a powercord to the ballast your basically done with wiring. Below are a few examples.

This is a 4 ft Normal output T5 with a 26 watt ballast.

A 14 watt NO T5, but running off a 23 watt ballast making it basically a HO T5. I plan to swap out the bulbs when ever I get around to ordering HO bulbs.

Retrofit into a standard T8 light strip, using the existing hardware. I've been using this fixture for a month and a half without any issues. The only difference you can notice is instant start up, no high pitch buzzing, and the fixture is at least 50% lighter in weight.

Okay tired of typing for now, but more to come!

 

[KrazyKuhli]

Wow this is really handy, I planning on making a new hood out of wood and was thinking where to put the starter box (its huge and has short wires) Least with this plan I can make it slightly neater.

Cheers for sharing this..


P.s how do you protect the ballast from the moisture?

 

[Mikaila31]

Wow this is really handy, I planning on making a new hood out of wood and was thinking where to put the starter box (its huge and has short wires) Least with this plan I can make it slightly neater.

Cheers for sharing this..


P.s how do you protect the ballast from the moisture?

Yah the CFL ballast provide a few advantages over the big normal ballasts. They are much smaller and cheaper which helps retrofitting more light into existing fixtures where space is limiting. They also stay very cool, unlike normal ballasts which often get too hot to touch. The CFL ballasts should last just as long as they do in the original spiral CFL bulb, or longer since they are mounted away from the bulb.

Some of their limitations is they are for lower wattage and you need a ballast for each bulb. There is no way to power two bulbs off a single ballast. This allows for a lot of customization though. You can install on/off switches if you chose. I always run my lights off timers so never really bother with this. You could control each ballast with its own switch. However if you have a dual fixture their is NO harm in providing power to a ballast that does not have a bulb attached. Basically a dual fixture can light 1 or 2 bulbs.

You SHOULD NOT power one bulb with two ballasts. Now some people may even laugh at this idea, its a silly thing to even try. Regardless I did and surprisingly it did actually work without instant frying of the ballasts. I wired two 23 watt ballasts to a 55 watt power compact and they could light it to is normal output. This is still NOT a viable method, as those ballasts are lucky if they last very long at all without frying each other. I could go into detail but the simplest way to explain it is that ballasts put out an AC current with a certain frequency. When powered on two combined ballasts sometimes match frequencies and can work together, other times the frequencies will be offset and the two ballasts will be directly working against each other. In the latter case it leaves you with a strobe effect and ballasts that sound like angry bees. You have a 50/50 chance for matching frequencies every time you power on the ballasts. In short, it works, but WON'T work for very long. Sooner or later the two ballasts will destroy each other.

The ballasts should be protected, this is really important if the fixture is exposed to water. If you have a lid or barrier to reduce moisture getting into the fixture, its not as important. Best way I have found to do this is to cut up a yogurt container once you have the fixture mounted. Fit the yogurt container over the ballast then make notches for the wires to pass out. The tighter the fit the better. Then use silicon, hot glue, or expoy to seal the yogurt container over the ballast. Also electrical tape should be put on the bottom of the CFL ballast to protect it. If the fixture is more exposed to condensation I would suggest liquid electrical tape used on the ballast and the terminal rings. This can be painted on and provides a good waterproof seal in addition to the yogurt container. I would cover the entire bottom of the ballast and the pins where the wires connect. Don't however cover the entire ballast as that may cause heat issues.

Below is a ballast with electrical tap attached to the bottom. The capacitor(s) I bend down to make it more compact.

Then the yogurt container goes over it. I still need to seal this one to the fixture but it gives you the basic idea. This is also an example of a dual fixture.

I would mount the bulbs and reflectors before mounting the ballasts in the fixture. Its easy to move the ballasts around, but not so with the reflectors or bulbs.

More still to come!

 

[Mikaila31]

Step 2: Make reflectors

Reflectors greatly increase light output by directing light into the tank. However reflectors need to be made properly or their effect can be quite negligible. The reflector should be large and the proper shape to reflect light without causing a ton of restrike back at the bulb. The bulb should also be mounted about an inch from the base of the reflector to provide space for getting the light around the bulb. Mounting a bulb too close to a reflector decreases efficiency. I tend to copy the general shape of ahsupply.com reflectors, as these are really good reflectors. They are much to expensive for a cheap DIY project though. To make reflectors you need 6" wide aluminum flashing, which you can get for about $5 for 10 feet. You need to cut it to the desired length then trim it so it is only 4" wide. Be very careful with this material as it is sharp and has sliced me really good before. You need to take a pliers or a hard edge and slowly work on bending it into shape. Using a hard edge like a wood block gives you a nicer product then a pliers. Pliers gives the ripple effect you see in the pics.

The proper shape is shown below with measurements. Once bent the reflector should be about 2.5" wide.

Final step of the reflectors is to punch two holes through it. These should be measured to match where your clamps go if you are using clamps. If you use proper T5 endcaps the reflector is mounted separately, the refeclector also need to be shorter then the bulb if you are using proper endcaps =/.

Step 3: Mounting the bulbs and reflectors.

In this part the bolts you use to connect the bulbs will differ depending on your fixture, but the general idea is the same.

1st you can use proper T5 endcaps or a heavy duty pipe hanger. I would only use proper endcaps if you order the T5 bulbs from that same website, as the endcaps are not worth shipping on their own.

I decided to use galvanized split ring hangers as a makeshift way to mount the bulbs. I could get these locally for $1.30 each. The size you need is 1/2" and even this is slightly too big for T5's, but we can make it work. Check home depot or ace for these, in the pipe hanger section.

Now you need bolts and some nuts. Here you hardware may differ. Its important that the bolt has a large head or you will need to use some washers. The bolt does not need to actually fit either the pipe hanger or the first nut, just as long as they slide on it works. The first nut is a spacer that puts more distance between the bulb and the reflector. Then the reflector goes on, followed by a 2nd nut that actually fits the bolt and holds everything in place.

Be careful using these, if the pics don't show it they are really heavy duty. Properly used the bulb will be held very firmly, if you over tighten them they will crush the bulb. Use the minimum tightness that holds the bulb. The pic below shows how the hangers are slightly oversized and you need the bolt head to stick up far enough to clamp the bulb. Properly clamped the bulb will not wiggle, turn, or slide in the hangers.

Last step is to drill holes to mount the reflectors and bulb to the fixture housing. The bottom bulb is done correctly. The top ones reflector is a little short, but if you use endcaps you would have to do a similar separate mounting of the bulb and reflector.

Then let their be light Total cost was about $30 including the bulbs, but not including the wooden housing. Dual T5 HO at around 46 watts total.

 

[KrazyKuhli]

So I need to get a 14W bulb to get a 14w Ballast to run a 14W tube light?

 

[Mikaila31]

So I need to get a 14W bulb to get a 14w Ballast to run a 14W tube light?

Yes for T5's. And thats running around normal output. The thing with florescents is they are very easy to modify. A 21" normal output T5 is 14 watts, a High output of the same size is 24 watts. The only difference in the bulbs that I know of is HO T5's are rated to run at the higher heat/shorter life ect. There is nothing stoping you from overdriving or underdriving bulbs. Overdriving is using a higher watt ballast then the bulb is rated for, the bulb will run hotter and have a shorter life. T5 HO are just T5 bulbs that are designed to be overdriven. As long as you overdrive within reason your okay. Overdriving gets more light out of a bulb, but efficiency is lower. Basically T5 HO is about double the watt of an NO T5. It produces more light, but not double the light.

Over-driving can be done with any bulb, not just T5. You can also overdrive at different levels. If you want more light then a NO T5 can provide, but not HO T5 levels. Then you can pick a range in-between NO and HO if you want. It comes down to the ballast, if I had done this fixture with 18 watt ballasts it would likely end up in some range between NO and HO fixture. The bulbs in this fixture I bought as 14 watt T5s, however they are being driven by 23 watt ballasts, so producing much more then its normal output.

You can reverse the idea. If you took a 24 watt bulb and wired it too a 14 watt ballast it will still light without an issue. However its only running at 14 watts because that is what the ballast is supplying.