Anybody rewire a fluorescent desk lamp with LED?

[borges1]

Cool looking project. Ive always liked those old lights - so much nicer than anything you can get now.

I have built a number of all sorts of lights over the years using may different LEDs. what you want to do is pretty simple. If it were me, i would use a small 12v transformer to replace the ballast, then just use 12v LED COB tape to replace the light. I would also replace the vintage internal wire, and to make it easy on you id get the COB specific connectors, which can be bought is small assortment kits - no soldering required. All these parts are easily available on amazon. For that size light the smallest stand alone transformers are enough (i cant imagine you exceeding 5w) COB LEDs i prefer because the light is more 'even' and they can be cut more frequently to get the length right. With some patience i bet you could get the led strips inside an old T5 bulb if you really want the vintage look

a few tips: LEDs come in different colors. white is the only reasonable option here, and i use 4500k lights all the time. They are very 'white' but not blue good to work under. You may want color closer to 2500k-3000k for a more traditional yellowish light.

buy the highest density COB tape you can. More lumens per foot is your friend for a task light. Not bright enough is a bummer. it cost a bit more, but is very worth it.

.... which leads to adding a dimmer. If you can i'd add a dimmer. That means making sure your transformer/driver is dimmable (a bit more $) i like to use the capacitive dimmers for leds, which i dissassemble and rebuild into custom switches using small brass rod touch points soldered to the orginal capacitive sensor. ive been able to add about 10" of 22ga wire and still have them work. its a cool trick. or you can just use a switch that replaces the one you have, but is a dimmer.

a lot of the lights i have made were actually constructed from cheap LED desk lamps, completely dissassembled, then rebuilt into interesting wood/stone custom fixtures. i found that was helpful in learning how the whole things works. you get a 120v plug, then a transformer, dimmer, and often a usb plug for charging - which are designed to work together. all features which are nice to have in, suprise suprise, a desk lamp. might be worth a $20 lamp. if you go that route, and want to use the parts in your lights, make sure the LED output is 12v. COB tape needs that voltage and some lamps are 5v output.

 

[markba633csi]

FYI: COB stands for "chip on board" meaning LED chip(s) soldered to a circuit board with connection terminals provided

PS: I converted an old Tensor desk lite by fitting a LED chip bulb (aliexpress) with a 56 bayonet base. Fit right in and worked- no mods needed

 

[SLK001]

You might have to replace the switch. My old desk light used a momentary, push-to-start button to light the tube. When you wanted to turn it off, you simply pressed another momentary switch, which broke the circuit, thus extinguishing the light.

 

[whitmore]

If memory serves, those desk fluorescent lamps used a T8 lamp; the lamp sockets have
a different spacing than a T5 will fit.

There's two types of replace-fluorescent-with-LED creatures, one of which uses low
voltage strings of LEDs and keeps the ballast (heavy transformer-like thing) in circuit.
That variant is relatively reliable (low-voltage strings have fewer parts to fail than
high-voltage strings). The ones that require you to bypass the ballast work at line voltage.
Both of those flicker (which isn't a good effect on moving machinery).

Best for a machine work lamp is something with a DC filtered power supply (maybe just
a wall tumor) that delivers constant (no-flicker) safe low voltage, but I'm unsure of the T5 or T8 offerings
being compatible.

As others mentioned, the push-to-start and push-to-stop buttons must be designed out.

 

[Aaron_W]

As usual I may be over thinking this. I ran across this video on you tube, a very similar if not identical lamp to one of the ones I'm looking to fix.

He essentially just gutted the lamp, cut the cord on an LED light bar, ran the cord up through the arm and reattached the cord. He uses the included remote to turn the light on and off.

You might have to replace the switch. My old desk light used a momentary, push-to-start button to light the tube. When you wanted to turn it off, you simply pressed another momentary switch, which broke the circuit, thus extinguishing the light.

I'm glad you mentioned this I'm almost positive that is the type of switch on these lamps, and I would have tried to wire the switch in. I'm assuming from your comment that is a switch that only works with fluorescent bulbs?

 

[markba633csi]

If I recall the momentary buttons on those lamps are in lieu of a glow starter. Pushing the on button heats the lamp filaments then
releasing gives an inductive kick from the ballast to start the lamp. That's why it sometimes took a couple of tries to get them to light.
The ballast then smooths the AC current to minimize the lamp flicker when lighted.

 

[tailstock4]

I like the old lights, too. I’ve converted several of them to LED. I pull out the original fluorescent, usually leave or make a reflector and add a short strip of LED lights. I replace wiring and switches. All the lights in the pictures included have been converted to LED except for the brown lamp on the desk. It is the original fluorescent.

I also included a few pictures of machine lamps that I’ve rewired and painted and used an LED flood lamp – like you might use a on back porch.

These were all pretty easy to do except the one on the Monarch 10EE. Its shade was completely crushed, and the lamp arms were bent. However, I was eventually able to restore it to good working condition.

 

[DavieJ75]

I replaced mine with t10 leds, dirt cheap on amazon and then switched the cord over to dc and use a wall wart. 10 leds is as bright as the ringfloro ever was. Just had to make a few holes to mount the leds.

 

[Aaron_W]

I like the old lights, too. I’ve converted several of them to LED. I pull out the original fluorescent, usually leave or make a reflector and add a short strip of LED lights. I replace wiring and switches. All the lights in the pictures included have been converted to LED except for the brown lamp on the desk. It is the original fluorescent.

I also included a few pictures of machine lamps that I’ve rewired and painted and used an LED flood lamp – like you might use a on back porch.

These were all pretty easy to do except the one on the Monarch 10EE. Its shade was completely crushed, and the lamp arms were bent. However, I was eventually able to restore it to good working condition.
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The brown one on the bottom is similar to the other light I have, only it has a flexible gooseneck instead of the articulated arm.

When you say LED strip lights, you mean like the lights sold for under cabinet lighting?

I have a Davis and Wells bandsaw with a small light, I was going to get a small LED flood light to fit it, but it uses a standard screw in bulb so the only trick there will be finding a small enough bulb to fit it, and I've seen several candidates, I just need to remember to get measurements before heading to the store. I always remember when I'm standing in the light bulb aisle.

 

[tailstock4]

The first three pictures are of the small LED bulb I used in a miter bandsaw with the last picture of it installed. The other pictures are of the largest LED bulbs I use. I’ve included a picture of it with it in use on an Acra mill. I also use a middle size bulb.

These seem to last a really long time and the produce little to no heat – which is a big plus. I bought these bulbs and the small under counter strip lights at Lowes/Home Depot.