hey I have this old desk type lamp over the lathe, I just painted it too match it was ugly brown. someplace well taking it apart for paint I've buggered something up, either the coil (theres 2) or the capacitors ( think that's what they are? anyhow it has 2 17" flourescant bulbs I was wondering what would be required to convert it over to led... does led use the 120ac line voltage or does it need converted? I would probably have to replace the switch system as well.. anyone have any wisdom on these old lamps the coils are hidden in that bubble down by the base...under the asbestos ;p
desk lamp to led?
- Thread starter RAMBIN
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Platonic Solid
Well-known member
Gut the starter and transformer in the base. Buy 2ft LED retrofit bulbs. Rewire according to 2ft LED retrofit lamp instructions = running 120VAC directly to lamp holders. Here's a lamp that is single end powered (link) - thus requires non-shunted lamp holders (which yours very likely are).
I've done a few of these conversions to LED. The ones I did had lamps that were 15" to 18" long, and there's no good LED tubes for this. So, I used LED tape instead. There will be a little driver that you might be able to bury in the space where the ballast is now. Run the wire thru the neck. You might even be able to keep your switch. Added bonus: with color changing tape, you can make it red, green, blue, yellow....
Good luck,
CD
Good luck,
CD
Platonic Solid
Well-known member
I messed up. I see OP said 17" which made me think F17T8. Not likely to find retrofit bulbs for 17" bulbs.
rlitman
Well-known member
That’s a Dazor lamp. Those are big money nowadays. If you don’t like it, sell it, and get the LED you like.
4xdog
Well-known member
I have that same fixture -- painted mine semi-gloss black over 35 years ago.
IIRC, one needs to hold the on switch down to start the fluorescent tubes, then release to leave on.
There are, I believe, LED conversions. Perhaps like this one:
https://www.amazon.com/dp/B004LFAACI/?tag=atomicindus08-20
IIRC, one needs to hold the on switch down to start the fluorescent tubes, then release to leave on.
There are, I believe, LED conversions. Perhaps like this one:
https://www.amazon.com/dp/B004LFAACI/?tag=atomicindus08-20
what about using 2 12" led replacement t-5's staggered
I took it apart for paint..it was gooped in dark brown paint at some point.. after putting back together it no longer fires cant be anything serious I notice one of the wires going into the coils had unwound abit.. need to look at it more.. are parts available? I did find a date inside of 56? I was just thinking led would be briter and an easy fix if it was available instead of trying figure out what was wrong with the coil and or capacitors?
Ahh, can't blame you then. You might check to see that the push button switches are working. They are momentary, the black is normally closed and the red is normally open. If the aren't used in a while or something gets in the contacts then they won't work.
If you do go LED those type of switches will not work though, you'd have to replace with something else.
If you do go LED those type of switches will not work though, you'd have to replace with something else.
Platonic Solid
Well-known member
Take pictures of what you need. Never know what I have in stock from 1955.
I'd venture a guess that the light takes an F15T12 or F15T8. These are extremely common sizes and usually interchangeable, they are 18" lamps but that is measured to the end of the pins. If you are just measuring between the sockets then that is your problem.
rlitman
Well-known member
Mine says F15T8 right on the bulb.
Edit: and I see LED bulbs that will fit this lamp if you bypass the ballast.
Edit: and I see LED bulbs that will fit this lamp if you bypass the ballast.
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CJ7VFR
Well-known member
I have the same desk lamp except mine is the one with 20 pound base instead of the clamp for the side of a desk. I have had it for over 30 years. I love it!
I still use the fluorescent bulbs in mine because you can find them in big box stores like Home Depot or Lowes. They even have them at some pet stores because a lot of 20 gallon fish tanks use them in the hoods.
As rlitman said, I have also seen LED replacements in this size (F15T8) sold at places like Amazon, so they are out there if you want to buy them. The prices for the LED's seem to run about 50 percent higher than the old fluorescent tubes.
Jim
I still use the fluorescent bulbs in mine because you can find them in big box stores like Home Depot or Lowes. They even have them at some pet stores because a lot of 20 gallon fish tanks use them in the hoods.
As rlitman said, I have also seen LED replacements in this size (F15T8) sold at places like Amazon, so they are out there if you want to buy them. The prices for the LED's seem to run about 50 percent higher than the old fluorescent tubes.
Jim
American Locomotive
Well-known member
You sure? We are given the things all the time. We have 3 now.
ahh I thought 17 seemed an odd size...makes sense now.. Ive been to busy to look at it but definetly wanna get it working again... now wouldn't the f15t8 require a dif ballast? the f12? these aren't like modern day ballasts at all there more like transformers and strange looking caps... I believe I seen a stamp inside that said 1956
The electrical specs for both lamps are close enough that they can usually run off the same ballast. The ballast should actually run a bit cooler with the T8. The F15T8 is actually a very old lamp and doesn't really share anything with modern T8's. I think the F15T8 came before the F15T12.
These use a simple ballast, it is just a choke. They generally last just about forever.
Platonic Solid
Well-known member
It should have transformer and a starter that looks like this:
Edit: Above is incorrect - Please disregard and read on.
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Fibersport
Active member
My dad had one of those. If it is a Dazor, the company is still in business and it seems parts are still available, I just googled them.
rlitman
Well-known member
It is positively a Dazor. Nobody else made a lamp with that exact arm style.
You should look these up on eBay.
It should have transformer and a starter that looks like this:
Shouldn't have a starter. It has two buttons to turn it on and off, indicating that it's manual preheat. If the choke (transformer) is actually bad you can get 14/15/20 watt chokes for a dime a dozen, if you decide to go that route.
Platonic Solid
Well-known member
You are 100% correct - my error.
hey guys thanks for the info. I havnt had time to tear it open again... but what it has is 2 coils in the base that look like transformers and 2 things up at the switches (2 push buttons) which look like tubular capacitors I will try to open it up and take pics sometime next week. just that time of year when theres no time for anything!
well I tore into her and took some pics... caps don't look stretched? not sure how they could be tested? one coil is starting to unwind the cardboardy stuff that's wrapped around the coil is hard and chipping off . delaminating?...( its old) not sure how the coils work but a quick continuity test showed no current passing thru... either one of them? I look on this dazor site as someone above posted I don't see parts for sale on there? anyhow heres some pics maybe someone can tell me how to test out the coils and caps properly..theres nothing else to go wrong that I can see?
Attachments
The caps look like they are just for noise suppression (not important to the light working). If they aren't shorted I wouldn't worry about them at this point.
Those chokes (transformer/coil) rarely go bad but it you moved them around a lot without securing those leads it is possible the winding is broken. The continuity check you did should tell you, I'm assuming you checked between the two black leads? Also you may want to use the ohm setting, some multi-meters will show no continuity if there is over say 20 ohms resistance.
As I said before 14/15/20 watt chokes are cheap and they are not specific to danzor. You may not find one exactly the same shape as the old, but they are available.
Those chokes (transformer/coil) rarely go bad but it you moved them around a lot without securing those leads it is possible the winding is broken. The continuity check you did should tell you, I'm assuming you checked between the two black leads? Also you may want to use the ohm setting, some multi-meters will show no continuity if there is over say 20 ohms resistance.
As I said before 14/15/20 watt chokes are cheap and they are not specific to danzor. You may not find one exactly the same shape as the old, but they are available.
Platonic Solid
Well-known member
I'm not familiar with the switch with caps setup, but wouldn't you expect the caps to be functioning as a starting aid?
I just did a quick continuity check with my tester (testlight with built in battery) didn't do an ohm check as I don't have anything to compare it too.... neither of them showed continuity though...one has the wire pulled loose as seen in the pic...the other looks fine... seems the wraping material is pretty brittal on them though I will run an ohm meter next time im out there. bert what would be a good source for chokes? im not quite familiar with how a fluorescent works I believe somehow the choke makes a higher voltage to fire the bulb then it switches it back to line voltage (120 vac)
guessing that set up with 2 chokes uses one to preheat and fire the lamp as you press and hold the ON button and the other one, with the caps, to operate the lamp once it's fired. The caps keep the lamp at a steady rate and improve power factor.
Really old set up. The dazor that I took apart only had one choke to do the same thing. Unless you're going for an authentic restoration, I'd scrub all that stuff and go with one choke, like Advance LC1420C.
CD
Really old set up. The dazor that I took apart only had one choke to do the same thing. Unless you're going for an authentic restoration, I'd scrub all that stuff and go with one choke, like Advance LC1420C.
CD
This lamp takes (2) bulbs correct? That would explain the two chokes.
I can't say for sure from the picture but those caps really do look like they are just for noise suppression. I have a flexarm desk lamp without these caps and it will make a "blip" on the TV or radio when the lamp is turned on. It is also possible that the caps are for power factor correction but I have my doubts. I would be surprised if they affect the way the bulb works at all.
The main purpose of the choke is to regulate current. A fluorescent lamp does not have any resistance and much like an LED needs a constant current supply. You can think of it sort of like a big resistor. The choke cyberdyke suggested is a good option if yours are bad. The tester you are using might require more current that what the chokes will pass. Even if yours are good the tester may not light or light dimly.
One question, when you had the lamp put together and tried to test it. Did you hold the red button for several seconds? That is necessary to preheat the bulb.
As for the operation, somewhat simplified. This is how pretty much all of these desk lamps work. Yours will have double of some parts since it has two lamps (bulbs).
First you press the red button. Current flows though the filaments warming up the lamp.
After a few seconds you release the button and the sudden stop of current though the choke makes an "inductive kick" (google if you don't already know). That combined with the warm lamp is enough to start an arc across the lamp. Current flows though the lamp and there is light!
I can't say for sure from the picture but those caps really do look like they are just for noise suppression. I have a flexarm desk lamp without these caps and it will make a "blip" on the TV or radio when the lamp is turned on. It is also possible that the caps are for power factor correction but I have my doubts. I would be surprised if they affect the way the bulb works at all.
The main purpose of the choke is to regulate current. A fluorescent lamp does not have any resistance and much like an LED needs a constant current supply. You can think of it sort of like a big resistor. The choke cyberdyke suggested is a good option if yours are bad. The tester you are using might require more current that what the chokes will pass. Even if yours are good the tester may not light or light dimly.
One question, when you had the lamp put together and tried to test it. Did you hold the red button for several seconds? That is necessary to preheat the bulb.
As for the operation, somewhat simplified. This is how pretty much all of these desk lamps work. Yours will have double of some parts since it has two lamps (bulbs).
First you press the red button. Current flows though the filaments warming up the lamp.
After a few seconds you release the button and the sudden stop of current though the choke makes an "inductive kick" (google if you don't already know). That combined with the warm lamp is enough to start an arc across the lamp. Current flows though the lamp and there is light!
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Jim_No_Garage
Well-known member
I've never seen a switch with caps on it like that! I have a bunch of Dazors and a few Flexo's around here and have replaces switches and transformers to get old lights up and running.
Surplus Center used to have the switch for Flexo's in stock - not sure anymore. The transformers are cheap on Amazon and I think HD has them too.
Cheers
Jim
Surplus Center used to have the switch for Flexo's in stock - not sure anymore. The transformers are cheap on Amazon and I think HD has them too.
Cheers
Jim
well I finaly got back to it.. put it all together im thinking the chokes are ok since they both ohmed out the same...bulbs on the other hand. im gonna buy a new one if I can find the odd 17" size and see if that may be my issue... least get it back working with the flourescents as changing out to led didn't sound to do able
Just in case you forgot, this is not an odd size.
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new bulbs and away she went... thanks for the info guys and I had no clue it was a collectors item I just thought it was a relick... sprayed it machine grey to match the lathe much better looking then **** brown that someone had painted it. anyhow its back in service for another 50 plus years and now asbestos free ;p
I had a "hold to start" magnifier lamp. The three position (off-on-momentary start) switch bit the dust and it was hard to get a replacement so I installed a starter and replaced the switch with an on-off one. The fl. tubes last a long time. Rather than a conversion to LED I might just moderize it with an electronic ballast. You have have choice with color here, too. I pulled out the "daylight" circline that came with another magnifier and installed a 4100K, that I prefer.
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