Picked up a set of LED tubes for a shop florescent light fixture. Manufacturer states on package "Works with most ballasts". Well, not mine apparently - hums audibly moreso than the florescents and eventually trips the ballast breaker, which I assume is thermal.
I went through several cycles of use in this state, finially getting up the gumption to do something about it. Working solution uses one of my Variacs, set to "70" on the dial. A bit less light, but no longer trips the breaker. I have to put a step ladder atop a ping-pong table to access the fixture / tubes... AC socket were it plugs into is much more easily accessible.
Since I have two other Variacs on hand, I could let it sit for years that way, but was hoping for a less "hardware intensive" solution - like a series diode and capacitor maybe. The lamps being returned for a refund, or getting new lamps that work with the ballast I happen to have, are not viable solutions for me.
I suppose I could find a transformer with a 30 - 40V secondary and get away with bucking down the AC line to suit my predicament. Unsure what the current is, as my Variac doesnt have meters, but it would be possible to find out.
Any ideas that wont burn the shop down? Thanks!
I went through several cycles of use in this state, finially getting up the gumption to do something about it. Working solution uses one of my Variacs, set to "70" on the dial. A bit less light, but no longer trips the breaker. I have to put a step ladder atop a ping-pong table to access the fixture / tubes... AC socket were it plugs into is much more easily accessible.
Since I have two other Variacs on hand, I could let it sit for years that way, but was hoping for a less "hardware intensive" solution - like a series diode and capacitor maybe. The lamps being returned for a refund, or getting new lamps that work with the ballast I happen to have, are not viable solutions for me.
I suppose I could find a transformer with a 30 - 40V secondary and get away with bucking down the AC line to suit my predicament. Unsure what the current is, as my Variac doesnt have meters, but it would be possible to find out.
Any ideas that wont burn the shop down? Thanks!
Please post photos of the ratings on the ballasts and tubes.
There are different circuits on the tubes, 12, 24, 48 and 80V are common here.
The LEDs singly are usually 3.3V or so, but are in groups of LEDs in series with a resistor.
Since you have a problem with returning them, use a 1 milli Farad / >300V cap in series, and see what happens.
And sometimes they do get hot, I drill 3 mm holes (1/8") for ventilation, particularly at the power supply area.
You could strip one, and check the voltages.
Also, some have R-C networks instead of SMPS in the supply, and at times the supply has a poor heat sink, thermal cycling happens.
And some are (should be, really) constant current type supplies, you have to work that out.
R-C is a quick, cheap. inefficien but reliable solution, does not run hot, but how they got past US import conditions is a big question mark to me.
There are different circuits on the tubes, 12, 24, 48 and 80V are common here.
The LEDs singly are usually 3.3V or so, but are in groups of LEDs in series with a resistor.
Since you have a problem with returning them, use a 1 milli Farad / >300V cap in series, and see what happens.
And sometimes they do get hot, I drill 3 mm holes (1/8") for ventilation, particularly at the power supply area.
You could strip one, and check the voltages.
Also, some have R-C networks instead of SMPS in the supply, and at times the supply has a poor heat sink, thermal cycling happens.
And some are (should be, really) constant current type supplies, you have to work that out.
R-C is a quick, cheap. inefficien but reliable solution, does not run hot, but how they got past US import conditions is a big question mark to me.
Cant return.
Probably took life into own hands just to pop them into the fixture! No way I'm going back up there for that info, just because it presented its "little problem". Solution must be addressable at the AC mains socket, as in the series capacitor you suggested.
Thanks guys!
There is also the slight chance that they were known to be defective, and the shop found it easier to sell at a no responsibility / return price than ship them back to the maker.
The quailty of LED tubes has improved here, the earlier ones used to fail within two years, so the power saved was the same as cost of replacement.
For that reason, and low light output, I stick to fluorescent tubes, the big 1 1/2" ones, 40W, 2300 lumens typical.
The 20W units sold here were 1800 lumens, so dim in comparison.
Just saw a 28W unit at 115 lumens / Watt, 300 Rupees, $3.75 or so...that would be nice.
Now they are saying 2 kV surge protection, and use dedicated SMPS circuits, made on a large scale, one factory accross town makes 500k daily as OEM for people who are reputed, some say Philips and Crompton also buy in their brand from them.
In sum, the drivers have evolved from R-C to dedicated SMPS, so now at least they are reliable and EMI issues are adressed as well.
Try and put a capacitor type fan regulator in series, they have a switch, with different caps (1 to about 4.5, MPP or encapsulated like toffee), if you want to get the best performance, they are like 60 cents here....you can simply rotate the switch and see what happens, provided of course a single cap works.
The quailty of LED tubes has improved here, the earlier ones used to fail within two years, so the power saved was the same as cost of replacement.
For that reason, and low light output, I stick to fluorescent tubes, the big 1 1/2" ones, 40W, 2300 lumens typical.
The 20W units sold here were 1800 lumens, so dim in comparison.
Just saw a 28W unit at 115 lumens / Watt, 300 Rupees, $3.75 or so...that would be nice.
Now they are saying 2 kV surge protection, and use dedicated SMPS circuits, made on a large scale, one factory accross town makes 500k daily as OEM for people who are reputed, some say Philips and Crompton also buy in their brand from them.
In sum, the drivers have evolved from R-C to dedicated SMPS, so now at least they are reliable and EMI issues are adressed as well.
Try and put a capacitor type fan regulator in series, they have a switch, with different caps (1 to about 4.5, MPP or encapsulated like toffee), if you want to get the best performance, they are like 60 cents here....you can simply rotate the switch and see what happens, provided of course a single cap works.
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Looks like Naresh takes the cake; I found one stored with the bits from when I removed the ceiling fan from the living room, replacing it with a different light fixture some years ago.
Inside there's two Nichicon 350V film caps (even with bleed resistors) at 10 and a 5, so I assume the three speeds are 5, 10 and 15 uf in series with the AC line. The 10 selection seems most suitable - I dont need laser-bright out of that fixture. So I'll keep an eye out for a cap like that and let the speed control sit in place for now - better than the Variac!
Thanks!
I've changed the two fixtures in my shop over to use "direct wire" led tubes. Hot wire to one end of fixture, and neutral to the other end. Bad ballast removed. At work we've done the same with hundreds of 5 tube fixtures. The led tubes are cheaper than ballasts plus flourescent tubes... lower power consumption and slightly more light. My 2 cents.
Found this:
https://ledlightinginfo.com/do-led-bulbs-need-a-ballast
So it looks like the ballast becomes a ~problem when you use LED tubes. "Plug-and-play" LED tubes have a HV AC to DC conversion built in, but the ~best? solution is to just remove the ballast and wire the tubes directly to the line.
BTW, the ~5uF/10uF caps in a ceiling fan are the fan speed options.
Clearly florescent tubes and LEDs have drastically different voltage and current requirements, and it appears that vendors have created LED tubes with a lot of extra power conversion in order to make their LED tubes "plug-and-play", but it's ~wasteful so some LED may not bother, assuming you dump the ballast along with the fluorescent tubes. A traditional fluorescent ballast is a high voltage transformer with a lot of deliberate leakage inductance to limit the short circuit current.
https://ledlightinginfo.com/do-led-bulbs-need-a-ballast
So it looks like the ballast becomes a ~problem when you use LED tubes. "Plug-and-play" LED tubes have a HV AC to DC conversion built in, but the ~best? solution is to just remove the ballast and wire the tubes directly to the line.
BTW, the ~5uF/10uF caps in a ceiling fan are the fan speed options.
Clearly florescent tubes and LEDs have drastically different voltage and current requirements, and it appears that vendors have created LED tubes with a lot of extra power conversion in order to make their LED tubes "plug-and-play", but it's ~wasteful so some LED may not bother, assuming you dump the ballast along with the fluorescent tubes. A traditional fluorescent ballast is a high voltage transformer with a lot of deliberate leakage inductance to limit the short circuit current.
That's true for neon signs transformers.Domestic/garden varieties of luminescent/fluorescent tube simply uses an inductor as dropping impedance. Some sub-varieties intended for instant-start or quick-start tubes may include a small transformer section, but the main function remains inductive.
It is in principle possible to use a resistive ballast, but with a severe dissipation penalty. It is sometimes used for lower power tubes designed to generate specific wavelengths in scientific instruments.
A capacitive dropping impedance would look attractive, except that it results in chaos when combined with the negative resistance of a gas tube
The open circuit voltage of a fluorescent ballast is 600 to 800V but that may be for two tubes. In Europe where the line volage is 240V, it's not far away from 300V but here in North America, we run with a 120V line voltage. Even with heated electrodes, the gas tube needs a high ionization voltage, after which the tube impedance falls drastically leaving the ballast to limit the current.
I found this video, but he does not do the best job.
He would be smarter to use the yellow wires, but it works either way, and it probably doesn't matter which yellow/red/blue wire is hot or neutral. He does a good job of illustrating how easy this is, and extra points for including the trouble shooting when one didn't work first time. I worked (very) briefly with a fellow who did not have the patience and humility to check his wiring again.
I am a little concerned about how the line connects because connecting an old lamp that way would immediately blow out the (low voltage) heater.
I was tempted to install florescent fixtures in my garage ~20 years ago, but instead I opted for lamp Y-sockets to multiple CFLs and LED lamps. Today they sell very bright LED arrays that screw into a normal lamp socket.
https://www.amazon.com/KONPWAY-LED-...=01HFY6QA7Q8N1TT2Z879WGSZ46&tag=snx79-20&th=1
I found this video, but he does not do the best job.
I am a little concerned about how the line connects because connecting an old lamp that way would immediately blow out the (low voltage) heater.
I was tempted to install florescent fixtures in my garage ~20 years ago, but instead I opted for lamp Y-sockets to multiple CFLs and LED lamps. Today they sell very bright LED arrays that screw into a normal lamp socket.
https://www.amazon.com/KONPWAY-LED-...=01HFY6QA7Q8N1TT2Z879WGSZ46&tag=snx79-20&th=1