Shop Lighting Commentary

[Blackjackjacques]

Today's LEDs are incredible and pretty much rendered incandescent bulbs obsolete. One advantage provided by conventional incandescent bulbs was the low temperature color. LEDs do offer low temp (2400K , etc) but more often than not, you will see 4000K. The advantage of the low temp bulbs, leaning towards the red versus the high temperature blue, is that the pupil is less sensitive to the lower temperature and stays open wide, while the blues will cause the aperature to contract. While there is perhaps greater contrast with the higher temperature, the pupil will let less light in. So you have a bit of a trade off. I use the low temp LEDS for general indoor illumination (along with yellow walls and white ceiling) and where I will be working for long durations, reading, computer, work bench - however, I may supplement with a slightly hotter task light where needed - say perhaps when working with small parts. I also notice that my forehead seems more relaxed (scrunching from glare) with the low temps over the high temps, and I can perhaps delay the need for Botox treatment. I like the 4000K for outdoor flood lighting, say motion detection ltg at a distance.

 

[magu]

As purchased, my garage had 1 hanging incandescent (and no outlets... seriously, none), I didn't want to go the tube florescent route because I really like the beam construction of the roof, and didn't want to obscure it more than necessary. I bought two of these: Hypericon LED floodlight and have been really happy with the one I have installed thus far.

 

[ACHiPo]

As purchased, my garage had 1 hanging incandescent (and no outlets... seriously, none), I didn't want to go the tube florescent route because I really like the beam construction of the roof, and didn't want to obscure it more than necessary. I bought two of these: Hypericon LED floodlight and have been really happy with the one I have installed thus far.


View attachment 248347

Wow that's pretty darned bright! Bet it makes for some long shadows?

 

[magu]

Wow that's pretty darned bright! Bet it makes for some long shadows?

Yeah, that's an unavoidable downside. It's still worlds better than anything I've had before lol. I have one more I plan on putting in the corner that is out of view to the left. Ideally, I'd like to get two more and put one in each corner.

 

[RJSakowski]

The comparison of low temperature vs. high temperature LED lighting is interesting. I personally prefer the 27000K or 3000K LED's for living spaces but I use the 4000K lighting for work areas.

Most of us us are old enough to remember a world where incandescent lighting was predominant. Some may even be old enough to have lived with kerosene lamps. We became accustomed the warmer tones illuminated by those sources. I have heard many people complain about the "glare" coming from fluorescent fixtures.

It parallels the complaint about the harsh sound of digital music, in comparison with the "natural" sound of vinyl with all of the hum, wow, flutter and narrow bandwidth even though digital music is technically a more accurate rendition.

There is one factor about LED lighting though. "white" light can be generated in two ways. Red, green, and blue light made up the white light seen on our old CRT monitors. However there is no yellow in that spectrum. Nor many of the other hues. Combining those three colors in various proportions makes up all the remaining colors by our perception.

White LED's are basically fluorescent devices which use the blue LED plus a yellow phosphor and a smattering of othe phosphors to make up what we perceive as white light. They are not providing an accurate rendition of true color though. The metric that they use to describe this ability to accurately render color is the CRI or color rendition index. A perfect render would be 100 but most white LED's fall in the 65 to 85 range.

Sunlight and incandescent bulbs, on the other hand are full spectrum light sources. All wavelengths in the visible spectrum are represented. An incandescent bulb works on the basis of radiation from a heated body and the curve favors the red over the blue portion of the spectrum which is why there is a warm yellowish tone. Sunlight is also radiation from a heated body but in its case the temperature is around 10,000ºC and the light appears more bluish.

 

[magu]

lol, some of you folks are making me forget which forum I'm on. Another passion of mine is reef keeping and lighting is the biggest factor and topic of discussion in that world: "how to replicate the sun on another part of the globe in a little box in your living room without owning your own nuclear reactor"

 

[gaston]

replaced all my worn out 4 footers with leds from amazon 24 bulbs with tomeones 177.00 , (7.68$ ea) do iy easy install (rewire one end, wack out the ballasts install new tubes allmost a no brainer

 

[uncle harry]

I don't believe that the old ballasts are thousands of volts. Their function is to limit the current in the tube. The starting circuit heats a filament to vaporize the mercury and start current flow in the tube. It switches out when the tube fires. I haven't measured actual voltage supplied to the tube so I can't say anything definitive about it. HF lights may be a different kettle of fish. They do not use the starter circuit. I have never measured voltage on those either. From the description of the LED Supply lamp, they give about a 30% increase in efficiency over the fluorescent fixture. I would expect the fluorescent manufacturers would spec. overall efficiency as would concerned energy conservationists. If that is the case. the quoted values are in line with what I would expect. (fluorescent's have about an 80-90lumen/watt efficiency, cool white LED's about 100-140 lumen/watt). I would expect that the drop-in replacements have a switching type driver and are able to accommodate a fairly wide range of voltages. I would call them up and ask. They have very knowledgeable tech support.

If I were going to build my own, I would use the 12 volt strips instead. You can use the fixture as the base. Strip out the guts of the old fluorescent fixture. Use an aluminum strip for mounting. You can also mount directly to the fixture but the impairs any future maintenance. Purchase a suitable switching power supply. DigiKey right in your back yard is a good source is Jameco in California. We machinsts are very capable of making any required mountings, adapters, etc. I did bounce lighting in our kitchen with a double row of these strip lights and it does an excellent job.

For alternatives, there are some interesting LED's out there. I have a couple of CXA 1310's that will put out almost 2000 lumens from a single 6mm disk. The cost was reasonable, under $10 as I recall. I purchased a LuxDrive 700 ma Flexblock for driving them. In terms of $/lumen, probably about as good as you will find. We have the automotive headlighting technology to thank for that. The big problem with these is that they are blindingly bright. For area lighting, you would need to design some sort of diffuser.

Bob

The classic starter fluorescents connect the end filaments in series through the single winding of the ballast.upon starting. This heats the filaments which are coated with chemical oxides that are very efficient in emitting electrons. The starter uses a bi-metal switch that gets hot and opens the series circuit. This bi-metal switch in encapsulated in a glass envelope which is filled with a rare gas, argon, which glows and keeps the bi-metal switch heated and open. When the switch opens, the inductive ballast's magnetic field collapses rapidly thus producing an inductive spike of very high voltage which initiates conduction through the the argon/mercury in the tube and permits using line voltage to produce UV radiation which excites the internal phosphors thus producing light. Thousands of volts are employed when powering neon signs and has been provided by core & coil transformers like those used in classic oil burner furnaces. The newer neon power technology use solid state transformers that run at 20,000 hertz to produce the high voltage.

 

[Blackjackjacques]

Wow that's pretty darned bright! Bet it makes for some long shadows?

I think that is the camera flash - which in itself is pretty impressive given the dark surfaces.

 

[silence dogood]

The comparison of low temperature vs. high temperature LED lighting is interesting. I personally prefer the 27000K or 3000K LED's for living spaces but I use the 4000K lighting for work areas.

Most of us us are old enough to remember a world where incandescent lighting was predominant. Some may even be old enough to have lived with kerosene lamps. We became accustomed the warmer tones illuminated by those sources. I have heard many people complain about the "glare" coming from fluorescent fixtures.

It parallels the complaint about the harsh sound of digital music, in comparison with the "natural" sound of vinyl with all of the hum, wow, flutter and narrow bandwidth even though digital music is technically a more accurate rendition.

There is one factor about LED lighting though. "white" light can be generated in two ways. Red, green, and blue light made up the white light seen on our old CRT monitors. However there is no yellow in that spectrum. Nor many of the other hues. Combining those three colors in various proportions makes up all the remaining colors by our perception.

White LED's are basically fluorescent devices which use the blue LED plus a yellow phosphor and a smattering of othe phosphors to make up what we perceive as white light. They are not providing an accurate rendition of true color though. The metric that they use to describe this ability to accurately render color is the CRI or color rendition index. A perfect render would be 100 but most white LED's fall in the 65 to 85 range.

Sunlight and incandescent bulbs, on the other hand are full spectrum light sources. All wavelengths in the visible spectrum are represented. An incandescent bulb works on the basis of radiation from a heated body and the curve favors the red over the blue portion of the spectrum which is why there is a warm yellowish tone. Sunlight is also radiation from a heated body but in its case the temperature is around 10,000ºC and the light appears more bluish.

GE puts out a LED fixture that is called "Enbrighten". Basically, it has two sets of LEDs, one for a cool and the other for warm. A switch can set it for one or the other or both. I mounted one above my lathe and leave it on the daylight (both LEDs) because I can see my work better. I even got one for my wife for her sewing.