LED lights and dimmer switches

[Furcifer]

Now that the initial "fear, uncertainty, & doubt" since the Rule change has passed , will you post a link for that, please?

Here's the one I've used in the past: http://www.buyincoins.com/ir-remote-control-controller-for-5050-smd-rgb-led-strip-product-2456.html
You can pick them up on eBay for even less if you have a little patience. I took off the 4 pin connector and soldered on some 18 gauge wire. Then you can basically run 3 LED's off the one unit. At 9A that's a lot of LED. You can also get a DC power supply from the Dollar Store if you don't have one lying around.
And there's your dimmer +more. Not having DC power makes it a little more cumbersome but it's still inexpensive.
These RGB light bulbs:http://cgi.ebay.ca/3W-E27-RGB-led-Spotlight-Bulb-16-colors-IR-remote-/250824915511?pt=Lamps_US&hash=item3a66547a37 might have more potential because they have the AC to DC already in the base. I just haven't taken one apart yet.

 

[Furcifer]

Perhaps you should do some investigation before mocking the statements of others. The primary reason LEDs have taken so long to become viable for household use (costs aside) is because they generate too much heat, particularly when used in recessed fixtures. While not necessarily 'hot' to the touch like incandescents or halogens, this significantly impacts the useful lifespan of the bulbs. This is why all LED bulbs and other high-wattage LEDs come with heat sinks, and only recently reached a point where they could be effectively used in recessed fixtures.

This is exactly correct. macdoc hasn't done the math, the LED's we've been talking about aren't 3W, the XM-L is running at ~12W and if memory serves the SST-90's are running at ~40W! The 50W mark is coming in the very near future.
Only recently I've seen these high temperature plastic reflectors that "snap" onto the emitter, making them ideal of recessed lighting. And not for the XM-L but the XP-G. They put out about the same light at 1.5A (20% difference), but the XM-L can be driven up to 3A, that makes it considerably hotter. The XM-L is boasting 120lm/watt to put that into perspective an incandescent gets less than 20lm/watt.

 

[CaveDave]

Here's the one I've used in the past: http://www.buyincoins.com/ir-remote-control-controller-for-5050-smd-rgb-led-strip-product-2456.html
You can pick them up on eBay for even less if you have a little patience. I took off the 4 pin connector and soldered on some 18 gauge wire. Then you can basically run 3 LED's off the one unit. At 9A that's a lot of LED. You can also get a DC power supply from the Dollar Store if you don't have one lying around.
And there's your dimmer +more. Not having DC power makes it a little more cumbersome but it's still inexpensive.
These RGB light bulbs:http://cgi.ebay.ca/3W-E27-RGB-led-Spotlight-Bulb-16-colors-IR-remote-/250824915511?pt=Lamps_US&hash=item3a66547a37 might have more potential because they have the AC to DC already in the base. I just haven't taken one apart yet.

Pretty SNAZZY, cool.

That Edison base spotlight, especially!

I can tell by the input voltage range that it probably uses an accross-the-line switchmode power supply, and the functional modes list makes me confident that it was designed similarly to the way I said I would do it.

ETA:IOW, using a microcontroller and PWM drivers for each output.

I wouldm love to open one and see...

Not too shabby on those prices, either.

Cheers,

Dave

 

[Myriad]

Yah eh? I just recently got interested in the LED flashlights (I call them torches now, something primitive about it ), but it's my understanding from what I've read over at the candle power forum that this is fairly reasonable for a torch. Some of the torches are upwards of $600! I've got a limit of $25. These days however $25 get you one heck of a torch. Not 2300 lumen mind you, but 1000 lumen is good enough for me.

Where can you get a 1000 lumen flashlight for anywhere close to $25? I'd love to get some, I've been getting by with a 100 lumen one (though with a thick glass focusing lens that makes it very versatile) that retailed around $40 a few years ago.

Respectfully,
Myriad

 

[Dr. Trintignant]

Either you are exaggerating, or you are buying really bad incandescent bulbs. I have a number of incandescents that that have lasted over ten years at low duty (closet lights) and others that I have only replaced 2 to 3 times in 13 years at medium duty (so call it 4 to 6 years life).

Standard incandescents are rated at 1000 hours. That's 5.5 hrs per day for half a year. Seems like pretty typical usage for room lights; might even be on the low side depending on the time of year, latitude, bedtime, etc.

- Dr. Trintignant

 

[Furcifer]

Where can you get a 1000 lumen flashlight for anywhere close to $25? I'd love to get some, I've been getting by with a 100 lumen one (though with a thick glass focusing lens that makes it very versatile) that retailed around $40 a few years ago.

Respectfully,
Myriad

I like this one, it has the bigger reflector :LM C8

There are a couple Ultrafire 501's for about $18 on that site that will do ~1000 lumen. The manfuacturer ratings tend to overestimate the lumen output. An XM-L with 3A to the leads will do ~1140 lumen. Theoretically.

Be prepared to move to 18650 Li-ion batteries though. I've got an XM-L adapted to run 3S1P AAA's and it gets about 20 minutes of run time on high.

Heat's an issue and these inexpensive 1000 lumen flashlights still using the P60 drop ins require some additional heat sinking. I use a copper based permatex gasket silicone but most people use CPU heatsink paste.

ETA: To do 1000 lumen you really need 18650's or CR123A's. If you really want to stay with AA's look for a 350 Lumen XP-G based flashlight ($12 will get you a good one). That's about as bright as you want a flashlight running Ni-Mh or Alkaline batteries. I've noticed the XP-G based flashlights run very close to what they are rated at (I think alkaline and Ni-mh batteries have less internal resistance than Li-ion and as such in a direct drive mode really push the amps, I could be wrong though). 350-400 lumen is surprisingly bright coming from something the size of a roll of Lifesavers.

 

[Dr. Trintignant]

I like this one, it has the bigger reflector :LM C8

The specs on that flashlight are... strange. It says "3.7V~800mA,4.2V~710mA"--in other words, just about 3 watts. But according to this, reaching 1000 lm on the T6 requires 357% (1000/280) of the base level, and needs >3 A of current. At this current level the voltage drop is 3.35, so over 10 watts (and that still only gets you to 910 lumens). 3 watts seems to only get you to around 385 lumens (though that's still pretty impressive for a $24 flashlight).

- Dr. Trintignant

 

[elgarak]

The specs on that flashlight are... strange. It says "3.7V~800mA,4.2V~710mA"--in other words, just about 3 watts. But according to this, reaching 1000 lm on the T6 requires 357% (1000/280) of the base level, and needs >3 A of current. At this current level the voltage drop is 3.35, so over 10 watts (and that still only gets you to 910 lumens). 3 watts seems to only get you to around 385 lumens (though that's still pretty impressive for a $24 flashlight).

- Dr. Trintignant

Indeed. These cheap (usually chinese) products and vendors quite often list the highest number they find in the datasheets, with complete disregard what the actual LED is driven at, or what comes out the front of the flashlight.

The "385 lumens" seems to be pretty close to what the LED will put out if the electrical values are correct (why should they, if they even lie about the lumens?); if it actually comes out the front of the light, is another question. Depends on how well the LED is fitted into the reflector, its reflectance and what transmission the front lens has (as usual, one cannot reach 100% efficiency). In my experience, you can easily estimate 50% to 75% of this is actually coming out the front (~200..290 lumens). That's still pretty good, but a far cry from "1000".

 

[Furcifer]

The specs on that flashlight are... strange. It says "3.7V~800mA,4.2V~710mA"--in other words, just about 3 watts. But according to this, reaching 1000 lm on the T6 requires 357% (1000/280) of the base level, and needs >3 A of current. At this current level the voltage drop is 3.35, so over 10 watts (and that still only gets you to 910 lumens). 3 watts seems to only get you to around 385 lumens (though that's still pretty impressive for a $24 flashlight).

- Dr. Trintignant

The Chinese websites are notoriously bad at giving the proper specs. I just checked several other models and they give the same specs. The XM-L emitter forward voltage at 700ma is 2.9V and 3.35V at 3000ma.

There are only a few drivers on the market. It's either running at 2.8A or 3A, probably 2.8A, which they like to say is 1000 lumen. When they use the 3A driver you'll see 1300 lumen, which isn't even possible with the newest U2 bin LED. With a light meter and a little math you can calculate the actual lumen. If I had to guess it's probably ~800 lumen OTF.

 

[Furcifer]

In my experience, you can easily estimate 50% to 75% of this is actually coming out the front (~200..290 lumens). That's still pretty good, but a far cry from "1000".

If it's using an old 1400ma driver that's probably correct. I suspect it's got the 2.8A driver. That's what they were using with the SSC P7 LED which was the last high power LED prior to the XM-L. The company probably has a whack of them.
Brightness is a hard thing to measure. It depends on the reflector and the lens as well as the emitter.

ETA: but yah, 50% is a safe bet. I bought another off eBay they claimed was 800lm, with an XP-G emitter. The XG-G over driven, (which I think it is because the flashlight overheats) can't do 800lm. At 1.5A I think it's rated at 493lm.

 

[Furcifer]

Pretty SNAZZY, cool.

That Edison base spotlight, especially!

I can tell by the input voltage range that it probably uses an accross-the-line switchmode power supply, and the functional modes list makes me confident that it was designed similarly to the way I said I would do it.

ETA:IOW, using a microcontroller and PWM drivers for each output.

I wouldm love to open one and see...

Not too shabby on those prices, either.

Cheers,

Dave

I think your other option would be to get something like this: http://cgi.ebay.ca/LED-Driver-Circuit-Input-85-265V-AC-New-/190537831828?pt=LH_DefaultDomain_0&hash=item2c5cf09594

I think this will work with a traditional dimmer switch. It won't work with any of the LED's I've mentioned here, 20V is too high for a direct drive and none of the driver's I've seen will take 20V. The CXA2011 LED from CREE operates at 40V. If you found one of these that operates at 40V, $7 plus $16 for the emitter is a very inexpensive. At 5 times the efficiency of an incandescent, in a high use area this would pay for itself in no time.

I prefer going the IR remote way myself. I think they offer a 20V model so it would also work in line with this AC driver.

 

[CaveDave]

I think your other option would be to get something like this: http://cgi.ebay.ca/LED-Driver-Circuit-Input-85-265V-AC-New-/190537831828?pt=LH_DefaultDomain_0&hash=item2c5cf09594

I think this will work with a traditional dimmer switch. It won't work with any of the LED's I've mentioned here, 20V is too high for a direct drive and none of the driver's I've seen will take 20V. The CXA2011 LED from CREE operates at 40V. If you found one of these that operates at 40V, $7 plus $16 for the emitter is a very inexpensive. At 5 times the efficiency of an incandescent, in a high use area this would pay for itself in no time.

I prefer going the IR remote way myself. I think they offer a 20V model so it would also work in line with this AC driver.

You only need to take two of the 20 V units, connect the outputs in series, and PRESTO, 40 V @ the same current!
(Making the assumption that these parts are life-safety Standards compliant [I don't know, because there was not enough specifications given], and are internally FULLY isolated from the mains, which is normally done with any product.)

Cheers,

Dave

 

[Myriad]

I like this one, it has the bigger reflector :LM C8

There are a couple Ultrafire 501's for about $18 on that site that will do ~1000 lumen. The manfuacturer ratings tend to overestimate the lumen output. An XM-L with 3A to the leads will do ~1140 lumen. Theoretically.

Be prepared to move to 18650 Li-ion batteries though. I've got an XM-L adapted to run 3S1P AAA's and it gets about 20 minutes of run time on high.

Heat's an issue and these inexpensive 1000 lumen flashlights still using the P60 drop ins require some additional heat sinking. I use a copper based permatex gasket silicone but most people use CPU heatsink paste.

ETA: To do 1000 lumen you really need 18650's or CR123A's. If you really want to stay with AA's look for a 350 Lumen XP-G based flashlight ($12 will get you a good one). That's about as bright as you want a flashlight running Ni-Mh or Alkaline batteries. I've noticed the XP-G based flashlights run very close to what they are rated at (I think alkaline and Ni-mh batteries have less internal resistance than Li-ion and as such in a direct drive mode really push the amps, I could be wrong though). 350-400 lumen is surprisingly bright coming from something the size of a roll of Lifesavers.

Thanks for the info, 3bodyproblem (and the follow up posters). Those are some interesting leads.

My lensed flashlight uses AAA's and is more than adequate for traditional flashlight applications. (By lensed, I mean the front "lens" really is a lens rather than just a flat piece of glass covering the emitter, which makes the spot really even -- as even as a focused theater Leko, as far as I can tell -- and also zoomable between tight and wide beams. I got it at a Lowe's with different retail packaging but I think it's this one: http://www.ledlenser.com/US/products/html_highperformance/html_Lseries/l7.php?id=l7). So, I don't mind if my next purchase needs the 18650s or CR123A's.

On the other hand, I'd rather it be functional out of the box without cooking itself in normal use if you don't bolt metal plates onto it or something. And I want high output, at least 800 lumens out the front at the high-power steady (not momentary-on) setting. So maybe I'll wait for the case designs to catch up with the emitters, or plan to spend a bit more.

By the way: Google "18,000 lumens" for stories and videos on a cool floodlight that uses 18 XM-L's in a case that looks like a prop from ST:TNG. It can't be called a flashlight or torch by any stretch of the definition, but it does run on batteries. (It doesn't seem to be in production yet.)

Respectfully,
Myriad

 

[Furcifer]

Thanks for the info, 3bodyproblem (and the follow up posters). Those are some interesting leads.

My lensed flashlight uses AAA's and is more than adequate for traditional flashlight applications. (By lensed, I mean the front "lens" really is a lens rather than just a flat piece of glass covering the emitter, which makes the spot really even -- as even as a focused theater Leko, as far as I can tell -- and also zoomable between tight and wide beams. I got it at a Lowe's with different retail packaging but I think it's this one: http://www.ledlenser.com/US/products/html_highperformance/html_Lseries/l7.php?id=l7). So, I don't mind if my next purchase needs the 18650s or CR123A's.

On the other hand, I'd rather it be functional out of the box without cooking itself in normal use if you don't bolt metal plates onto it or something. And I want high output, at least 800 lumens out the front at the high-power steady (not momentary-on) setting. So maybe I'll wait for the case designs to catch up with the emitters, or plan to spend a bit more.

By the way: Google "18,000 lumens" for stories and videos on a cool floodlight that uses 18 XM-L's in a case that looks like a prop from ST:TNG. It can't be called a flashlight or torch by any stretch of the definition, but it does run on batteries. (It doesn't seem to be in production yet.)

Respectfully,
Myriad

I've noticed that the shape and size of the LED also plays significant part in whether the LED is a "thrower" ie. a tight focused beam or a "flooder" a wide more diffused beam.
The aspherical lens on your current flashlight is more closely approximated by the XP-G LED. It's a tiny LED, smaller than the MC-E or XM-L and much smaller than the SSC P7, and has a very tight "throwy" beam. An "older" LED the price has come down considerably and XP-G based lights can be found for as little as ~$14, and running at most 1.5A have less problems over heating and battery life. I highly recommend this LED with a smooth reflector if you want a small light that will do things like light up the street numbers on a house.
Even 400 lumen is extremely bright. Some people find the new LED's too bright, turning them on "hi" at night can cause night blindness as your eyes adjust. At the same time the "low" function may not be bright enough. These days it's actually important to consider what type of application you intend to use the flashlight for and perhaps not buy the brightest flashlight, they're really that bright.
(of course ever one I've got was as bright as I could get for the money )

People should know that the days of the LED lights that looks like a shower head covered in plastic beads is over. As you've mentioned, something with 20 XM-L LED's gets hot enough to cook a Christmas turkey and could signal passing jet liners.

 

[Furcifer]

You only need to take two of the 20 V units, connect the outputs in series, and PRESTO, 40 V @ the same current!
(Making the assumption that these parts are life-safety Standards compliant [I don't know, because there was not enough specifications given], and are internally FULLY isolated from the mains, which is normally done with any product.)

Cheers,

Dave

And you'd have upwards of 5000 lumen to play with!