Red LS DD?
- Thread starter ResQTech
- Start date
NewsFlash
Enlightened
MTFD17,
Not exactly. I am working on an amber DD with resistance with 1x123 light myself. Doing the mod thing with an E2e bezel, Esink and Ecan.
Will probably take 7-10 days before it's finished, will let you know how it goes. I did have a white KL1 so I know a little bit about how to compare the two. /ubbthreads/images/graemlins/blush.gif
Not exactly. I am working on an amber DD with resistance with 1x123 light myself. Doing the mod thing with an E2e bezel, Esink and Ecan.
Will probably take 7-10 days before it's finished, will let you know how it goes. I did have a white KL1 so I know a little bit about how to compare the two. /ubbthreads/images/graemlins/blush.gif
Well i have a gutted KL1 and i want a red LS in there. The circuit's shot, so i was just wondering how well a red LS would perform (brightness & runtime) running straight off a single 123, instead of running through the stock KL1 circuit.
NewsFlash
Enlightened
MTFD17,
Well, I haven't done much at all toward the above mentioned project. Today I did bite the bullet and ran an amber HD LS direct drive on 1x123 without resistance. This was with a SureFire cell. I put the LS on a heavy duty heatsink with thermal grease. Got everything hooked up and...
Got 140ma! I would have figured more, but the forward voltage is keeping it from going sky high, AFAIK. I would use caution, using some resistance first, unless you have already tried it DD with no ill effects.
Let's see. Figuring about 1220mah for a SureFire cell (based on a thread by batterystation), that comes to about 8.7 hours! Your mileage may vary.
I do believe it will make a nice light in an E2e bezel with Esink and Ecan. /ubbthreads/images/graemlins/wink.gif
Well, I haven't done much at all toward the above mentioned project. Today I did bite the bullet and ran an amber HD LS direct drive on 1x123 without resistance. This was with a SureFire cell. I put the LS on a heavy duty heatsink with thermal grease. Got everything hooked up and...
Got 140ma! I would have figured more, but the forward voltage is keeping it from going sky high, AFAIK. I would use caution, using some resistance first, unless you have already tried it DD with no ill effects.
Let's see. Figuring about 1220mah for a SureFire cell (based on a thread by batterystation), that comes to about 8.7 hours! Your mileage may vary.
I do believe it will make a nice light in an E2e bezel with Esink and Ecan. /ubbthreads/images/graemlins/wink.gif
BentHeadTX
Flashlight Enthusiast
Red LS,
I built a 2D Mag with a red LS for a friend of mine and checked it out. With a one ohm resistor, it will pull 475mA from two D cells (measured 1.615 volts no load) I would use a one ohm in line and check the mA drawn off the 123 battery.
My next mod reguarding red Luxeons is using a one AA Dorcy 3 LED light. It might pull around 250mA which would be enough for me. Now if the local Wal-Mart will ever get them in stock.
I built a 2D Mag with a red LS for a friend of mine and checked it out. With a one ohm resistor, it will pull 475mA from two D cells (measured 1.615 volts no load) I would use a one ohm in line and check the mA drawn off the 123 battery.
My next mod reguarding red Luxeons is using a one AA Dorcy 3 LED light. It might pull around 250mA which would be enough for me. Now if the local Wal-Mart will ever get them in stock.
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NewsFlash
Enlightened
BentHeadTX,
Was that red LS low dome or high dome? That will affect the forward voltage. Typical vf of low domes is 2.85v while typical vf of high domes is 2.95v. I believe also that the voltage drop on 1x123 (with a load) is greater than that of 2D's. I can get more current out of an amber HD LS with 2AA's direct drive than I can with 1x123, I can't remember the exact value that I got.
MTFD17 ,
I don't think a DD red LS will be anywhere near as bright as a KL1 red LS but the runtime should be much longer. Again, whether it's a low dome or high dome will affect your current and runtime, YMMV. /ubbthreads/images/graemlins/wink.gif
Was that red LS low dome or high dome? That will affect the forward voltage. Typical vf of low domes is 2.85v while typical vf of high domes is 2.95v. I believe also that the voltage drop on 1x123 (with a load) is greater than that of 2D's. I can get more current out of an amber HD LS with 2AA's direct drive than I can with 1x123, I can't remember the exact value that I got.
MTFD17 ,
I don't think a DD red LS will be anywhere near as bright as a KL1 red LS but the runtime should be much longer. Again, whether it's a low dome or high dome will affect your current and runtime, YMMV. /ubbthreads/images/graemlins/wink.gif
I'm driving a HD red-orange (same die, different binning) DD off 2C cells for about 380mA.
The vF of a red/r-o/amber LS will increase dramatically if you attempt to push more current through it - to the point where you will actually push less current through one DD on 3 cells than you would with a white/blue/green LS.
The vF of a red/r-o/amber LS will increase dramatically if you attempt to push more current through it - to the point where you will actually push less current through one DD on 3 cells than you would with a white/blue/green LS.
BentHeadTX
Flashlight Enthusiast
Newsflash,
The one I built was a red low dome, I guess that is why it needed the extra resistance. A half-ohm would be good for the high dome I guess, the mA meter has the final say!
The one I built was a red low dome, I guess that is why it needed the extra resistance. A half-ohm would be good for the high dome I guess, the mA meter has the final say!
NewsFlash
Enlightened
BentHeadTX,
Yes, the meter does doesn't it! /ubbthreads/images/graemlins/icon15.gif /ubbthreads/images/graemlins/grin.gif
evan9162 ,
I am confused. I would have thought 3 cells DD would fry a red/r-o/amber LS. I was thinking that up to a point, an increase in voltage will let you increase the amount of current. I used 2AA's at 2.87 volts DD and got 107ma. I used another set of 2AA's at 2.90 volts DD and got 167ma, both sets were the same brand, same package and slightly used. Past the maximum voltage input for a particular LS and I thought it would want to fry depending on the batteries and internal resistance.
Yes, the meter does doesn't it! /ubbthreads/images/graemlins/icon15.gif /ubbthreads/images/graemlins/grin.gif
evan9162 ,
I am confused. I would have thought 3 cells DD would fry a red/r-o/amber LS. I was thinking that up to a point, an increase in voltage will let you increase the amount of current. I used 2AA's at 2.87 volts DD and got 107ma. I used another set of 2AA's at 2.90 volts DD and got 167ma, both sets were the same brand, same package and slightly used. Past the maximum voltage input for a particular LS and I thought it would want to fry depending on the batteries and internal resistance.
[ QUOTE ]
NewsFlash said:
evan9162 ,
I am confused. I would have thought 3 cells DD would fry a red/r-o/amber LS. I was thinking that up to a point, an increase in voltage will let you increase the amount of current. I used 2AA's at 2.87 volts DD and got 107ma. I used another set of 2AA's at 2.90 volts DD and got 167ma, both sets were the same brand, same package and slightly used. Past the maximum voltage input for a particular LS and I thought it would want to fry depending on the batteries and internal resistance.
[/ QUOTE ]
Check out this post in an old thread about 3W luxeons:
http://www.candlepowerforums.com/ubbthreads/showthreaded.php?Cat=&Board=UBB3&Number=325923&page=&view=&sb=5&o=&vc=1
highlandsun ran a red and white off the same Li-Ion battery (not at the same time). The white drew a lot more current. My explanation of what is happening is the next post.
NewsFlash said:
evan9162 ,
I am confused. I would have thought 3 cells DD would fry a red/r-o/amber LS. I was thinking that up to a point, an increase in voltage will let you increase the amount of current. I used 2AA's at 2.87 volts DD and got 107ma. I used another set of 2AA's at 2.90 volts DD and got 167ma, both sets were the same brand, same package and slightly used. Past the maximum voltage input for a particular LS and I thought it would want to fry depending on the batteries and internal resistance.
[/ QUOTE ]
Check out this post in an old thread about 3W luxeons:
http://www.candlepowerforums.com/ubbthreads/showthreaded.php?Cat=&Board=UBB3&Number=325923&page=&view=&sb=5&o=&vc=1
highlandsun ran a red and white off the same Li-Ion battery (not at the same time). The white drew a lot more current. My explanation of what is happening is the next post.
NewsFlash
Enlightened
evan9162 ,
What a great explanation!
You know, come to think of it, 3 or 4 days ago I hooked up 1x123 cell with a 1ohm 1w resistor (from Elektrolumens) and now that my memory has been jogged, seems like I was getting about 240ma (I could be wrong). I then tried 2, then 3 1ohm 1w resistors in parallel to bring the resistance on down, and the current didn't vary much at all.
That seems so ironic that I would need to put resistance in the circuit to get more current to flow in the circuit. Isn't this what your dynamic resistance explanation is saying? /ubbthreads/images/graemlins/icon15.gif /ubbthreads/images/graemlins/grin.gif
What a great explanation!
You know, come to think of it, 3 or 4 days ago I hooked up 1x123 cell with a 1ohm 1w resistor (from Elektrolumens) and now that my memory has been jogged, seems like I was getting about 240ma (I could be wrong). I then tried 2, then 3 1ohm 1w resistors in parallel to bring the resistance on down, and the current didn't vary much at all.
That seems so ironic that I would need to put resistance in the circuit to get more current to flow in the circuit. Isn't this what your dynamic resistance explanation is saying? /ubbthreads/images/graemlins/icon15.gif /ubbthreads/images/graemlins/grin.gif
Not really. You'll never get more current by adding resistance. By adding resistors in parallel, you were actually lowering resistance.
Since the voltage of a 123 is so close to the Vf of a red luxeon, adding 1ohm of resistance will drop the current only slightly. By removing that resistor (or at least, making that resistance smalller, by adding resistors in parallel), you increase the current slightly. The Vf of the luxeon will go up, but also, the terminal voltage of the battery will drop more under load...eventually, by reducing the resitance, the Vf of the luxeon and the terminal voltage of the battery under load will meet.
The current you get under direct drive depends on the dynamic resistance of the luxeon, and the internal resistance of your power source. A higher dynamic resistance will mean that your Vf will be higher at a given current. A higher internal resistance for your power source means its terminal voltage will drop more for a given load.
The internal resistance of most batteries increases as they become discharged.
Since the voltage of a 123 is so close to the Vf of a red luxeon, adding 1ohm of resistance will drop the current only slightly. By removing that resistor (or at least, making that resistance smalller, by adding resistors in parallel), you increase the current slightly. The Vf of the luxeon will go up, but also, the terminal voltage of the battery will drop more under load...eventually, by reducing the resitance, the Vf of the luxeon and the terminal voltage of the battery under load will meet.
The current you get under direct drive depends on the dynamic resistance of the luxeon, and the internal resistance of your power source. A higher dynamic resistance will mean that your Vf will be higher at a given current. A higher internal resistance for your power source means its terminal voltage will drop more for a given load.
The internal resistance of most batteries increases as they become discharged.
NewsFlash
Enlightened
I redid my test with 1x123 cell and an amber HD LS. I had converted an old 2AA battery holder to use a 123 cell by using a couple of screws and a washer. This undoubtedly was putting much more resistance in the circuit than I thought.
I used a homemade 3AA battery holder and just used a piece of roundstock aluminum to complete the circuit. I rechecked the current with 1ohm resistance and then direct drive.
1ohm------ 217 ma
DD-------- 257 ma
The current was very stable, and would fluctuate within +/-5ma when I wiggled the aluminum roundstock in the battery holder. The brightness increase with this 40ma current increase was very noticeable. /ubbthreads/images/graemlins/grin.gif
It seems as though I'll need to do the mod first, then run my two wires through the body of the E2e and out the rear with the tailcap off. Then I'll be able to see if heat is a problem and try DD or use resistance if needed. /ubbthreads/images/graemlins/icon15.gif
I used a homemade 3AA battery holder and just used a piece of roundstock aluminum to complete the circuit. I rechecked the current with 1ohm resistance and then direct drive.
1ohm------ 217 ma
DD-------- 257 ma
The current was very stable, and would fluctuate within +/-5ma when I wiggled the aluminum roundstock in the battery holder. The brightness increase with this 40ma current increase was very noticeable. /ubbthreads/images/graemlins/grin.gif
It seems as though I'll need to do the mod first, then run my two wires through the body of the E2e and out the rear with the tailcap off. Then I'll be able to see if heat is a problem and try DD or use resistance if needed. /ubbthreads/images/graemlins/icon15.gif
