There were several mods done, using the X3T LED, being run with 9 volts. Please place your comments here as to how the lower fV of this LED is handling the greater than spec 9 volts being delivered to it. Does the body of the flashlight heat up considerably? How long does it last? Anything you'd care to divulge for this thread. Thank you! /ubbthreads/images/graemlins/smile.gif
Those with X3T. How are they holding up under 9V?
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PeterW
Enlightened
My McLux-PR with DB750 seems to be running just fine. The head gets noticably warm if you run it for a few minutes. Keep yourself warm when it gets all chilly outside.
I haven't given it too much abuse though as it is so nice and shiny.
PEterW
I haven't given it too much abuse though as it is so nice and shiny.
PEterW
I am still learning......does a lower letter mean lower VF? And if so....does it mean it will be bright with less power going through it? And a higher letter means you need more power to make it bright? I have an X3V being power by 9 volts and it never gets warm.
IsaacHayes
Flashlight Enthusiast
if your're worried and aren't using a buck circuit or MR, then use .5 ohm resisor with it it.
LEDmodMan
Flashaholic*
Most of the X3T 5w LS's I know of are being run through some kind of electronics (either MR or DB). That means that the LED only sees the voltage that it is binned to see (mine is 6.7v), only more current is delivered.
It is possible that Mr. Bulk has run an X3T bin DD, but I'm not sure...
It is possible that Mr. Bulk has run an X3T bin DD, but I'm not sure...
Thank you, G Pilot! /ubbthreads/images/graemlins/smile.gif
So, LEDmodMan, are these being run at around the 6.7 volts to preserve the LED?
Reason why I'm asking, I acquired an X3T from someone who had one left, and I got lucky! I've decided to run it off of 5 AA batteries, but the few times I put the extra AA in there to make 6 AA (9 volts), it made a definite difference in the output. However, I don't believe it is in the best interest of the LED to run it with 6 AA batteries, so it will continue it's 5 AA setup.
You say that most are running on electronics, only seeing voltage it is supposed to, but then you say, "...only more current is delivered". What did you mean by that?
So, LEDmodMan, are these being run at around the 6.7 volts to preserve the LED?
Reason why I'm asking, I acquired an X3T from someone who had one left, and I got lucky! I've decided to run it off of 5 AA batteries, but the few times I put the extra AA in there to make 6 AA (9 volts), it made a definite difference in the output. However, I don't believe it is in the best interest of the LED to run it with 6 AA batteries, so it will continue it's 5 AA setup.
You say that most are running on electronics, only seeing voltage it is supposed to, but then you say, "...only more current is delivered". What did you mean by that?
Sorry to hijack your post here, but I still not to sure about the VF ratings. My post from above:
"Does a lower letter mean lower VF? And if so....does it mean it will be bright with less power going through it?
And a higher letter means you need more power to make it bright?"
I ask this because I bought a Q4H. It has a low VF. Will it blow easier than one with a high VF?
Thanks
"Does a lower letter mean lower VF? And if so....does it mean it will be bright with less power going through it?
And a higher letter means you need more power to make it bright?"
I ask this because I bought a Q4H. It has a low VF. Will it blow easier than one with a high VF?
Thanks
LEDmodMan
Flashaholic*
What I mean is that they are current regulated circuits (both MR and DB). The LS only sees the voltage that it is happy with (based on the bin) the way the circuit is set-up (it "detects" the Vf of the LED), but they are overdriving the LED WRT current (the MR is adjustable from 0 - 3 Amps, mine runs at 1.5A).
With DD, you're overdriving both current AND voltage. An LS diode can handle being current overdriven much better than voltage overdriven. In any LS overdrive case, <font color="red">really good heatsinking is a huge must!</font>
However, keep in mind that all Space Needles and Space Needle II's are all running at 9v (3x123) and I haven't heard of any failures. Mr. Bulk is the expert here.
I ran two different LS's on two banks of 6 Alkaline AA's in series, and fried both of them (an unknown bin SE and a W3W bin HD). I imagine that the two parallel banks of batteries didn't allow enough voltage drop, and the LEDs pooped out from overvoltage. This didn't happen until about three sets of batteries had gone through each though.
All I can say is that it isn't as bad losing a cheap 5w LS to an overvoltage failure, but I would protect that X3T you've got. The W3W I lost was painful enough, I sure wouldn't want to lose my X3T for $50 down the /ubbthreads/images/graemlins/smoker5.gif
With DD, you're overdriving both current AND voltage. An LS diode can handle being current overdriven much better than voltage overdriven. In any LS overdrive case, <font color="red">really good heatsinking is a huge must!</font>
However, keep in mind that all Space Needles and Space Needle II's are all running at 9v (3x123) and I haven't heard of any failures. Mr. Bulk is the expert here.
I ran two different LS's on two banks of 6 Alkaline AA's in series, and fried both of them (an unknown bin SE and a W3W bin HD). I imagine that the two parallel banks of batteries didn't allow enough voltage drop, and the LEDs pooped out from overvoltage. This didn't happen until about three sets of batteries had gone through each though.
All I can say is that it isn't as bad losing a cheap 5w LS to an overvoltage failure, but I would protect that X3T you've got. The W3W I lost was painful enough, I sure wouldn't want to lose my X3T for $50 down the /ubbthreads/images/graemlins/smoker5.gif
LEDmodMan
Flashaholic*
G pilot:
Yes, a lower Vf rating will blow easier than a higher one when run direct drive.
However, when used with a current regulated circuit, a lower Vf rating is better since it affords better efficiency in the converter, which makes it a bit brighter.
Yes, a lower Vf rating will blow easier than a higher one when run direct drive.
However, when used with a current regulated circuit, a lower Vf rating is better since it affords better efficiency in the converter, which makes it a bit brighter.
LEDmodMan
Flashaholic*
No problem! My pleasure!
I have no electronics, nor would I have the expertise to do so, therefore, I'd best use only 5 AA batteries for this then. Still, the whiteness and brightness of it under the 7.5 volts is better than than the 9 volts of the W2W. Of course, now I wonder if I'm pushing the W2W too much. I had it on for quite a while one night and the body never even got warm. The color is on the more greenish range, but if there are no white or slight blue LEDs on at the same time, it looks close to white.
Anyway, so I'd best keep the X3T using 5 cells then, is that my best setup, given my lack of electronics skills?
Anyway, so I'd best keep the X3T using 5 cells then, is that my best setup, given my lack of electronics skills?
It never got warm? You're probably doing something wrong then. In most designs, the heat is vented to the flashlight body, but unless you're running yours for fractions of a second, it should get somewhat warm, fairly quickly...
What sort of heasinking do you have set up? If the body of the light isn't getting at all warm, you're not getting the heat from the luxeon to the body, which means it's probably killing the luxeon, unless it's in some really large mag or something...
What sort of heasinking do you have set up? If the body of the light isn't getting at all warm, you're not getting the heat from the luxeon to the body, which means it's probably killing the luxeon, unless it's in some really large mag or something...
It is on one of Elektrolumen's heatsinks, so it is in contact with the body. The LED is attached with Artic Alumina. I remember physically touching the heatsink (took the head off), and it wasn't hot. Hmmm, perhaps I should re-look at this. Pehaps it wasn't warm because it was a cool evening. Could have played a role. /ubbthreads/images/graemlins/icon3.gif
PeterW
Enlightened
Correct me if I am wrong, but I understood that CR123 lithiums (as used in the 9V DD units) have some 'magic' current regulating ability when run in a DD configuration. This is the reason that Charlie can get away with 9V on 5W v2T and the like and not Kill them.
Please correct me if anyone knows better
Cheers
PEterW
Please correct me if anyone knows better
Cheers
PEterW
[ QUOTE ]
PeterW said:
Correct me if I am wrong, but I understood that CR123 lithiums (as used in the 9V DD units) have some 'magic' current regulating ability when run in a DD configuration. This is the reason that Charlie can get away with 9V on 5W v2T and the like and not Kill them.
Please correct me if anyone knows better
Cheers
PEterW
[/ QUOTE ]
The "magic" current regulation in batteries is what's known as internal resistance. It is a byproduct of the limits of how much power can be delivered by the chemical reactions occuring inside a cell.
Abstracting it to the electronics world, a battery can be modeled as a voltage source in series with some resistance value. This resistance value acts to limit the current that a battery can supply.
All batteries (alkaline, NiMH, Li, etc) have some internal resistance. The internal resistance of a cell depends on the cell chemistry, internal construction, charge level, etc.
Alkaline and non-rechargable Lithiums tend to have higher internal resistance than NiMH, which has slightly higher internal resistance than NiCD.
As you increase the amount of current being drawn from a battery, the voltage across the battery terminals will decrease. In direct drive scenarios, the sum of the terminal voltages of all of your batteries will drop to match the Vf of the LED at whatever current is being passed through the LED. The Vf of an LED varies with the current going through it.
3 CR123As do not have a terminal voltage of 9V when they are driving 1A of current through a 5W LS. Their terminal voltage drops because of the amount of current flowing through them.
The internal resistance of non-rechargable cells allows you to (somewhat) safely direct-drive a 5W LS from 3x123As, or from 6AAs (9V Nominal). HOWEVER, if you were to direct-drive a 5W LS from 7xNiMH AAs (8.4V nominal), I can almost GUARANTEE that you will fry that LS. Why? The NiMH cells have far less internal resistance than the Li or Alkalines. Even though they have a lower terminal voltage, they will maintain a higher terminal voltage under high loads, and will be able to deliver MUCH more current than an alkaline or lithium cell can.
If you were to wire up a 9V power supply capable of delivering 50A of current to an LS, you would probably instantly destroy it. The power supply essentially has zero internal resistance, thus, the output voltage will not drop under load, and thus, the Vf of the LED must match 9V. The amount of current flowing through a 5W LS in order for the Vf to reach 9V is a LOT! (probably 4-5A, just guessing).
PeterW said:
Correct me if I am wrong, but I understood that CR123 lithiums (as used in the 9V DD units) have some 'magic' current regulating ability when run in a DD configuration. This is the reason that Charlie can get away with 9V on 5W v2T and the like and not Kill them.
Please correct me if anyone knows better
Cheers
PEterW
[/ QUOTE ]
The "magic" current regulation in batteries is what's known as internal resistance. It is a byproduct of the limits of how much power can be delivered by the chemical reactions occuring inside a cell.
Abstracting it to the electronics world, a battery can be modeled as a voltage source in series with some resistance value. This resistance value acts to limit the current that a battery can supply.
All batteries (alkaline, NiMH, Li, etc) have some internal resistance. The internal resistance of a cell depends on the cell chemistry, internal construction, charge level, etc.
Alkaline and non-rechargable Lithiums tend to have higher internal resistance than NiMH, which has slightly higher internal resistance than NiCD.
As you increase the amount of current being drawn from a battery, the voltage across the battery terminals will decrease. In direct drive scenarios, the sum of the terminal voltages of all of your batteries will drop to match the Vf of the LED at whatever current is being passed through the LED. The Vf of an LED varies with the current going through it.
3 CR123As do not have a terminal voltage of 9V when they are driving 1A of current through a 5W LS. Their terminal voltage drops because of the amount of current flowing through them.
The internal resistance of non-rechargable cells allows you to (somewhat) safely direct-drive a 5W LS from 3x123As, or from 6AAs (9V Nominal). HOWEVER, if you were to direct-drive a 5W LS from 7xNiMH AAs (8.4V nominal), I can almost GUARANTEE that you will fry that LS. Why? The NiMH cells have far less internal resistance than the Li or Alkalines. Even though they have a lower terminal voltage, they will maintain a higher terminal voltage under high loads, and will be able to deliver MUCH more current than an alkaline or lithium cell can.
If you were to wire up a 9V power supply capable of delivering 50A of current to an LS, you would probably instantly destroy it. The power supply essentially has zero internal resistance, thus, the output voltage will not drop under load, and thus, the Vf of the LED must match 9V. The amount of current flowing through a 5W LS in order for the Vf to reach 9V is a LOT! (probably 4-5A, just guessing).
