That Is not true, while they are less efficient with higher currents if properly heatsinked they will keep getting brighter until at least 5 amps. Iirc Match was able to get one to reach 1450 lumens which is actually more than Cree says they can.
Yeah scaru, but lets stay within realistic values for regular flashlights. :P
So are you suggesting that 3 amps is the best drive current even for something with a copper heatsink?
No. But there is something inbetween 3A and 5A. Talking about the usual hosts like P60, C8.. I'd say for limited use, 3.5A is the limit. For short "bursts", it might even be close to 4A.. but heat sag occurs rather fast. Most budget lights dont even have proper heatsinking so assuming a well built light with copper heatsink is a little unrealistic. :P
@Silicon: What I'm now telling you might be VERY wrong but it could also be more true than I expect it to be.. anyway, LEDs have a fordward voltage (Vf). They wont light up below that. Voltage determines the maximum current, so an XML wont pull 4A at 2.8V.. it might pull 6A at 4V but it doesnt have to. Thats where the AMC chips come in handy. They limit the current and also burn up some of the voltage but I dont really know if that matters..
Youâre right, I donât understand you. I donât understand why you keep questioning the answers provided by people who understand the laws of physics. âHmm, I donât quite agree with the answersâ
The key for an LED is I (Current) - Voltage is completely irrelevant. That is why, if you read the CREE datasheets, they will give you luminous intensity at a given current without even talking about voltage. An LED is an imperfect device - every single one of them is different, and this is why Vf in the datasheet is given as a âTypicalâ value and a âMAXâ value, and they are pretty significantly different. A âMINâ isnât even defined in the datasheet, because CREE doesnât consider it a problem (and theyâre right) if the Vf is lower than Typical. The âGoalâ as you put it has NOTHING to do with 3.35V. With an LED, you either control current or you control voltage - the other value becomes what it needs to be all by itself. AMC7135s regulate current.
If itâs not as bright as your TN12, then any of these is possible:
- Your TN12 is driven to higher than 3.4A (meaning there is nothing wrong with your driver)
- Your TN12 has a much higher BIN Emitter than the one youâre working with (U2 compared to T4, for instance) (meaning there is nothing wrong with your driver)
- Your TN12 has much better heat-sinking than whatever is currently heat-sinking your LED (meaning there is nothing wrong with your driver)
- Your driver is broken and not actually supplying 3.4A
- Your power source (battery?) can not provide 3.4A
- Your power source (battery?) does not provide enough voltage for the LED to operate at 3.4A (measure your battery voltage while itâs running the LED)
If you canât measure current, then you can not verify if a current regulator is working. To see if a current regulator is putting out its intended current, youâll have to measure that value.
It depends on the heat-sinking of the LED and the efficiency of the optics. 700 Lumens OTF of an XM-L based flashlight is pretty normal.
Your being a newbie and having a lack of knowledge is no problem - there are lots of us here willing to help. That you continue to ignore the answers provided and replace fact with assumption and ill-knowledge is a bit more frustrating.
PPtk
I have just read some more docs about how do drive a led and I got it now.
Just relax, it is also frustrating for me to get answers like those
Subject is closed :o
âNever Mindâ is the new Original Post? I wouldnât count on getting a lot of help from the people here with that kind of attitude.
E1320, Dr Jones, willie, Vieplis, scaru, NightCrawl, and I all offered you answers, and you still continued to imply that our answers were wrong and that you needed to increase voltage but not current - which is impossible. If youâre uncomfortable being presented with answers that make sense, then Iâm sorry about that.
Good luck with your mod.
PPtk
Dr. Jones (or anyone), could you maybe elaborate? I am getting some intermittent âflickeringâ (funny sounding word lol) with my SE-1 (Balder) and I pulled tail cap & it seems ok. The head is potted so canât get at that. Bad tail cap switch? Chip? Any ideas? I need to find the prob before the send back window closes. Appreciate any help.
Keith (who donât like no flickering)
Most likely either Bad Tail-Cap switch or cell isnât being held tightly enough by spring tensions. Does it flicker if you set it down and let it lie still?
Is it in all modes or just med/low? Might be PWM.. or you should stop shaking the light. :P
My best guess is also what PPTK said.
If removing the tailcap and placing a piece of wire shorting out the tail cap does fix it then try making a small spacer to place in the battery tube. If that fixes it then you need a longer spring.
[quote=PilotPTK]
Most likely either Bad Tail-Cap switch or cell isnât being held tightly enough by spring tensions. Does it flicker if you set it down and let it lie still?
Iâm thinking switch as well. Yes, it flickers when laying still. I have stretched spring already but will try & stretch a little moreâŚâŚâŚ.maybe add a magnetic spacer. Thanks. Iâll post findings.
Keith
Easy enough to diagnose, just short the battery -ve to the body and see if it still flickers. If it doesn't you've got a bad switch.
Is it in all modes or just med/low? Might be PWM⌠or you should stop shaking the light.
My best guess is also what PPTK said.
Not PMW. I just tried it and it is working perfect. But as I stated it is a intermittent issue.
Keith
If removing the tailcap and placing a piece of wire shorting out the tail cap does fix it then try making a small spacer to place in the battery tube. If that fixes it then you need a longer spring.
Not sure I understand what you mean scaru with the wire/shorting. Could you describe? Now it is flickering again. DRATS! This is the lighthound version and I have the Balder version coming (any day now) at which time I shall try the tail cap from it. I also tried a magnetic spacer. Stretched spring, cleaned it good. Before hitting save I checked and it is working (this is how it does). Thanks guys.
Keith
Ok, what I was trying to say is first just use a piece of wire connecting battery to the host so as to rule out the switch. If that does fix it. Ie no flickering then it is the switch to figure out whether it is the spring or some internal part, you place a spacer in there so you can be sure the spring has good contact. If that fixes it you need a longer spring if it doesnât then it is the switch. I hope that helps.
Ok, what I was trying to say is first just use a piece of wire connecting battery to the host so as to rule out the switch. If that does fix it. Ie no flickering then it is the switch to figure out whether it is the spring or some internal part, you place a spacer in there so you can be sure the spring has good contact. If that fixes it you need a longer spring if it doesnât then it is the switch. I hope that helps.
I understand. Tried spacer no worky. Just eliminated switch with paper clip and still no good. So itâs in the head then? If no other ideas then its RMA I guess. At least it is Lighthound Iâm dealing with meaning no hassle quick turn around. I still hate it! Thanks scaru.
Keith
Yep, RMA Time. Iâm very surprised that itâs not the tailâŚ
Yep, RMA Time. Iâm very surprised that itâs not the tailâŚ
The problem is sometimes it will do it all the time & then it âfixesâ itself & will have to be left on for a few minutes or more till it starts flickering. You know how it goesâŚâŚâŚsomething does not work till you take it in then it works. Iâm concerned they will turn it on & off a couple of times & say nothing is wrong. I am going to call LH & explain it in detail for them. It is working fine as I type (I mean peck). The one I have is the LH version with the head up clip. I also have one coming with the head down clip from IO (been 3 wk). If I had purchased this one from China, I would not even send it back. Before I sent this post I went outside with my dog & left the light on &âŚâŚâŚâŚâŚ.you guessed it, working perfect! Oh, the humanity! I love this little light & just hope this is not the down fall of this âbudgetâ light. I am gonna hit send & its still working perfect. BTW, thanks all for trying to help. I just turned it off/on & yepâŚâŚâŚâŚit started flickering LMAO.
Keith
A quick video clip will explain everything, even if the light decided to be OK after returned.