new P7 driver 3amps?
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StefanFS
Flashlight Enthusiast
~10 hours on low is what I got from six fresh eneloops in an mdocod battery holder in a 2D Mag. Not going to bother with medium, it drained the cells to ~0.9 Volt.
nightstalker101
Enlightened
Ya, I'm not sure either, I ran mine for 15min on high and it was too hot to touch.
Which area gets hot (or just the whole thing?) ?
nightstalker101
Enlightened
I'm not really sure which area heats up, however the whole thing ends up getting hot. I'm not sure if thats a bad thing, however its questionable.
SUBjohan
Newly Enlightened
I left mine running on high at 10V for 30mins and the auto-alarm did-not kick in. The driver was in free air.
Greetz Johan
I've received and installed mine now; I potted it to the underbelly of a P7 heatsink. It DOES "auto-alarm" after about 60 seconds of being on high. That is--it switches to the low mode. (I can begin to feel the heat on the outside of the flashlight body.) Then, apparently after cooling off for some seconds, it switches back to high again, and then repeats this later on... It does NOT do any of that after many minutes of medium-level. And if I'm reading your measurements right, the board itself produces the same amount of heat either way (high vs medium), so the difference then is the heat from the LED and through the heatsink, which (I assume) is being detected by the board. Unless I'm off the deep end now, then it seems like potting it to an LED heatsink the way I did doesn't cool the board, but actually heats it up... (?)
Packhorse
Flashlight Enthusiast
What voltage are you running into it?
About 11.7 volts. Do you suppose it's more efficient at higher or lower input voltages?
Edit: ((My guess would be higher voltages))
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SUBjohan
Newly Enlightened
Nope, the higher the voltage the less efficient it gets.
And over 10V the Watt losses go up verry quick :sick2:
I think (not measured :mecry
that the Watt losses around 12V should be 3,5 Watts wich get turned into heat. At 6V the Watt losses are 2,1 Watts (I did measure this
) wich is 40% less heat.Greetz Johan
milkyspit
Flashlight Enthusiast
You're right, that's not a particularly good idea. (I learned the hard way some time back!)
As for heat, just taking a wild guess but one source might be the inductor itself, particularly if the inductor is a little less efficient than it could be. That's a lot of power passing through the inductor and things could easily get pretty toasty. Inductors are a pretty simple component, but the subtleties of forming a good one make their construction kind of a black art. The really good ones are few and far between, and typically cost a heck of a lot more than one would expect given the materials involved. :shrug:
Anyone have an extra piece or two of this board they might be willing to sell? I'll place an order with Kaidomain but would also like to grab a board or two in the near term to play with.
Packhorse
Flashlight Enthusiast
OK I just made up a heat sink for my board. Its basicly a 1 inch x 1inch aluminium channel. I drilled a 9mm hole for the inductor to sit in and thermal pasted it in place.
I ran it for 5 minutes off a 12V battery (battery is a little flat and was at 12v) and ran 2 P7s in series off it.
High 1.9amps 22.8watt output 2.6 amps at 6.7v 17.42 watt or 76% efficient (it did drive a single P9 to 2.8amp)
Med .60 amps 7.2watt Output .77amps 3.12v 2.4watt 33% efficient.
Low .21 amps 2.52watt Output.24amps @1.8v .432watt 17% efficient.
Med and Low seem way way inefficent. perhaps I misread. I will remeasure again later.
But the important thing is that I can run 2 P7s off of it at 12v & it did not go into heat protection mode. It got warm but not hot. :twothumbs
I ran it for 5 minutes off a 12V battery (battery is a little flat and was at 12v) and ran 2 P7s in series off it.
High 1.9amps 22.8watt output 2.6 amps at 6.7v 17.42 watt or 76% efficient (it did drive a single P9 to 2.8amp)
Med .60 amps 7.2watt Output .77amps 3.12v 2.4watt 33% efficient.
Low .21 amps 2.52watt Output.24amps @1.8v .432watt 17% efficient.
Med and Low seem way way inefficent. perhaps I misread. I will remeasure again later.
But the important thing is that I can run 2 P7s off of it at 12v & it did not go into heat protection mode. It got warm but not hot. :twothumbs
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DocD
Enlightened
So the way i'm understanding this is that the driver, has hope for being able to drive 2 P7's or may more? but as a single driver,ok on high and rubbish on med and low.
Phaserburn
Flashlight Enthusiast
I know it's not as elegant a solution, but why not direct drive the P7 with three nimh D cells? No circuit losses or circuit heat issues to deal with. The nimh cells will hold voltage easily and provide around 2.8 - 3A to the emitter (with a vf of 3.25 - 3.5V), while giving excellent runtime to boot. I would think that dimming due to voltage drop in this scenario would be hard to detect by eye over the course of a long burn.
Packhorse
Flashlight Enthusiast
For me, I would rather have full brightness for the whole of the run time. Plus the low volt warning.
The 2 lower power levels and thermal protection are just bonuses.
Not to mention the ability to run it off an existing 12volt battery pack.
The 2 lower power levels and thermal protection are just bonuses.
Not to mention the ability to run it off an existing 12volt battery pack.
Re; What gets hot and how to manage it.
Been following this but just too busy to contribute. Last night I wired up my board and used my calibrated finger to see what got hottest first (an ancient and sensitive measurement often used back in the days of "valves").
Result:
Since this side of the board has components of different heights and this is one of the low profile ones it makes sense to build it up to the top level and heat sink to it. A small piece of 3mm Al plus heatsink epoxy works well:
I then epoxied the "new flat profile" onto a dicast box I'm using for a project I'll publish in the next week or 2 and ran it for 15mins on hi with 8V in. There were no problems and I could still touch the other side of the driver at 15 mins.
Been following this but just too busy to contribute. Last night I wired up my board and used my calibrated finger to see what got hottest first (an ancient and sensitive measurement often used back in the days of "valves"
).Result:
Since this side of the board has components of different heights and this is one of the low profile ones it makes sense to build it up to the top level and heat sink to it. A small piece of 3mm Al plus heatsink epoxy works well:
I then epoxied the "new flat profile" onto a dicast box I'm using for a project I'll publish in the next week or 2 and ran it for 15mins on hi with 8V in. There were no problems and I could still touch the other side of the driver at 15 mins.
Aircraft800
Flashlight Enthusiast
I have the newer version of this driver, there is two components where you have the spacer, is the heatsinking the same? Has anyone had any experience with the newer driver?
Is this where I would need to heatsink?
Is this the correct wiring? I can use either negative batt in?
Is this where I would need to heatsink?
Is this the correct wiring? I can use either negative batt in?
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DocD
Enlightened
do ypu have a link? cheers DocDI have the newer version of this driver, there is two components where you have the spacer, is the heatsinking the same? Has anyone had any experience with the newer driver?
Is this where I would need to heatsink?
Is this the correct wiring? I can use either negative batt in?
Aircraft800
Flashlight Enthusiast
http://www.kaidomain.com/ProductDetails.aspx?ProductId=1866
Quote Kaidomain: "Measures 19mm in diameter, and 8mm in height (Note: the diameter changes to 17mm since Aug.28th (shipping day)."
I got the 17mm board, new design.
