I bought three of the "Q5" CREE emitters on "Premium Star" boards from Kai and three from DX. I don't have a Cutter Q5 for comparison, but the Kai/DX products are noticeably LESS BRIGHT than the original P4 with a similar tint when tested in an Eastward YJ "U2 Style" light supposedly running at 1200 mA. Nothing on the star boards or emitter indicates that these are Q5 emitters, and I have to conclude that they are not. I put the original P4 star board back in the light because it was brighter.
Cree Q5 bins...already? Can anyone be sure?
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I bought three of the "Q5" CREE emitters on "Premium Star" boards from Kai and three from DX. I don't have a Cutter Q5 for comparison, but the Kai/DX products are noticeably LESS BRIGHT than the original P4 with a similar tint when tested in an Eastward YJ "U2 Style" light supposedly running at 1200 mA. Nothing on the star boards or emitter indicates that these are Q5 emitters, and I have to conclude that they are not. I put the original P4 star board back in the light because it was brighter.
You really can't make that conclusion unless you have a way to factor out potential differences in LED Vf. Hook the LEDs up to a current regulated power supply, and then compare.
jake25
Enlightened
i got a Q5 from cutter, put it in my EastwardYJ and the WC is much brighter
Curious_character
Flashlight Enthusiast
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I finally received today some Q5 emitters on stars which I'd ordered from DX on August 9. I just compared one to a P4 bin, both mounted on a large heat sink. The DX Q5 put out 23.3% more light at 100 mA, rising to 28.5% at 1A. The forward voltage of the DX Q5 is just about 0.3 volt higher than the P4 over the 100 mA - 1A current range. Although I didn't measure them, some Q5 emitters I got from a group buy also evidently have a higher Vf, since a Fenix P3D CE runs for a shorter time with a 17670 before flickering since I changed its emitter to a Q5.
c_c
c_c
Yenster
Newly Enlightened
bspofford,
I had the same thing happen to me, but now I know more about the Q5. It requires a higher front voltage to drive it properly so what you're seeing the dimmer light resulting from less current. If you have a multi-meter, you can measure this yourself and see what I'm talking about. The solution, specifically for the Eastward YJ "U2 Style" light, is the get into the driver and short out the resistor at "R1". That will bring up the current from around 400mA to around 700 mA. You will probably to very happy with this mode. However, if not, then go to the next level and direct drive the Q5 by moving "LED -" to "J1". This will result in around 950mA and you're bound to be happy with that brightness. Let us know how it goes.
I'm also seeing that some of these lights don't come as described, i.e. 1200mA. Mine was only pulling around 440mA while others claim theirs pulled 1200mA, maybe some variations with the driver, or maybe some drivers were defective and were actually direct driving. I see a pattern where the 1200mA ones see good results with their Q5 mod, and the 440mA ones didn't. So the above mod is for the 440mA lilghts, probably like yours.
I had the same thing happen to me, but now I know more about the Q5. It requires a higher front voltage to drive it properly so what you're seeing the dimmer light resulting from less current. If you have a multi-meter, you can measure this yourself and see what I'm talking about. The solution, specifically for the Eastward YJ "U2 Style" light, is the get into the driver and short out the resistor at "R1". That will bring up the current from around 400mA to around 700 mA. You will probably to very happy with this mode. However, if not, then go to the next level and direct drive the Q5 by moving "LED -" to "J1". This will result in around 950mA and you're bound to be happy with that brightness. Let us know how it goes.
I'm also seeing that some of these lights don't come as described, i.e. 1200mA. Mine was only pulling around 440mA while others claim theirs pulled 1200mA, maybe some variations with the driver, or maybe some drivers were defective and were actually direct driving. I see a pattern where the 1200mA ones see good results with their Q5 mod, and the 440mA ones didn't. So the above mod is for the 440mA lilghts, probably like yours.
f22shift
Flashlight Enthusiast
is it mounted on a white star or black in dx pictures?
Yenster
Newly Enlightened
My Q5s from DX were on black stars, just like their pictures.
Re: Q5 from DX is visibly dimmer than Q2
A battery will measure 4.1-4.2 V when fully charged, but it spends much more of the discharge cycle at 3.7-3.6 V, or less under load. If I remember correctly, the EastwardYJ U2-style light has a boost circuit. Removing the circuit might make the light brighter on a fresh battery, but dimmer otherwise.
f22shift
Flashlight Enthusiast
kd has them in white in their pics. i received white
Yenster
Newly Enlightened
Who knows which is whichkd has them in white in their pics. i received white
Yenster
Newly Enlightened
Re: Q5 from DX is visibly dimmer than Q2
The problem is that the driver/boost doesn't work well with the Q5s, so even at 3.7-3.6V, the Q5s are brighter without the circuit.
Re: Q5 from DX is visibly dimmer than Q2
Then it's probably even brighter without the Q5.The problem is that the driver/boost doesn't work well with the Q5s, so even at 3.7-3.6V, the Q5s are brighter without the circuit.
Yenster
Newly Enlightened
Cree Q5 bins dimmer that P4...sometimes.
Yeah, some people are finding that their P4 lights were brighter than after a Q5 upgrade. It seems it depends on how the LED is driven and powered so that the higher front voltage needs are met.
Yeah, some people are finding that their P4 lights were brighter than after a Q5 upgrade. It seems it depends on how the LED is driven and powered so that the higher front voltage needs are met.
