*****************************Completed*****************************
Final Setup
4x AA Eneloop in series
1.47 Ohm Resistor
1.09 A (peak for 30 seconds or so - stabilizes at 1.02A)
3.46 Vf
one hour run down to just under 1A (fairly flat) - haven't tested beyond that.
Seoul P4 U-bin
Constructed out of 1" Aluminum tubing, 1/4" channel and 1"x1/8" flat
Runs warm to the touch without airflow.
if you only used this while riding you wouldn't need the fins I don't think
You can see the 1.0 Ohm resistor tucked in between the fins on the between the housing and the lamp assembly. JB Welded just above it is the 0.47 Ohm resistror (in series).
Surefire C3 w/ Lighthound Drop-In running on three fresh RCR 123A (12.6V) - Cree R2 emitter - The beam has a very tight hotspot, which makes for good long throw, but when riding at night, it's a little too intense of a spot, causing the spill to be less useful. This is my current favorite carry light setup. (not to mention the guilt-free lumens with the rechargeables). It's not the best constructed drop-in I've seen, but it works, and works well at that.
My new light running around 1 amp - It looks like I I'm getting similar total output to the previous one (specs show the U binned Seoul P4 used here to have slightly less power that the Cree above at these amp draws), but this beam has much less throw due to the wider hotspot. I haven't ridden with it yet, but I have played with it at night, and the lack of a bright hotspot allows the spill to light up peripheral vision much better. I'm thinking a good setup would be a two floody light like this on the bars, and a hot throwy light strapped to my helmet.
*****************************Update 1*****************************
Here is the first iteration
After testing this, the heat sinking is woefully inadequate. While underway there will be some airflow, but I want the heat sinking to be able to handle use as a room lighter in a pinch. I am in the process of adding fins (1/4" channel) and have cut off the front plastic to allow more air circulation.
Run time is great, and output is acceptable, but I think I can squeeze a little more out of this this, if I can add enough heatsink. After a little nudging from Linger, and the results from me early testing I am going for 4X AA @ 1.47 Ohm (1.1A) if I can cool it, otherwise I will go 2.0 Ohm (0.89 A)
This is really a fun process.
Phase 1 testing results
76 F ambient
3 AAA Eneloops in series
0.47 Ohm, 5W wire wound resistor
0:00 elapsed
4.06 V resting
3.81 V under load
3.25 Vf
0.82 A
5:00 elapsed
3.94 V resting
0.76 A
Housing became hot to the touch - cut power - let cool - this configuration is too powerful for current heat sink - on a positive note, the backing plate and housing ran approximately the same temperature, which means that my JB weld construction is transferring heat.
____
Phase 2 test
(after housing cooled) Housing placed on copper table, and sandwiched between AL tubes to allow the battery-life test to continue. (timer was stopped during cooling)
10:00 elapsed
3.24 Vf
12:18 elapsed
0.73 A
3.67 V battery under load
3.23 Vf
17:00 elapsed
0.73A
3.21 Vf
3.67 V battery under load
40:00 elapsed
0.64 A
3.23 Vf
55:00 elapsed
0.59 A (If resistor is bridged, the batteries will output 0.91 A at this point)
3.20 Vf
3.54 V battery under load
1:12:00 elapsed
0.19 A (bridged resistor will produce 0.40A)
2.79 Vf
2.85 V battery under load
3.54 V battery resting
Phase 3 Test
4x AA Eneloops in series
5.63 V resting
@ 3.47 Ohm - 0.61 A; 3.2 Vf; 5.38 V under load
@ 3.00 Ohm - 0.66 A
@ 2.47 Ohm - 0.77 A
@ 2.00 Ohm - 0.89 A
@ 1.47 Ohm - 1.09 A; 3.46 Vf (we have a winnah!)
*****************************Original Post*****************************
This is a work in progress.
I have really started to ask questions and learn about the intricacies of lamp design here on CPF for a few weeks now, so please excuse any ignorance on my part if I say something stupid.
I will keep this thread updated as I progress through the design and testing phases.
Here is what I have so far:
3 x NiMH AA in series (4.2V 1,900 mAh)
Seoul P4 U bin with a 20mm IMS smooth reflector
Direct drive - Got a reading of 1.51 amps @ 4.11 resting pack voltage (want to add a resistor to get this down to a nominal 1.0 amp drive)
My Questions for Y'all:
What range of resistor values should I get as a starting point for testing?
Would this design be better if I ran four NiMH AA in a 2S2P configuration at 2.75 V, or would I end up with less light output?
[/B]
My old Cat Eye Halogen Bike light ended up being the host
(In its original state with 4x AA alkaline it put out 40 lumens with a 45 min runtime, which I thought was amazing seven years ago) Now I'm running 3X NiMh in series.
Final Setup
4x AA Eneloop in series
1.47 Ohm Resistor
1.09 A (peak for 30 seconds or so - stabilizes at 1.02A)
3.46 Vf
one hour run down to just under 1A (fairly flat) - haven't tested beyond that.
Seoul P4 U-bin
Constructed out of 1" Aluminum tubing, 1/4" channel and 1"x1/8" flat
Runs warm to the touch without airflow.
if you only used this while riding you wouldn't need the fins I don't think
You can see the 1.0 Ohm resistor tucked in between the fins on the between the housing and the lamp assembly. JB Welded just above it is the 0.47 Ohm resistror (in series).
Surefire C3 w/ Lighthound Drop-In running on three fresh RCR 123A (12.6V) - Cree R2 emitter - The beam has a very tight hotspot, which makes for good long throw, but when riding at night, it's a little too intense of a spot, causing the spill to be less useful. This is my current favorite carry light setup. (not to mention the guilt-free lumens with the rechargeables). It's not the best constructed drop-in I've seen, but it works, and works well at that.
My new light running around 1 amp - It looks like I I'm getting similar total output to the previous one (specs show the U binned Seoul P4 used here to have slightly less power that the Cree above at these amp draws), but this beam has much less throw due to the wider hotspot. I haven't ridden with it yet, but I have played with it at night, and the lack of a bright hotspot allows the spill to light up peripheral vision much better. I'm thinking a good setup would be a two floody light like this on the bars, and a hot throwy light strapped to my helmet.
*****************************Update 1*****************************
Here is the first iteration
After testing this, the heat sinking is woefully inadequate. While underway there will be some airflow, but I want the heat sinking to be able to handle use as a room lighter in a pinch. I am in the process of adding fins (1/4" channel) and have cut off the front plastic to allow more air circulation.
Run time is great, and output is acceptable, but I think I can squeeze a little more out of this this, if I can add enough heatsink. After a little nudging from Linger, and the results from me early testing I am going for 4X AA @ 1.47 Ohm (1.1A) if I can cool it, otherwise I will go 2.0 Ohm (0.89 A)
This is really a fun process.
Phase 1 testing results
76 F ambient
3 AAA Eneloops in series
0.47 Ohm, 5W wire wound resistor
0:00 elapsed
4.06 V resting
3.81 V under load
3.25 Vf
0.82 A
5:00 elapsed
3.94 V resting
0.76 A
Housing became hot to the touch - cut power - let cool - this configuration is too powerful for current heat sink - on a positive note, the backing plate and housing ran approximately the same temperature, which means that my JB weld construction is transferring heat.
____
Phase 2 test
(after housing cooled) Housing placed on copper table, and sandwiched between AL tubes to allow the battery-life test to continue. (timer was stopped during cooling)
10:00 elapsed
3.24 Vf
12:18 elapsed
0.73 A
3.67 V battery under load
3.23 Vf
17:00 elapsed
0.73A
3.21 Vf
3.67 V battery under load
40:00 elapsed
0.64 A
3.23 Vf
55:00 elapsed
0.59 A (If resistor is bridged, the batteries will output 0.91 A at this point)
3.20 Vf
3.54 V battery under load
1:12:00 elapsed
0.19 A (bridged resistor will produce 0.40A)
2.79 Vf
2.85 V battery under load
3.54 V battery resting
Phase 3 Test
4x AA Eneloops in series
5.63 V resting
@ 3.47 Ohm - 0.61 A; 3.2 Vf; 5.38 V under load
@ 3.00 Ohm - 0.66 A
@ 2.47 Ohm - 0.77 A
@ 2.00 Ohm - 0.89 A
@ 1.47 Ohm - 1.09 A; 3.46 Vf (we have a winnah!)
*****************************Original Post*****************************
This is a work in progress.
I have really started to ask questions and learn about the intricacies of lamp design here on CPF for a few weeks now, so please excuse any ignorance on my part if I say something stupid.
I will keep this thread updated as I progress through the design and testing phases.
Here is what I have so far:
3 x NiMH AA in series (4.2V 1,900 mAh)
Seoul P4 U bin with a 20mm IMS smooth reflector
Direct drive - Got a reading of 1.51 amps @ 4.11 resting pack voltage (want to add a resistor to get this down to a nominal 1.0 amp drive)
My Questions for Y'all:
What range of resistor values should I get as a starting point for testing?
Would this design be better if I ran four NiMH AA in a 2S2P configuration at 2.75 V, or would I end up with less light output?
[/B]
My old Cat Eye Halogen Bike light ended up being the host
(In its original state with 4x AA alkaline it put out 40 lumens with a 45 min runtime, which I thought was amazing seven years ago) Now I'm running 3X NiMh in series.
Last edited:
