This post was returned to the thread on 2/8/06.
I just did a little refurbishing of the Aurora prototype. Many of you will recognize the Aurora 3D Mag as one of the inspirations behind Bill Waites' original "Mule" and the ongoing USL project. After a year of mostly sitting around not seeing much action, I fired her up and found that the output was not quite what at the level I remembered. It turns out that several of the KAN1800 4/5A cells had sprung leaks. This was the second Aurora pack containing KAN cells that self-destructed.
So, I built a new power pack out of 11 x GP2000 4/5A cells. GP cells are regarded as some of the best out there for high current applications. Fortunately or unfortunately, depending on how you see it, the output voltage of the GP cells was much stronger than that of the the KANs even when they were new and the Aurora's primary light engine, the 50-hour life Osram 62138HLX was not able to handle it. Three bulbs later, I confirmed that this was absolutely the case.
The unfortunate aspect is that the 62138 has a very compact axial filament and thus throws a nice spot for such a large bulb. The fortunate aspect is that the higher voltage means more overdrive. So, never being one to resist more overdrive I soldered on another cell making it a 12-cell GP2000 pack.
Initial cycling at 3A showed the GP cells to perform pretty much as expected if a bit short in capacity. Voltage stability was good. Since these cells were "zapped" I was anxious to see how they would hold up under extreme loads. According to the GP literature, the GP2000 should deliver a MPV (mid-point voltage) of 1.17-1.18V. This is in agreement with the value of 1.17V I measured at 4.25C. This is significantly better than the 1.09V MPV of the KAN1800 cells. I was, however, disappointed that the GP2000 did not deliver more duration than the KAN1800. Output ran strong until pooping out right around the 10-minute mark. The pack got quite warm.
But what to use for a light engine? Well, the only other decent 12V/100W in this output range (2,800 lumens at spec) was the 2000-hr life Osram 64623HLX. Though the filament is much larger and transverse instead of axial, it was the bulb with which I did the original Aurora development and I still had a few around. Calculations showed that at 14V, this bulb would still have over 300 hours of life. Even better, it would make an estimated 4,800 lumens. Very nice indeed.
And so in it went. Well, if one were to ask if it's possible to tell the difference between 3,000-ish lumens and 5,000-ish lumens, the answer is an emphatic yes. Compared to my modified Vector 2MCP spot which now sports a 62138 bulb, the output is a staggering step up in visual impact and color temperature. And with the 3" turbo head, the spot is not bad at all.
Here's a graph I generated using some data from the original Aurora and the new Aurora V2. You can see that adding an additional cell results in more than one cell's worth of voltage bump. Credit this to the mighty GP2000. The calculated lumens (at the bulb) are arrived at using the generally accepted formula of (Lumens at the spec voltage)*(Vactual/Vspec)^3.5.
So what might this mean to those waiting on the USL? Since the CBP1650 hold voltage even better than the KAN1800 and the USL pack is an 11-cell unit, I'd interpolate the voltage and lumen curves to be between those of the Aurora V1 and Aurora V2. Probably closer to the V1 curves. Probably just above the 3,000 lumen mark at the midpoint of discharge. Another important thing to keep in mind is that these curves are for continuous runs to an ending cell voltage of 0.9V. If you use the light in intermittent squirts with some rest time in between, you'll get a lot more total runtime and your squirts will all be closer to the high end. That's 4,000-ish for the USL and 6,000-ish for the Aurora2.
I apologize if someone on the USL list has already presented output data on that unit. Of course it would be more accurate...but I just haven't kept up with all the USL threads.
What do you think?
Wilkey
I just did a little refurbishing of the Aurora prototype. Many of you will recognize the Aurora 3D Mag as one of the inspirations behind Bill Waites' original "Mule" and the ongoing USL project. After a year of mostly sitting around not seeing much action, I fired her up and found that the output was not quite what at the level I remembered. It turns out that several of the KAN1800 4/5A cells had sprung leaks. This was the second Aurora pack containing KAN cells that self-destructed.
So, I built a new power pack out of 11 x GP2000 4/5A cells. GP cells are regarded as some of the best out there for high current applications. Fortunately or unfortunately, depending on how you see it, the output voltage of the GP cells was much stronger than that of the the KANs even when they were new and the Aurora's primary light engine, the 50-hour life Osram 62138HLX was not able to handle it. Three bulbs later, I confirmed that this was absolutely the case.
The unfortunate aspect is that the 62138 has a very compact axial filament and thus throws a nice spot for such a large bulb. The fortunate aspect is that the higher voltage means more overdrive. So, never being one to resist more overdrive I soldered on another cell making it a 12-cell GP2000 pack.
Initial cycling at 3A showed the GP cells to perform pretty much as expected if a bit short in capacity. Voltage stability was good. Since these cells were "zapped" I was anxious to see how they would hold up under extreme loads. According to the GP literature, the GP2000 should deliver a MPV (mid-point voltage) of 1.17-1.18V. This is in agreement with the value of 1.17V I measured at 4.25C. This is significantly better than the 1.09V MPV of the KAN1800 cells. I was, however, disappointed that the GP2000 did not deliver more duration than the KAN1800. Output ran strong until pooping out right around the 10-minute mark. The pack got quite warm.
But what to use for a light engine? Well, the only other decent 12V/100W in this output range (2,800 lumens at spec) was the 2000-hr life Osram 64623HLX. Though the filament is much larger and transverse instead of axial, it was the bulb with which I did the original Aurora development and I still had a few around. Calculations showed that at 14V, this bulb would still have over 300 hours of life. Even better, it would make an estimated 4,800 lumens. Very nice indeed.
And so in it went. Well, if one were to ask if it's possible to tell the difference between 3,000-ish lumens and 5,000-ish lumens, the answer is an emphatic yes. Compared to my modified Vector 2MCP spot which now sports a 62138 bulb, the output is a staggering step up in visual impact and color temperature. And with the 3" turbo head, the spot is not bad at all.
Here's a graph I generated using some data from the original Aurora and the new Aurora V2. You can see that adding an additional cell results in more than one cell's worth of voltage bump. Credit this to the mighty GP2000. The calculated lumens (at the bulb) are arrived at using the generally accepted formula of (Lumens at the spec voltage)*(Vactual/Vspec)^3.5.
So what might this mean to those waiting on the USL? Since the CBP1650 hold voltage even better than the KAN1800 and the USL pack is an 11-cell unit, I'd interpolate the voltage and lumen curves to be between those of the Aurora V1 and Aurora V2. Probably closer to the V1 curves. Probably just above the 3,000 lumen mark at the midpoint of discharge. Another important thing to keep in mind is that these curves are for continuous runs to an ending cell voltage of 0.9V. If you use the light in intermittent squirts with some rest time in between, you'll get a lot more total runtime and your squirts will all be closer to the high end. That's 4,000-ish for the USL and 6,000-ish for the Aurora2.
I apologize if someone on the USL list has already presented output data on that unit. Of course it would be more accurate...but I just haven't kept up with all the USL threads.
What do you think?
Wilkey
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