KevinL
Flashlight Enthusiast
Building upon Phaserburn's research, which involved using a Pelican Big D SLA 24W bulb in a Maglite to create a superlight, I present the Roar of the Pelican.
Early research by Fh.D Hooked_On_Photons has indicated that the Pelican bulb provides a reasonable approximation of Mag60 performance when driven on 7 AA Energizer/Sanyo 2100mAH NiMH cells ( WA Bulbs - Alternatives for the meantime). The Mag60 is a well known mod using the Welch-Allyn 1160 bulb, delivering 326 lumens at spec and 618 lumens when pushed to a nominal 6V ( WA Group Buy). However, this is far from the most impressive mod in the book and the Pelican Big D delivering sub-Mag60 performance seems underwhelming especially when the Big D's bulb is rated for 600 lumens at its nominal voltage.
I have discovered that AA NiMH, even high quality 2100mAH Sanyo NiMH, do sag significantly under load. My recently constructed Mag3X-1D using AA NiMH cells driving 3xLux3 in parallel delivered a sustained current of 800mA, due to the voltage sag being too close to the Vf of the Luxeons (the benefits being runtime, vs crazy brightness. 3xLux3 underdriven is still twice as bright as 1xLux3 driven at 800mA).
As such, I worked on a solution to bring more powerful cells to the table. My preferred implementation would drive the Big D at a nominal 7.2V, with as little sag as possible due to my choice of ultra-high-current cells. Initially this plan called for 6 Sub-C GP3300 30-amp cells, but due to product availability, was changed to Sanyo 3600mAH high-rate RC cells, which should provide adequate performance as well. The cells were professionally assembled into a straight stick of six, charged on a Maha C777 and left to rest for two days while the bulb got here.
The 4D Mag housing was donated by the OA4D Cookbook Mag, which it started life as, and now has come to realize its true destiny. Sorry, 80 lumens just doesn't cut it, not when you can get 800!! A quick look at the rerating formulas yields (((7.2/6.0)^3.5) * 600) = 1135 bulb lumens. Derating by 30% for optical losses yields approximately 794 effective lumens. This puts the Pelican Big D squarely in Mag85 territory.
Now I was never one for theory, I'm more into operations - what actually happens when you click the switch and let the lumens rip. The six SubCs were too long to accomodate the original Mag spring, so I removed the spring and deanodized the tailcap with the assistance of a sharp screwdriver and 200-grit sandpaper. I also rolled a paper sleeve for the SubCs to fit inside the D-cell light.
Install the bulb as you would any ordinary PR bulb, change the lens and reflector, reassemble, and light it up.
Even when going up against a Mag85 with packs HOT off the charger (2100mAH Sanyo NimH, 9 cells), the rested Pelican holds its voltage so much better that it yields both a brighter and whiter beam, as confirmed by the ceiling bounce test. The higher CCT of the beam is especially appreciated since I love white light and lots of it.
Conclusions? With the right power pack (none of this wimpy AA business) built out of high-current Sub-Cs to match the awesome 4 amp drain of the Pelican lamp, the Big D SLA bulb is all but unstoppable. Bright white beautiful light, brighter and whiter for much longer. It fits in a standard PR base and one of CPF's most popular metal reflectors fits - perfectly.
The downside of the Roar of the Pelican is that it requires a specialized pack charger, putting it out of the reach of flashaholics without the benefit of pack capable chargers, but this will not even slow down the truly hardcore with programmable pack chargers that put mine to shame. Some may object to 4D length, others may enjoy it, it's a matter of personal preference. But me? I'm glad it turned out well.
Special thanks to:
litho123 for making the reflectors happen
Phaserburn and Hooked_On_Photons for blazing the trail
Fivemega for the bulbs - they were getting hard to find (and if you guys want some I think he still has them - $9 for the two-pack)
Silverfox for confirming that the reflectors will fit before I threw down money on the bulbs
Early research by Fh.D Hooked_On_Photons has indicated that the Pelican bulb provides a reasonable approximation of Mag60 performance when driven on 7 AA Energizer/Sanyo 2100mAH NiMH cells ( WA Bulbs - Alternatives for the meantime). The Mag60 is a well known mod using the Welch-Allyn 1160 bulb, delivering 326 lumens at spec and 618 lumens when pushed to a nominal 6V ( WA Group Buy). However, this is far from the most impressive mod in the book and the Pelican Big D delivering sub-Mag60 performance seems underwhelming especially when the Big D's bulb is rated for 600 lumens at its nominal voltage.
I have discovered that AA NiMH, even high quality 2100mAH Sanyo NiMH, do sag significantly under load. My recently constructed Mag3X-1D using AA NiMH cells driving 3xLux3 in parallel delivered a sustained current of 800mA, due to the voltage sag being too close to the Vf of the Luxeons (the benefits being runtime, vs crazy brightness. 3xLux3 underdriven is still twice as bright as 1xLux3 driven at 800mA).
As such, I worked on a solution to bring more powerful cells to the table. My preferred implementation would drive the Big D at a nominal 7.2V, with as little sag as possible due to my choice of ultra-high-current cells. Initially this plan called for 6 Sub-C GP3300 30-amp cells, but due to product availability, was changed to Sanyo 3600mAH high-rate RC cells, which should provide adequate performance as well. The cells were professionally assembled into a straight stick of six, charged on a Maha C777 and left to rest for two days while the bulb got here.
The 4D Mag housing was donated by the OA4D Cookbook Mag, which it started life as, and now has come to realize its true destiny. Sorry, 80 lumens just doesn't cut it, not when you can get 800!! A quick look at the rerating formulas yields (((7.2/6.0)^3.5) * 600) = 1135 bulb lumens. Derating by 30% for optical losses yields approximately 794 effective lumens. This puts the Pelican Big D squarely in Mag85 territory.
Now I was never one for theory, I'm more into operations - what actually happens when you click the switch and let the lumens rip. The six SubCs were too long to accomodate the original Mag spring, so I removed the spring and deanodized the tailcap with the assistance of a sharp screwdriver and 200-grit sandpaper. I also rolled a paper sleeve for the SubCs to fit inside the D-cell light.
Install the bulb as you would any ordinary PR bulb, change the lens and reflector, reassemble, and light it up.
Even when going up against a Mag85 with packs HOT off the charger (2100mAH Sanyo NimH, 9 cells), the rested Pelican holds its voltage so much better that it yields both a brighter and whiter beam, as confirmed by the ceiling bounce test. The higher CCT of the beam is especially appreciated since I love white light and lots of it.
Conclusions? With the right power pack (none of this wimpy AA business) built out of high-current Sub-Cs to match the awesome 4 amp drain of the Pelican lamp, the Big D SLA bulb is all but unstoppable. Bright white beautiful light, brighter and whiter for much longer. It fits in a standard PR base and one of CPF's most popular metal reflectors fits - perfectly.
The downside of the Roar of the Pelican is that it requires a specialized pack charger, putting it out of the reach of flashaholics without the benefit of pack capable chargers, but this will not even slow down the truly hardcore with programmable pack chargers that put mine to shame. Some may object to 4D length, others may enjoy it, it's a matter of personal preference. But me? I'm glad it turned out well.
Special thanks to:
litho123 for making the reflectors happen
Phaserburn and Hooked_On_Photons for blazing the trail
Fivemega for the bulbs - they were getting hard to find (and if you guys want some I think he still has them - $9 for the two-pack)
Silverfox for confirming that the reflectors will fit before I threw down money on the bulbs
