Another portable Lighthouse

From my previous postings here, here and here and the subsequent discussion it has already become quite obvious what the finished light looks like. For completeness I'd like to add a short summary of the main specifications. Here we go:

Body: Maglite 4D
Bulb: Osram 64625 HLX (12V/100W/50h)
Light Output: 3600blm
Battery Pack: 12V/4.6Ah (20×HR-3U AA Cells)
Run Time: 27.5 to 28min

Beam shots (batteries approx. 50% discharged):


Right: Lupine 'Nightmare' bike light (550lm, 20º), Left: Maglite


Bottom: H4 car headlights on low beam, Top: Maglite

The difference in color temperature may be somewhat exaggerated by the camera.

Regards,
Snoopy

Wow!

The stock switch is still in there, right? How did you manage to cram 20 AA cells in there as well? Is your pack 5 cells long?

-Dave

Congratulations, Snoopy!

Some questions:

The battery configuration, is it two parallel stacks of 10 series cells? And how are they held together? A battery holder? A battery pack? And how is the battery holder or pack held in place in the light? And what is the electrical pathway? It goes through the body of the light and through the switch ground set screw, right? And tail cap spring?

And what about the reflector? What kind is it and did you modify it or anything?

And finally, any idea what the voltage of the batteries under load is?

Sorry about the laundry list of questions, but ever since your initial three posts I've been wondering about some of these things, especially how the battery pack or holder is held in place if you're only using the switch core, and where the electronics fit into the configuration and how they avoid getting crushed.

Please understand that I am not at all intending to critique your work. I just want to understand how everything fits together.

BTW, are you going to do a run of your excellent looking GY6.35 lamp/socket holder? As I mentioned before, I'm in for one if you do.

Thanks for posting about this Snoopy, and again, congratulations. Making an Aurora class light is no simple task.

Dave & Jim:

here is a photo that shows the battery holder, electronics and lamp holder:



The rubber bands keep the cells from flipping out of the holder before it goes into the body tube. I'm using two parallel stacks of 10 cells each in a 4x5 holder. The body tube is slightly bored out to a diameter of 35.0mm. This is wide enough to allow for easy installation but still narrow enough to prevent any rattling of the cells. In lengthwise direction the holder is held in place between the switch core (blue cylinder) and tail cap.

Both the (+) and (-) battery contacts are located on the front PCB (facing the lamp holder). So the electrical path does not go through the tail cap spring, body tube and ground screw as in a standard Maglite. The battery contacts are directly connected to the electronics on the front PCB. Using MOSFETs for switching the bulb current allows to maintain the original switch.

The reflector is a modified MR16 glass reflector. I've removed the lamp socket which enables to use a broader variety of single-ended halogen bulbs and provides focusing capability.

I haven't measured battery voltage under load so far but according to the data sheet it should be around 1.15V per cell.

I'm in the process of preparing a small production run of the lamp holder. The estimated cost will be somewhere between $20,- and $25,- + shipping. Please send me a PM if you want one.

Hope I was able to answer your questions. Thanks for your detailed interest in my work.

Regards,
Snoopy

Excellent, Snoopy. Good stuff. Sorry, I forgot about the reflector. DUH! My fault. Good to know that you are direct connecting the electrical pathway.

Portable Lighthouse indeed.

Fantastic.

Also, my compliments on the Q and A session, gentlemen.


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- Jeff