I’ve been playing with leds for a few years now, and my favorite lights always have been the zoomies:
But the ones from the shops don’t go that large.
I built some bigger aspheric zoomies earlier; the Huygens Ultimate, a 250mm (XR-E) 2,1 mcd led lamp, and a 75mm (SST90) with 80kcd.
Usually I get inspired by build-logs or because I want to test how ideas can be combined and applied.
(All my previous experiments are on the other forum under same alias. I like postings to be illustrated, and Flickr supports that.)
This time I was aiming for a simple, compact and solid light.
Months ago I decided to go with this concept:
Principle
Moving the lens forward/batteryholder backwards, the led turns on, projecting from flood to focussed.
The O-ring is to give friction, holding the position without accidentally losing the head.
When the light is stored, the O-ring should seal the inners from moist and dust.
I planned to use 8xAA Nimh and XM-L direct drive, but DrJones pointed me at the AMC7135 combined with protected Li-ion. I adopted his suggestion as he is smarter then me.
AMC7135 for size:
Soldering the AMC7135 was difficult. Luckily I found someone to help me out with that.
I have three lenses that fit. Will choose after testing. One is old 76mm Ebay/DX, other is 75mm Thorlabs (preferred so far) and a 75mm Edmunds. The new DX 78mm doesn’t fit without grinding.
Will be using a XM-L T5 on copper star, powered at 3.1Amp by 9x AMC7135 from 7x14500 AW Protected cells.
The electronics and reed-switch will be housed in one out of 8 cell-bays.
On the front of the batteryholder a PCB will close the circuit from all batteries to the driver. On this PCB there will be a small spring with a magnet to activate the reed-switch.
That will need some testing and tuning to have it aligned properly.
Still thinking of potting the electronics or not. I like it to be durable, but do want the AMC’s to be cool.
Led and reed and magnet:
The longest wait so far was in finding a workshop that was affordable. Machining is done, very close to perfect, by using a conventional lathe and a CNC-mill.
As it would act like a piston a part of the aluminium has a longitudinal groove for pressure relief. When the light is ‘off’ , the O-ring seals the innerds.
The light will be anodized black when all testing is done.
Have to make some adjustments to recess some wiring, enlargeing the relief groove and sand/polish the aluminium to fine-tune the pressure from the O-ring.
Assembly in off/storage position
Assembly in on/focused position (45mm BFL)
This light is now about 1/3th finished. Will update posts or add a new post to this thread when I have more to share!
What do you think? Could it work?