A2 has two selectable LED brightness levels

A2's two-level LEDS

I discovered this feature by accident during testing. After the A2's batteries are depleted so that only the LEDS work, you will be able to select two distinct LED brightness levels. The method of selection mimics the original two-stage function of the light. In this case a light push on the tail button activates a low LED level and a harder push activates a modest but distinct increase in brightness. You may also choose to leave the tail partially screwed in for constant level 1 activation or fully engaged for constant level 2.

Unique bulb

Has anyone noticed that the A2's bulb is unique? It appears to be the only non turbo SureFire bulb with a translucent tip. Also, the filament is located closer to the base than in other SF bulbs, turbo and non turbo. Perhaps most interesting; when compared to (for example) an N2 the A2's glass envelope appears identical in length, diameter, shape and even the configuration of the translucent tip. The A2's filament is thinner and closer to its base than the N2's, but that seems to be the only internal difference. After close examination it becomes clear that this is in fact a turbohead bulb, though plastic-shanked and springless, used in a non turbohead light.

One might have expected that the long bulb with its tip practically kissing the lens would cause inordinate lens heating. In fact it does not. In A2/E2E(MN03) comparison testing during steady "on" periods exceeding 45 minutes, both lights became too hot to comfortably hold, but the A2's lens was barely hotter than the E2E's. The pyrex lenses of both lights preclude cracking, but it would be interesting to know how the considerable heat buildup affects the life of both bulbs, as well as the A2's LEDs.

Say what you want about Surefire; I believe that their creative imagination and the constant evolution of their products is admirable.

Brightnorm

Wow... nicely done Brightnorm - it makes a heck of a lot of sense for two levels of LED brightness when there isn't enough juice to power the incandescent lamp - and a nice feature if you ask me. I haven't found that in any of the literature that I've read so far, so that makes it a very important observation in my opinion. That's definitely good to know.

/ubbthreads/images/graemlins/bowdown.gif Brightnorm

-Jim

Jim, the difference between the levels is modest, but it's very distinct. Hopefully the lower level will provide a significantly longer burn.

BN

I also noticed this. I think the first step is resistored down a bit, while a full depress is non-resistored. So when the batteries get that weak it is more noticeable. I am not sure how much less power it is using though since it is running through the resistor.

If you take the main lamp out you can see what it is doing, my prototype lamp blew after about 2 min so I got to play with the light that way for a while.

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Brock said:
.....If you take the main lamp out you can see what it is doing, my prototype lamp blew after about 2 min so I got to play with the light that way for a while.

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That's how I happened to notice it, except I had removed the bulb.

I hope, probably unrealistically, that SF eventually makes an incandescent-only version of the A2 that's closer to E2E size. I'm not sure how you carry yours, Brock, but I find the A2 just a little too big for comfortable back pocket carry. I have my E2e attached to my mini-address book. It's a perfect fit.

Brightnorm

I didn't notice the change from the E2 to the A2, except that I use it more due to the two levels. I ALWAYS wish lights were smaller, I guess we just have to wait. I think back to when the Scorpion was the brightest light for the size. Now I think it is still the E2. Maybe the Kl4, in about 2 years will beat it? All I can do is wait...

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Brock said:
.....All I can do is wait...

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That waiting is frustrating but also exciting because of the possibilities.

BN