Aleph A19, which one is right for me?

I would like to buy one of Don's Aleph A19 UV heads, but I'm electronically challenged and don't know which one I need. I want to run it off a single 18650 and one of the McE2S switches that I already have. The switch has a 22ohm resistor. I'm not concerned weather or not there is much difference between output from high to low, I just don't want to damage the A19 curcuit.

Downboy, Wiz2 or Nexgen500?

Thanks for the help.

I don't know anything about the Cree, but I think it's safe to say you don't need a buck converter with a single cell, so the DB is out.

The Wiz2 has issues with pcp resistor value that I don't understand. Suffice to say that the useful range is quite narrow (7 - 15?) and 22ohm is out of spec and probably wouldn't work.

So it looks like you want a NG The shoppe says it's good with R123s and the Cree UV @500mA, so you'd have to assume there are no Vf issues, but if it was me I'd want to know what the story on Vf was for the Cree, for curiosity if nothing else.

I see the Nexgen lists 1x123 (CR123 and R-123). The R-123 would be the same as the 1x18650, except for overall cell capacity correct?

The description also says Nexgens use a 15 ohm 2-stage switch. This really doesn't matter does it? The resistor only controls low level correct? It would just have a brighter low with my 22ohm switch?

Right, the voltage is the same and that's all that matters in this case. The NG has a .7V safe overhead I believe. In other words, if V-in from the battery is higher than the Vf of the LED, it will run in quasi direct drive up to a point (remember it's a boost driver, so in this case there's nothing to boost) with a .7V safety zone. There's also voltage sag to figure in (.3V?) For instance, if the Vin -> Vf relationship put you right on the .7V overhead limit, some might figure that with voltage sag they've still got a little to play with. So you can see that the Vf of the emitter when using a NG can cause a setup to be anywhere from totally safe to probably safe to maybe safe to you might get lucky to it ain't gonna work.

If Wayne says it works at 500mA (it's safer at higher currents like 750-1000 because the Vf effectively goes up) then it must be fine.

You'd have a lower low with 22ohms than with 15 of them.
Apart form that, I *think* you are correct, but with the Cree ... I dunno :shrug:
Better wait for someone who really knows ...
bernie

Bob_G said:

I don't know anything about the Cree, but I think it's safe to say you don't need a buck converter with a single cell, so the DB is out.

The Wiz2 has issues with pcp resistor value that I don't understand. Suffice to say that the useful range is quite narrow (7 - 15?) and 22ohm is out of spec and probably wouldn't work.

So it looks like you want a NG The shoppe says it's good with R123s and the Cree UV @500mA, so you'd have to assume there are no Vf issues, but if it was me I'd want to know what the story on Vf was for the Cree, for curiosity if nothing else.

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It looks like the Wiz2 or the Nexgen will work. I can buy a Wiz2 for $119 or a Nexgen for $150. When you say issue with the pcp resistor, what does this mean? I don't know what the pcp is. I can change the board in my switch to the correct value right?

I have an A19 UV with a Wiz2. I don't find a "low" mode particularly useful with the UV since I'm not really looking for long runtimes with this light, so the tailcap resistor isn't a consideration. The Wiz2 does make use of high capacity Li-ion cells safe.

wasBlinded said:

I have an A19 UV with a Wiz2. I don't find a "low" mode particularly useful with the UV since I'm not really looking for long runtimes with this light, so the tailcap resistor isn't a consideration. The Wiz2 does make use of high capacity Li-ion cells safe.

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I'm still foggy on the whole Li-ion protected/unprotected thing, so I bought the protected cells. No difference right?

It looks like the Wiz2 or the Nexgen will work. I can buy a Wiz2 for $119 or a Nexgen for $150. When you say issue with the pcp resistor, what does this mean? I don't know what the pcp is. I can change the board in my switch to the correct value right?

Click to expand...

That "pcp" was a typo - should be pcb, which of course is the board you refer to with the low resistor. Sure you can change it to another value - if you bought the head from the shoppe you could pick up a proper resistored pcb, or there's guys that will build you one for about 3 bucks. Personally I don't see the point much of the Wiz2, unless a person wanted to run unprotected "R" cells (the Wiz2 has low voltage protection) but I've never been clear if there's really an advantage run-time wise. On primaries, since it's buck/boost, you could use it on either one or two cells, so that might be handy.

Btw, where are you finding one for $119?

lighthoundhttp://www.lighthound.com/sales/aleph.htm

If you choose to use a BBNexgen for your Cree UV light engine, you will initially be overdriving the LED when using Li-ion cells. I don't know how sensitive the Cree part is to overdriving, maybe its just fine. But initially you might find a Li-ion pushing over 1000 mA through that LED, even though its only a Nexgen500 convertor.

I really don't see a downside to the Wiz2 for this application, though you might not fully use up a CR123 primary lithium in single cell configuration if run until convertor shutdown.

Got it today! Very nice little head. Now what should I use it for? I see all kinds of lint in the carpet. OK, I see all kinds of weird stains in the carpet, this is kinda creepin me out. This is the only room in the house that has carpet from the previous owner.

Very, very high quality, me likes!

Now how do get the Ti ringy dingy thingy on without scratchin or bust-a-cate-in something?

Put on some rubber kitchen gloves or something to grip with, shove the bezel into your palm, and twist That woven vinyl jar opener stuff works well - the main thing is to have a good grip on the bezel ring.

That did it! Only took about 30 seconds and the Ti ring found its new home.

Thanks Bob G! You da man!

Ahhh...I like Ti!

Yeah, I love my A19s Love the Ti bezel ring too Wouldn't it be weird if the same guy came up with both? Oh wait ...

Nice photo! What is the no-slip looking black band on your 18650x1?

It's three o-rings - two 017s which fit flush, and one #12 (3/16" thick) which sits up a little. They fit perfect in that depression. The two smaller ones are mostly there to hold the larger one in place, but it makes a nice smooth transition in your hand as well.

I have another one that's different, it just has one 017. I can't remember if I bought this one from you, or someone else, but it's different than the others I have. The knurling is smoother, the gap from the knurling to the adapter is smaller and the button is silver colored. I like the smoother knurling

That was the first one sold. I think you bought that one from Benny. The button is a piece of 6Al-4V Ti.