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Cyparagon

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Yep. 10.5 is AA.. He said AAA...
Sorry, I forgot an A. AAs are 14mm. AAAs are 10.5mm.

i think (well i hope) he meant that you can fit an 18650 into a 3AAA cartrige spot.
That doesn't work out either. 18650s are 65mm long, and the 3xAAA battery carriage I have is only 53mm long.

The Energizer lithiums....
Those aren't exactly cheap.

you just recharge 'em from the grid"... what grid do you have that is free?
The charger I have uses about 5W. Let's say it takes 2 hours to charge a battery. That's 0.12 cents per charge which is practically free.
 

chipdouglas

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^^^ well if you grew up with a penny pinching jewish dad like did, then that is .12 cents too much LoL.


michael
 

LazyBeam

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AAA lithiums can be cheap. The generic ones are about $1.25ea for ~1800mWh.
For comparison, Duracell alkalines are about $0.21 for ~1800mWh (but only @ ~750mA).

10440 batteries are about $3.50ea for ~1800mWh with +$0.12/charge.
Plus a charge, which would be about $10.

The break even point is about 12 charges for a 10440 versus a lithium primary.
Although, I don't think people have to worry about lithium Priaries blowing up.

The break even point is about 150 charges for a 10440 versus an Alkaline primary.
Obviously, Alkalines won't ever blow up and are extrememly common/easy to find.
For diodes drawing under ~500mA@4.5V Alkalines are a very economical choice.
 

Blord

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$0.12/charge is alot. Where I came from that is worth 500Watt usage in 1 hour ( 1KWh=€0,20). No way that a 10440 charger will consume that much energy.

A typical 10440 rechargeable battery holds 300mAh. With the 3.7V of the battery that is 3.7x300mAh= ~1Watt per hour. The electricity price is €0,20 per 1KWh. This means 1Wh cost 0.02 euroCENT.

It cost 0,02cent per charge. I haven't calculated the losses in the charging process.

150 charges costs about 3cent
 
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Cyparagon

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10440 batteries are about $3.50ea for ~1800mWh with +$0.12/charge.
Plus a charge, which would be about $10.
Not 12¢, 0.12¢. Electricity here is about 12¢/KWh. My charger uses 5W and can charge an 18650 in about 2 hours which is 0.12¢. For a 1.8Wh battery and a 90% efficient charger, and a 66% charge efficiency (to over-estimate cost), it would use 3W for 1 hour, which is $0.00036 or 0.036¢. Either way, this is NOTHING in the grand scheme of things. Find a quarter in your couch, and you've payed for battery charging for the rest of your life. ;)

Even if it were 12¢, how does $3.50 + $3.50 + $0.12 + $0.12 = $10? That's $7 for two. The break-even point is 3 cycles vs. lithiums. For alkalines, it would be 17 cycles assuming your prices were accurate.
 
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All the laser pointers I've seen are red, but it doesn't really matter because cats can't see red anyway. What they see is the movement. You can get the same effect with a tight flashlight beam.
 

qumefox

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Cats can see red just fine. I think what you mean is that cats can't differentiate between different shades of red very well. They usually aren't colorblind however, and can tell the difference between red and other colors, but the general consensus is that while cats can see farther into the IR range than we can, they see better on the blue/violet end of the spectrum. My cats, for example, while I know they can see 660 since they watch it, most of the time they won't chase it, only watch the dot move.. When I use a low power 405 though, they scamper after it every time.
 

suthnland

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New member here with a couple of questions if you dont' mind.

I currently use lasers for the detection of metalic particles in a liquid and am becoming increasingly frustrated with their unreliability and/or functionality.

For all the lasers I use, I've discovered they ALL act in a similar fashion, ie; if I rotate my wrist whilst shining the laser through the liquid the beem either diminishes or is enhanced, dependant on extent of wrist rotation. In fact, one will shine a spot on the wall but fail to illuminate the metalic particles as the beam passes through the liquid, others do, but this particular one doesn't? It seems to me that lasers must be of particular construct so as to be reliable and accurate in their functionality.

I know nothing about electronics etc but I am led to believe 'collimation' is of the utmost importance. If I shine the light on the wall I can detect several small 'spots' arranged in a circle...this I am also led to believe is how lasers actually work, ie; it's not one 'spot' but several arranged in a circle. As I withdraw the laser further from the wall I notice an area whereby the light tends to spread from one point of area from that localised circular pattern...like a bleeding of light at a particular point from those circular small 'spots' on the wall. Example: if there are six small dots of light arranged in a circular pattern, only five will 'spot' and one will spread light out from that circular arrangment of spots.

Apologies if I'm not making myself clear but I can't think of any other way of explaining it.

Could someone point me {no pun intended} to a reasonable quality laser pointer which emits light as it should...or do they ALL have these idiosyncrasies.

I understand one can make their own laser pointer, and praps one day I'll see if I can get someone to build one for me. I don't want one that's capable of burning a hole in the moon landscape, just one that actually functions with some reliability that I can *trust* for the purpose for which I use a laser pointer.

I have done some limited reading and there seems to be mention of a 'driver' or something, would/could this be the reason for those - what I consider El Cheapo lasers -not functioning as I thought they should, or would?

Your forum may be more suited to those who are involved with disco's, or light shows etc, but I thought it was worth asking you people anyway.

Thanks

N.

P.S. Perhaps I could/should look around and see if I can get hold of a small light show laser or something which may serve my purpose?
 

anselm

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Well maybe if you told us in more detail what exactly your intended purpose is,
other than shining it at particles suspended in liquid.

Maybe you should start a new thread about that instead of changing the subject of this one. ;)
 

suthnland

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Yep, you're right, sorry for the intrusion, perhaps one of your moderators would be so kind as to remove my posting.
 




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