Products with solar cells

[Joerg]

My guess was always that it served as "reset" -- I've seen solar calculators
"lock up" with bizarre displays due to being left in, e.g., very dim light and
then taken to a bright room.

This one also has a separate clear button. It must contain a nifty
brown-out circuit because this one doesn't hang. It just turns off.
There is a hysteresis between turn on and off light levels.

 

[Joerg]

I always wondered why there isn't any capacity rating on plain
alkaline batteries. They must be closely matched.

There is. But usually not on the sales package, you'll have to go to the
mfg's web site. Their capacity depends on the load and they usually
present several discharge curves as examples.

 

[SioL]

There is. But usually not on the sales package, you'll have to go to the mfg's web site. Their capacity depends on the load and
they usually present several discharge curves as examples.

Great, this bit of info could come handy.

SioL

 

[Joerg]

Great, this bit of info could come handy.

They don't make this stuff easy to find, so here is the relevant section
for Duracell MN:
http://www.duracell.com/oem/Pdf/others/ATB-full.pdf

 

[David DiGiacomo]

On the other hand, if your calculator is powered by a 3-volt CR2032 coin cell
battery with a capacity of 210 mAH, and a cost of about $3, that comes to a
power rate of $4762 per KWHour. I would say that solar wins over batteries in
that comparison.

Retail cost of a CR2032 is closer to $0.20:

http://www.petrusdevices.com/1309.html

You can sometimes get them for less on eBay.

 

[Joerg]

Retail cost of a CR2032 is closer to $0.20:

http://www.petrusdevices.com/1309.html

You can sometimes get them for less on eBay.

If you buy in bulk it's more like $0.15:
http://catalog.digikey.com/scripts/partsearch.dll?Detail?name=P189-ND

 

[Joerg]

A couple hours ago I talked with a guy who spent $7 for a single
replacement button cell to power a $19 instrument. There are some very
high prices for convenience out there.

I hope they poured him a nice cup of coffee, ahm, Java. At least there
we have choices. When it comes to stuff like pool equipment you usually
don't. I just replaced the leaf bag on our pool sweep which cost a
whopping $32 or so. Days later the hose broke. Which, of course, is a
custom piece again. Talking about profit margins I guess we are all in
the wrong business.

 

[Spehro Pefhany]

If you buy in bulk it's more like $0.15:
http://catalog.digikey.com/scripts/partsearch.dll?Detail?name=P189-ND

A couple hours ago I talked with a guy who spent $7 for a single
replacement button cell to power a $19 instrument. There are some very
high prices for convenience out there.


Best regards,
Spehro Pefhany

 

[Henry Kiefer]

| I hope they poured him a nice cup of coffee, ahm, Java. At least there
| we have choices. When it comes to stuff like pool equipment you usually
| don't. I just replaced the leaf bag on our pool sweep which cost a
| whopping $32 or so. Days later the hose broke. Which, of course, is a
| custom piece again. Talking about profit margins I guess we are all in
| the wrong business.

Answer: True!

- Henry

 

[Richard The Dreaded Libertarian]

Talking about profit margins I guess we are all in
the wrong business.

Talking about profit margins, I've been seriously considering making
a little pill mold and getting some blue-green powdered sugar and
selling counterfeit Viagra. ;-)

For one thing, it'd be interesting to see the potential placebo effect,
and for the other, who are they going to complain to about black market
viagra if it doesn't work? ;-)

Cheers!
Rich

 

[Mike]

kinda poor. But completely non-functional? That seems unlikely.

I've got one of those -- it's a desktop calculator with "big buttons". It
takes batteries. It runs exclusively on those batteries, they are not a
backup. The front of the calculator has a graphic representation of a solar
cell printed on it (4-5 brown squares with gold bits between). It's just
a picture, it's not electrically functional. It also has a little "sun" icon
on the box, and claims solar power.

Too cheap to be bothered returning it as "not as described" or "unfit
for intended purpose". It worked, solar wasn't really a requirement, and it
just struck me as a rather dumb thing to do.

Have you not seen the "non-functional" shake-to-power torches? Real ones
have a rare-earth supermagnet, coil, rectifier, capacitor etc. Fake ones
have a piece of shiny metal bar ("magnet") a coil of wire (not connected), and
a non replaceable battery ("capacitor"). Crazy ...

 

[Joel Kolstad]

Have you not seen the "non-functional" shake-to-power torches?

I've read about them; I was surprised that building a fake is actually cheaper
than buildling the real things!

 

[Henry Kiefer]

| In article <[email protected]>,
|
| >kinda poor. But completely non-functional? That seems unlikely.
|
| I've got one of those -- it's a desktop calculator with "big buttons". It
| takes batteries. It runs exclusively on those batteries, they are not a
| backup. The front of the calculator has a graphic representation of a solar
| cell printed on it (4-5 brown squares with gold bits between). It's just
| a picture, it's not electrically functional. It also has a little "sun" icon
| on the box, and claims solar power.
|
| Too cheap to be bothered returning it as "not as described" or "unfit
| for intended purpose". It worked, solar wasn't really a requirement, and it
| just struck me as a rather dumb thing to do.

Plastics is made of hydrocarbon and that was alife a long time ago. Powered and grown by sun. So it "was" sun-powered or simply
solar ;-)

- Henry