recovering old NiCd battery pack for cordless phone

[Big Bad Bob]

(OBHACK is the post)

I have an old cordless phone that I don't want to replace. NiCd battery
pack (3 cells) ended up with 1 bad cell, so I checked Target for a
replacement. They want about $20. On-line it's less than $5 but I have
to wait a week or so. So I order the replacement on-line ANYWAY, and
then found THIS web site:

http://webhowto.htmlplanet.com/nicad.html

So I grab a giant capacitor off the boneyard shelf, charge it up
repeatedly to 12V with a bench power supply, "zap" the battery with the
capacitor, re-charge, repeat, etc. until the 'discharged' voltage on the
capacitor is in the 3.3V range - TADA! Got the cell un-shorted!

I'm now using bench power supply to charge battery pack at around 100ma,
should be ok in a few hours, and then I'll have a working cordless phone
until the new battery pack arrives. I may keep the old one anyway, as a
'spare'.


ANOTHER nice webcam hack: using a cardboard toilet paper tube, a white
LED, and a lupe to create a kind of 'lighted macro lense' for a webcam.
Oh, yeah, need to tape it all together with packing tape or duck tape
(your choice). Tube had too large of a diameter, so I slit it down the
side, "custom fit" to the lupe, tape nice and tight. A bit of tinfoil
on the 'object' side of the lense (around the LED) helps to diffuse the
light, though you see a bit of a 'corona' effect in the reflection.
Still works for its intended purpose, though. Focus is set to the edge
of the cardboard, so you could literally set it on top of something and
get a closeup camera view, maybe ant cam or spider cam or flower cam or
nose-hair cam or ?

[Eli the Bearded]

In alt.hackers, Big Bad Bob <BigBadBob-at...@testing.local> wrote:
> ANOTHER nice webcam hack: using a cardboard toilet paper tube, a white
> LED, and a lupe to create a kind of 'lighted macro lense' for a webcam.

Instead of cardboard toilet paper tubes, the do-it-yourself lenses I've
seen use PVC pipe a lot. Another nice material is sections of bicycle
inner tube, not good for long lengths, but the flexibility makes changing
the focus doable.

> of the cardboard, so you could literally set it on top of something and
> get a closeup camera view, maybe ant cam or spider cam or flower cam or
> nose-hair cam or ?

Macro lenses are all sorts of fun in my opinion.

ObHack: I took a nice pair of binoculars and made a telephoto for a
point and shoot digital camera from them, without permanently modifying
the binoculars. I strapped the binoculars to a scrap of wood with a
length of bike inner tube, then made a new "eye cup" out of more inner
tube and a cable tie. Then I figured out where the camera should be
and put a bolt through the plank in just the right spot to attach to
the tripod mount. It worked, although it was hard to use.

A photo of the setup:

http://www.flickr.com/photos/elithebearded/5066184560/

Photos I took using it:

http://www.flickr.com/photos/elithebearded/sets/72157624965753079/

(The dirt is on the inside of the point and shoot lens. There's a reason
that camera was available for such games.)

Elijah
------
has been meaning to try making complete lenses for a while