Lightbulb police? (was RE: Anyone off to VCF-UK)

Philip Pemberton classiccmp at philpem.me.uk
Tue Jun 8 16:14:28 CDT 2010


On 08/06/10 19:31, Tony Duell wrote:
> There were microprocessor (and even microcontroller) projects hack then.
> At least computers based round the SCMP, 6502 (Junior Computer), 2650 (TV
> Games Computer).

Point taken.
But they were the exception rather than the norm.

> I rememebr them saying it was better to store recharageble batteries in
> the discharged state (since they then couldn't self-discharge). There my
> be a battery technology where that's true, but most of the common ones
> are better stored charged.

Store a lithium-ion pack fully discharged and you're asking for trouble 
(if it self-discharges below ~3.5V most chargers won't touch it). 
Wouldn't be surprised if half the "dead" digicam and phone batteries 
were just discharged below the "minimum" mark; a 3.8V PSU with a 10mA 
limit will bring them back into the land of the living in a fairly short 
span of time. Li-ion and Li-polymer are generally best stored about half 
charged.

Not sure about NiMH or Nicad, it's been a while since I read the spec 
sheets.

AIUI Pb-acid and Pb-gel are best stored charged with a monthly top-off 
charge. Leave them on all the time and they sulphate -- or is that 
leaving them discharged? Again, been a while since I skimmed the spec 
sheets.

> Second little hint : None of my cameras has a hard disk, or a CD-ROM
> drive, or...

Let's see what I've got in my kit box...

Olympus OM10: Two SR44s, 35mm film. Have used it in some pretty rough 
conditions.

Olympus OM4 w/ Winder II: Same story, two SR44s, but it eats them MUCH 
faster than the OM10. If I actually cared, I'd replace it with an OM4ti 
or an OM4 Mk.II (which have a newer, low-power controller board). You 
can theoretically use an OM4 with a flat battery, but you're limited to 
1/60sec shutter speed and lose the metering.

I still miss the multi-spot metering on the OM4. That was NICE, and if 
anyone ever ports CHDK to the EOS 7D, I'm adding it (might have to hack 
up live-view mode a bit but who cares!) :)

Canon EOS 33v w/ battery grip: Two CR123 batteries, 35mm film, 
all-electronic. TTL metering, motor drive, autofocus (7-spot), and all 
the bells and whistles you could want. Doesn't balance well with any of 
the "L" series metal-body lenses.

Canon EOS 7D w/ battery grip: Digital. Two lithium batteries in the grip 
(or one if you remove the grip), 18 megapixel APS-C sensor. 8 fps 
continuous burst for 19 shots on RAW (with a suitably fast memory card). 
VERY nice bit of kit, had it since release day (the privileges of 
working in a camera shop) and it hasn't let me down yet.

Have previously owned:
Olympus Trip 35. Let my brother borrow this, he rewarded my generosity 
by smashing the selenium cell. Now the metering is shot to buggery :(

Canon EOS 400D w/ grip. Sold when I upgraded to a 40D
Canon EOS 40D w/ grip. Sold when I got the 7D. New owner asked if he 
could have his money back because he "had a bit of an accident" with 
it... he'd dropped it in a duck pond. Idiot.

>> I'd really like to learn how to do some more advanced
>> plastic/metalworking (and get the tools to do it).
>
> It is great fun. The problem is the startup cost. A good lathe is not
> cheap, but then again it will last all your life if you look after it.

I'm probably going to start with something like a Proxxon MF70 
micro-mill; at the very least it'll be useful for accurately drilling 
and cutting holes in front panels. I can knock holes into metal and 
plastic panels, but I can never get the edges straight, they always look 
a bit bumpy :-/

-- 
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/



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