On Monday, my father and I went on a little father-and-son expedition to 
the outer reaches of his loft. We found some really far-out stuff up 
there. Most of it was to do with electronics, although I also found a 
gas cylinder marked "CO2", and a small bottle of white powder marked 
"KNO3"...

Some capacitors are small brown things like little chocolate buttons. 
(But significantly less tasty.) Then there's the "electrolytic" ones, 
which are small blue things that look like they belong in a licorish 
all-sorts bag. Some a really small (about 5mm diammeter). Some are a bit 
bigger (15 mm diammeter).

When I was in my dad's loft, I found capacitors the size of friggin' 
soda cans! o_O WTF are *those* for??

(I mean, are they that size because they have a higher capacitance or 
something? I gather a capacitor is one of the few components where the 
physical size of the device determines its electronical characteristics...)

Also, most transformers are small square lumps about the size of your 
thumb. (Then again, you use them on 5V electrics.) I saw a transformer 
up there that was about 15cm along all three edges. Presumably in this 
case the size is to allow it to handle higher current without melting.

And then there were the transistors. Normal transistors are tiny black 
plastic cylinders with long legs. Occasionally you'll see a transistor 
that's metal and slightly fatter. But my dad showed me some transistors 
which were about 4cm across, bolted to a heat sink the size of my car's 
radiator. Apparently these are "power transistors". o_O

We also found a box containing more 14-pin DIL sockets then it is 
humanly normal to have. And a bunch of 7400-series chips. In particular, 
these are the original, obsolete, 7400 chips. 7400, 7408, 7402, etc. Not 
74LS00 or even 74S00, but vanilla 7400 TTL. They're that old.

We also found a stack of unopened boxes containing LEDs. Now when I was 
at Maplin I bought a bag of mixed LEDs - which is great, because you get 
a lot of LEDs for not much money, but OTOH they're all different. Now I 
have a matching set!

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On 2010-06-04 05:22, Invisible wrote:
> Some capacitors are small brown things like little chocolate buttons.
> (But significantly less tasty.) Then there's the "electrolytic" ones,
> which are small blue things that look like they belong in a licorish
> all-sorts bag. Some a really small (about 5mm diammeter). Some are a bit
> bigger (15 mm diammeter).
>
> When I was in my dad's loft, I found capacitors the size of friggin'
> soda cans! o_O WTF are *those* for??
>
> (I mean, are they that size because they have a higher capacitance or
> something? I gather a capacitor is one of the few components where the
> physical size of the device determines its electronical characteristics...)

My dad would bring home/have all sorts of sizes of stuff like that. 
Probably still has an arbitrary mass of otherwise unidentifiable 
components.  (He worked at GTE Airfone for most of my childhood.)  The 
bigger capacitors would go with heavier-duty electronics...a good UPS, I 
imagine, probably has one or more of them.

Guess it just depends what sub-branch of electrical engineering your dad 
is into and you get to see as a kid.

--
Tim Cook
http://empyrean.freesitespace.net

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Hmm, what to do with all that stuff. Caps, power transistor, and a few
transformers.

I know!

Railgun!

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On 6/4/2010 6:24 AM, Sabrina Kilian wrote:
> Hmm, what to do with all that stuff. Caps, power transistor, and a few
> transformers.

Hehe... with a handfull of caps, some diodes and a 555 timer as the 
clock source, you can create your very own chargepump.

(Plug it into http://www.falstad.com/circuit)

$ 1 5.0E-6 10.20027730826997 50 5.0 50
d 144 112 192 112 1 0.805904783
d 192 112 240 112 1 0.805904783
d 240 112 288 112 1 0.805904783
d 288 112 336 112 1 0.805904783
c 192 112 192 208 0 1.0E-5 4.466071842606139
c 240 112 240 256 0 1.0E-5 8.960381260256856
c 288 112 288 208 0 1.0E-5 8.419397603519451
c 528 112 528 256 0 1.0E-5 20.732461600283102
g 336 256 336 336 0
w 432 256 336 256 0
w 336 256 240 256 0
w 288 208 192 208 0
w 192 208 144 208 0
R 144 112 80 112 0 0 40.0 5.0 0.0 0.0 0.5
R 144 208 80 208 1 2 10000.0 2.5 2.5 0.0 0.5
w 528 112 608 112 2
w 288 208 384 208 0
c 336 112 336 256 0 1.0E-5 12.870708825821993
c 384 112 384 208 0 1.0E-5 12.322975506019386
c 432 112 432 256 0 1.0E-5 16.78270116633109
c 480 112 480 208 0 1.0E-5 16.250773941269088
w 432 256 528 256 0
w 384 208 480 208 0
d 336 112 384 112 1 0.805904783
d 384 112 432 112 1 0.805904783
d 432 112 480 112 1 0.805904783
d 480 112 528 112 1 0.805904783


-- 
~Mike

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Mike Raiford wrote:

> Hehe... with a handfull of caps, some diodes and a 555 timer as the 
> clock source, you can create your very own chargepump.

This, apparently, is why USB flash drives can work. They use a charge 
pump to generate the large voltages needed to erase a block prior to 
reprogramming it.

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Wow.  I kind of feel sorry now for all the people who grew up after ICs were 
common and don't know how capacitors work or what a power transistor is for.

-- 
Darren New, San Diego CA, USA (PST)
    Eiffel - The language that lets you specify exactly
    that the code does what you think it does, even if
    it doesn't do what you wanted.

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Darren New wrote:
> Wow.  I kind of feel sorry now for all the people who grew up after ICs 
> were common and don't know how capacitors work or what a power 
> transistor is for.

Any specific reason?

Anyway, I only work with low-power electronics, so I don't know a whole 
heap about how to engineer (say) the lifting motors for a gigawatt damn 
sluce.

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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On Fri, 04 Jun 2010 10:22:44 +0100, Invisible wrote:

> Also, most transformers are small square lumps about the size of your
> thumb.

I'm about to blow your mind:

http://www.google.com/images?hl=en&source=imghp&q=power
+transformer&gbv=2&aq=f&aqi=&aql=&oq=&gs_rfai=

Jim

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>> Also, most transformers are small square lumps about the size of your
>> thumb.
> 
> I'm about to blow your mind:
> 
> http://www.google.com/images?hl=en&source=imghp&q=power
> +transformer&gbv=2&aq=f&aqi=&aql=&oq=&gs_rfai=

Yeah, well *obviously* a transformer than supplies 20,000 homes is going 
to be slightly bigger than the one that supplies the 20 mA to the 
speaker in your pocket radio. :-P

The thing is, you don't have a transformer like that IN YOUR HOUSE. And 
yet, my dad for some reason DOES have this monster transformer...

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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On Fri, 04 Jun 2010 18:22:04 +0100, Orchid XP v8 wrote:

>>> Also, most transformers are small square lumps about the size of your
>>> thumb.
>> 
>> I'm about to blow your mind:
>> 
>> http://www.google.com/images?hl=en&source=imghp&q=power
>> +transformer&gbv=2&aq=f&aqi=&aql=&oq=&gs_rfai=
> 
> Yeah, well *obviously* a transformer than supplies 20,000 homes is going
> to be slightly bigger than the one that supplies the 20 mA to the
> speaker in your pocket radio. :-P
> 
> The thing is, you don't have a transformer like that IN YOUR HOUSE. And
> yet, my dad for some reason DOES have this monster transformer...

I do have a pretty good sized transformer in a PSU for an amateur radio 
rig in the basement.

Jim

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