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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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On 6/4/2010 1:22 PM, Orchid XP v8 wrote:
> 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 have one about the size that you mentioned. It's a neon sign
transformer that puts out several kilo-volts. I used to have it hooked
up to a rather large Tesla coil. The coil was dismantled many years
ago, but I still held onto the transformer, just in case. ;-)
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Kyle wrote:
> On 6/4/2010 1:22 PM, Orchid XP v8 wrote:
>> 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 have one about the size that you mentioned. It's a neon sign
> transformer that puts out several kilo-volts. I used to have it hooked
> up to a rather large Tesla coil. The coil was dismantled many years
> ago, but I still held onto the transformer, just in case. ;-)
I would imagine that to HOLD ON TO a transformer like that would be...
inadvisible. (!)
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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Orchid XP v8 wrote:
> Kyle wrote:
>> On 6/4/2010 1:22 PM, Orchid XP v8 wrote:
>>> 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 have one about the size that you mentioned. It's a neon sign
>> transformer that puts out several kilo-volts. I used to have it
>> hooked up to a rather large Tesla coil. The coil was dismantled many
>> years ago, but I still held onto the transformer, just in case. ;-)
>
> I would imagine that to HOLD ON TO a transformer like that would be...
> inadvisible. (!)
>
Only while there is still some power left in it.
That kind of voltage and current is safe if you respect it. Had a
impromptu band play on campus, where the bass line was a jacob's ladder
sticking out of the back of a microwave. The drum stick was a metal tip
glued on to a good length of acrylic. No Tesla coils, yet.
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> 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...
People who have moved from 110V countries to 220V ones (or vice versa) often
have a chunky transformer like that so they can run their old equipment.
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Invisible wrote:
> ... although I also found ... a small bottle of white powder marked
> "KNO3"...
A little charcoal and sulfur and *you* *are* *in* *business* *!*
> 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 electronic characteristics...)
A capacitor consists of a piece of electrolytic material sandwiched
between two conducting plates. The capacitance is proportional to the
area of the plates, is inversely proportional to the distance between
the plates, and is factored by the capacitance of the electrolytic
material between the plates. To get up to where capacitance is measures
in farads (instead of microfarads), you need large plates, the thinnest
possible spacing between them, and the best material to go between (as
to which material is the best, I am not in the know). The most reliable
manufacturing technique is to take a thin layer of flexible electrolyte,
plate it with metal on both sides, insulate one of the two sides, and
roll the plates up so that they take less room.
If they're old components, it may be that manufacturing techniques
didn't allow the two plates of the cap to be closer together. To make
up for a lack of precision, you have to increase the area of the plates.
It all comes down to how thin the electrolyte can be and still
physically separate the two plates (because if the plates make
electrical contact, the cap becomes a wire).
> 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!
Good. Now you should be able to build a small, functioning processor.
With pretty lights to show the data states.
Regards,
John
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>> ... although I also found ... a small bottle of white powder marked
>> "KNO3"...
>
> A little charcoal and sulfur and *you* *are* *in* *business* *!*
And why did you *think* my dad had this? ;-)
>> 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!
>
> Good. Now you should be able to build a small, functioning processor.
> With pretty lights to show the data states.
Negative.
I tried to solder the LEDs to a board, but for reasons beyond my
comprehension, there's a short-circuit somewhere. I've checks and
re-checked the board. I can't see the short. But there is one.
I think I need to go buy some solder that isn't 30 years old...
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On 6/7/2010 9:11 AM, Invisible wrote:
>
> I tried to solder the LEDs to a board, but for reasons beyond my
> comprehension, there's a short-circuit somewhere. I've checks and
> re-checked the board. I can't see the short. But there is one.
You know... a $15 multimeter with a continuity tester ....
Heh. I proudly proclaimed to my dad that I just repaired my USB
thumbdrive's connector all by myself.
His first response was "Does it still work?"
It does! Hehe.
--
~Mike
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>> I tried to solder the LEDs to a board, but for reasons beyond my
>> comprehension, there's a short-circuit somewhere. I've checks and
>> re-checked the board. I can't see the short. But there is one.
>
> You know... a $15 multimeter with a continuity tester ....
I have one. That's how I know there's a short circuit. I just can't
figure out *why*.
When I was soldering one of the components, the solder spilt onto the
adjacent track. I've tried to fix at a dozen times now, but I'm still
getting continuity somehow...
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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On 6/7/2010 1:56 PM, Orchid XP v8 wrote:
>
> When I was soldering one of the components, the solder spilt onto the
> adjacent track. I've tried to fix at a dozen times now, but I'm still
> getting continuity somehow...
>
Do you have some copper braid or a solder pump? that should clean it off.
--
~Mike
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>> When I was soldering one of the components, the solder spilt onto the
>> adjacent track. I've tried to fix at a dozen times now, but I'm still
>> getting continuity somehow...
>>
>
> Do you have some copper braid or a solder pump? that should clean it off.
There was a blob of solder between the tracks. So, as per the
instructions in my trusty old electronics book, I ran the point of the
iron down the groove between the tracks.
In three cases, this fixed the problem. In the forth case, a short
circuit still exists somehow.
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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On 07/06/2010 7:51 PM, Mike Raiford wrote:
> On 6/7/2010 9:11 AM, Invisible wrote:
>
>>
>> I tried to solder the LEDs to a board, but for reasons beyond my
>> comprehension, there's a short-circuit somewhere. I've checks and
>> re-checked the board. I can't see the short. But there is one.
>
> You know... a $15 multimeter with a continuity tester ....
>
Or eyes for solder blobs,
> Heh. I proudly proclaimed to my dad that I just repaired my USB
> thumbdrive's connector all by myself.
>
> His first response was "Does it still work?"
>
> It does! Hehe.
>
>
:-D
--
Best Regards,
Stephen
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On 07/06/2010 8:02 PM, Orchid XP v8 wrote:
>>> When I was soldering one of the components, the solder spilt onto the
>>> adjacent track. I've tried to fix at a dozen times now, but I'm still
>>> getting continuity somehow...
>>>
>>
>> Do you have some copper braid or a solder pump? that should clean it off.
>
> There was a blob of solder between the tracks. So, as per the
> instructions in my trusty old electronics book, I ran the point of the
> iron down the groove between the tracks.
>
> In three cases, this fixed the problem. In the forth case, a short
> circuit still exists somehow.
>
A sharp knife or a scalpel works wonders.
You need the right tools to do the job.
--
Best Regards,
Stephen
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Stephen wrote:
> You need the right tools to do the job.
Hence my suggestion that I should buy some solder that isn't 30 years
old. (I suspect my iron also needs a new tip...)
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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On 07/06/2010 8:17 PM, Orchid XP v8 wrote:
> Stephen wrote:
>
>> You need the right tools to do the job.
>
> Hence my suggestion that I should buy some solder that isn't 30 years
> old. (I suspect my iron also needs a new tip...)
>
You can file it, then tin it. But new tips are a good idea.
--
Best Regards,
Stephen
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