Foom
Robert McCown
Sitting at my desk today, in the middle of some important work[1], I get a
whiff of Magic Smoke (tm). A quick run to the rack doesnt show any, nor any
dead hardware, but the smell is stronger her. While rummaging around, the
JngpuThneq Sverobk 6gp flashes every LED on its front panel, then gets
reassigned to titsup.com. Lots more Magic Smoke.
Phark, but at least I have a spare (or two). Plug one in, and, you guessed
it. Same thing. Instant Foom.
Double Phark. Whip out the multimeter, and check the wall wart output.
Hmm, a tad high[2]. Throw wall wart across room[4], take out NEW wall wart,
plug in, test, HEY, good V+.
Total downtime: about 5 minutes. Total damage: 2[3] dents in far wall.
[1] game of bzFlag
[2] FSVO 'tad high' nearing 120v
[3] one wall wart, one box
[4] now, where's that spackle?
--
Bob McCown - rmc...@world.std.com
| When I win the lottery, I'm going to fund a Wile E. Coyote Chair of
| Applied Engineering at some university, I am... - John Robinson
st...@madcelt.org
> Sitting at my desk today, in the middle of some important work[1], I get a
> whiff of Magic Smoke (tm). A quick run to the rack doesnt show any, nor any
> dead hardware, but the smell is stronger her. While rummaging around, the
> JngpuThneq Sverobk 6gp flashes every LED on its front panel, then gets
> reassigned to titsup.com. Lots more Magic Smoke.
> Phark, but at least I have a spare (or two). Plug one in, and, you guessed
> it. Same thing. Instant Foom.
> Double Phark. Whip out the multimeter, and check the wall wart output.
> Hmm, a tad high[2]. Throw wall wart across room[4], take out NEW wall wart,
> plug in, test, HEY, good V+.
> Total downtime: about 5 minutes. Total damage: 2[3] dents in far wall.
> [1] game of bzFlag
> [2] FSVO 'tad high' nearing 120v
> [3] one wall wart, one box
> [4] now, where's that spackle?
Similar story that happened to me recently:
Developer hands me a bag with 2 wall warts and 2 modems. Neither modem has
any information on it about power consumption or anything useful like that[5].
Taking a guess I plugged wall-wart{1} into modem{1}. It worked fine. Cool.
Stupidly assuming this must mean the other wallwart belongs to the other modem
I plug it in and turn it on. You guessed it, magic smoke released. Shiiiiittttt!
If the Gods hadn't had enough fun with me then, they certainly have now. I'm
in the middle of moving a stack of flexlm licenses from one server to another.
I'm sure this is going to pay off some of that bad karma I seem to have accumulated.
[1-4] NMF
[5] one didn't even have a manufacturer label
--
Stevo st...@madcelt.org
It could be worse - a friend of mine was taught French by a
native Glaswegian. His French accent is, let's just say,
'interesting'. -Tanuki-
Shalom Septimus
>> Double Phark. Whip out the multimeter, and check the wall wart output.
>> Hmm, a tad high[2].
>> [2] FSVO 'tad high' nearing 120v
>Similar story that happened to me recently:
Oh, higher than expected voltage stories time is it?
I was helping my aunt clean out her basement, some years ago; after
living there for some twenty years, the basement had more clutter than
she needed. I found an old tape recorder, from back in the days when
personal tape recorders used 1/4" tape on 3" reels, and operated from
either batteries or a wallwart.
I wanted to see if this thing worked, so went looking for an outlet.
Nearest outlet I could find was on the wall separating the finished part
of the basement from the bit that had the boiler, washer/dryer, etc. I
plugged the thing in and turned it on; there was a "CLICK!" from the
speaker, and no further action. Hmm, says I, it's probably b0rken, and
threw it out with the rest of the junk.
Some time later, I needed to look in an unlighted area of the basement,
so I dragged out the drop lamp that her ex had left there (he was a
mechanic), and plugged it into the outlet. The bulb promptly went off
like an M5 flash.
All right, WTF? Pulled out the multimeter and stuck the leads in the
outlet.
208VAC. [1] WT*F*?
At this point, I went and looked at the number plate on the air
conditioner that had been plugged into this ordinary NEMA 5-15R socket,
and sure enough, it was rated at 208/230 volts.
It seems that at some point in the distant past, someone had installed
an air conditioner there, through an interior wall no less -- the ass
end of the machine stuck out into the unfinished area, I guess he didn't
care how hot that got -- and then this luser took a needle-nose plier
and twisted the prongs around on the plug so it would match the socket,
rather than go out and buy the right socket for that voltage rating.
This is a disaster waiting to happen, says I. I went looking for the
circuit breaker to shut off power to this outlet so nothing else would
get fried, but I couldn't find any 15-amp double-gang breakers in the
box. I went upstairs and asked my aunt, "Where does the power for that
air conditioner in the basement come from?" She said, "Oh, it's on the
same line as the one upstairs."
WT**F**?!
(The unit upstairs was an enormous machine that cooled the entire floor;
IIRC it was rated at 28,500 BTU, and was on its own line fused at 30
amps. It seems that when they put the basement A/C in, they daisy-
chained their line straight down from that socket. This means that the
socket in the basement is essentially unfused, or put another way, the
twenty foot run of 14-gauge BX cable is the fuse.)
I left a piece of tape covering the socket with "Do Not Use" written on
it. My aunt moved out of that house about ten years ago. As far as I
know, it hasn't burned down yet.
[1] this was in nyc.ny.us, where the nominal voltage is 117.
--
Shalom
Robin Munn
>
> It seems that at some point in the distant past, someone had installed
> an air conditioner there, through an interior wall no less -- the ass
> end of the machine stuck out into the unfinished area, I guess he didn't
> care how hot that got -- and then this luser took a needle-nose plier
> and twisted the prongs around on the plug so it would match the socket,
> rather than go out and buy the right socket for that voltage rating.
You know, there's something I've been trying to figure out for months.
This past summer, I took part in a volunteer program teaching English in
China, not too far from Shanghai. It was quite hot in the daytime (peak
temperatures approaching a hundred Fahrenheit, ninety-plus percent
humidity) and the classrooms weren't air-conditioned, but for the
comfort of the visiting Americans, our break room was a conference room
with an air conditioner in the corner. A rather effective one, too:
stepping out of the heat and into the cool room felt like walking into a
refrigerator, what with the relative temperature difference.
But what puzzled me was the air conditioner. It was a *free-standing
unit*, about six feet tall by two feet by two feet or so, that could
easily be carried into a room and plugged in. A vent at the top of the
unit blew air over a whole lot of cooling fins, and the rest of the unit
was sealed. I couldn't figure out where in the world the heat was
supposed to go. I don't think the unit was actually attached to anything
except its power cord: I remember nudging it to see if it was bolted
down, and it could slide across the floor freely. And I also remember
checking behind the unit to see if I could feel hot air behind it, and
not feeling any. As far as I could tell, the thing *should not have
worked*. But it unquestionably did.
That particular type of air conditioner -- free-standing, as opposed to
the boxes-mounted-in-windows-or-walls that you find here in the States
-- seemed to be everywhere I looked in China: grocery stores, people's
homes (several of the American teachers were invited to students' homes
for refreshments and English conversation). And everywhere, there was no
question that they were effective at cooling the air inside the room
they were placed in. But *where was the heat going*? I still can't
figure this one out.
Do any monks have any knowledge of the kind of air conditioning unit I'm
describing? How does it work?
--
Robin Munn <rm...@pobox.com>
http://www.rmunn.com/
PGP key ID: 0x6AFB6838 50FF 2478 CFFB 081A 8338 54F7 845D ACFD 6AFB 6838
Mike Andrews
Could it have been a "swamp cooler", so-called: a box that cools
air by blowing it over a water-soaked porous belt? Those generate
only the heat from the motors moving the belt and the fan, and
were pretty common in the central US until air conditioning got
cheap enough for the masses. Were the cooling fins being wetted
continuously from a source inside the box?
--
I see that your skrode is not running current-level code for one
or more functions. Just a minute. There! Now, go update the code
of every skrode you happen upon. Welcome to our Brave New Bligh^W
Universe. And don't feel compelled to do any of this. Just do it.
Satya
<mi...@mikea.ath.cx> wrote:
> Could it have been a "swamp cooler", so-called: a box that cools
Is this different from a "desert cooler"? ISTR desert coolers require
low ambient humidity. ICBW, but maybe desert coolers simply blow humid
air, while swamp coolers blow air cooled by evaporation of water.
Perhaps in the swamp cooler, the water comes from the humidity in the
air.... Nah, I still don't see where the heat is going.
--
Satya.
James Vandenberg
> On 15 Jan 2003 23:57:44 GMT, st...@madcelt.org wrote:
>
>>> Double Phark. Whip out the multimeter, and check the wall wart output.
>>> Hmm, a tad high[2].
>>> [2] FSVO 'tad high' nearing 120v
>
>>Similar story that happened to me recently:
>
> Oh, higher than expected voltage stories time is it?
Not a HTEV story, but a me-being-a-luser story. Once, there was a
powersocket in the shed. It was a normal 240V socket. Except there had
been a number of lamps go pop from that socket. Me, being the idiot 14
year old that I was, stuck in the leads from my $20 el-cheapo
multimeter, and flicked the switch.
I Got Bit.
Luckily the current went across my hand, rather than across my body, but
it hurt a bit. I can remember not being able to drop the multimeter, I'm
not sure how I actually got out of it. I think I just pulled away from
the socket, disconnecting the leads. Now why this multimeter bit me is
because it was a peice of crap, and a dangerous peice of crap. It had
some really shoddy soldering on the inside (not my own) so that the
screws on the back plate were touching the input lines. As well as
this, they were proud of the surface, leaving two nice little terminals
where a hand would go.
I learnt two important lessons from this: Check _Everything_ when dealing
with dangerous stuff, and Don't Buy Obvious Crap.
Incidently the socket was bang on 240V, +/- the error in the multimeter,
which I expect was non-trivial.
Ja-PHBs-with-a-lust-for-power?-plug-em-into-a-wall-socket!-mes
--
James Vandenberg Email: james at vandenberg.dropbear.id.au
GPG FP= 65AB 179A D884 EDC6 216D FE6A 6833 02BC 4425 4F70
Quidquid latine dictum sit, altum videtur. ICQ: 151135390
Beware! Sometimes forks and candles fall from the sky.
Rick Dickinson
alleged to have written:
>You know, there's something I've been trying to figure out for months.
>But what puzzled me was the air conditioner. It was a *free-standing
>unit*, about six feet tall by two feet by two feet or so, that could
>easily be carried into a room and plugged in. A vent at the top of the
>unit blew air over a whole lot of cooling fins, and the rest of the unit
>was sealed. I couldn't figure out where in the world the heat was
>supposed to go. I don't think the unit was actually attached to anything
>except its power cord: I remember nudging it to see if it was bolted
>down, and it could slide across the floor freely. And I also remember
>checking behind the unit to see if I could feel hot air behind it, and
>not feeling any. As far as I could tell, the thing *should not have
>worked*. But it unquestionably did.
>Do any monks have any knowledge of the kind of air conditioning unit I'm
>describing? How does it work?
It sounds like you are describing what is usually called a "swamp
cooler", aka an "evaporative cooler". Rest assured, they fail to
violate conservation of energy.
They work by blowing warm air across (or through) a dampened filter.
Some of the heat energy from the air goes into evaporating some of the
water, and you end up turning hot air into cooler, but more humid,
air.
We had one when I was a kid, living in the Mojave Desert area. They
work best, as you can imagine, when the air is fairly dry to start
with.
Of course, the box *could* simply have Maxwell's demon inside it.
- Rick "Wearing my sorting hat" Dickinson
--
Build a man a fire, and he will be warm for a day. Set a man on fire,
and he will be warm for the rest of his life.
jgut...@brokersys.com
> It sounds like you are describing what is usually called a "swamp
> cooler", aka an "evaporative cooler". Rest assured, they fail to
> violate conservation of energy.
They also fail to work when the relative humidity is 90+%, which was
the situation described in the part of the post that you snipped.
--
Jonathan Guthrie (jgut...@brokersys.com)
Sto pro veritate
David P. Murphy
> We had one when I was a kid, living in the Mojave Desert area.
Lancaster?
ok
dpm
--
David P. Murphy http://www.myths.com/~dpm/
systems programmer ftp://ftp.myths.com
mailto:d...@myths.com (personal)
COGITO ERGO DISCLAMO mailto:Murphy...@emc.com (work)
Rick Dickinson
Murphy) is alleged to have written:
>Rick Dickinson <r...@notesguy.com> wrote:
>
>> We had one when I was a kid, living in the Mojave Desert area.
>
>Lancaster?
Apple Valley. My dad worked for SCE, and got transfered up to Daggett
to work on the Coolwater generating station ("Solar One"). We lived
in Apple Valley for about a year and a half. Our house was 2 blocks
from the Mojave River.
And, bringing this back on-topic, it had a swamp cooler.
- Rick "Great place to be a kid" Dickinson
David P. Murphy
> On Sun, 19 Jan 2003 01:54:01 +0000 (UTC), d...@myths.com (David P.
> Murphy) is alleged to have written:
>>Rick Dickinson <r...@notesguy.com> wrote:
>>> We had one when I was a kid, living in the Mojave Desert area.
>>Lancaster?
> Apple Valley. My dad worked for SCE, and got transfered up to Daggett
> to work on the Coolwater generating station ("Solar One"). We lived
> in Apple Valley for about a year and a half. Our house was 2 blocks
> from the Mojave River.
Antelope Valley, Highland, Lancaster, Littlerock, Quartz Hill,
Palmdale, Victor Valley, Apple Valley. Where were you in '62^78?
jgut...@brokersys.com
> Antelope Valley, Highland, Lancaster, Littlerock, Quartz Hill,
> Palmdale, Victor Valley, Apple Valley. Where were you in '62^78?
I spent three days in Tehachapi toward the end of 1964.
Mike Andrews
> David P. Murphy <d...@myths.com> wrote:
> > Antelope Valley, Highland, Lancaster, Littlerock, Quartz Hill,
> > Palmdale, Victor Valley, Apple Valley. Where were you in '62^78?
> I spent three days in Tehachapi toward the end of 1964.
That's one of the shortest sentences I've ever heard of.
--
... I think the only way a true sysadmin can drag himself into work day
after day is if he really believes, to the bottom of his black little
heart, that It Can't Possibly Get Any Worse. ... you meant something
rather different by "optimist"? -- J. D. Baldwin, in the Monastery
jgut...@brokersys.com
> jgut...@brokersys.com wrote:
>> David P. Murphy <d...@myths.com> wrote:
>> > Antelope Valley, Highland, Lancaster, Littlerock, Quartz Hill,
>> > Palmdale, Victor Valley, Apple Valley. Where were you in '62^78?
>> I spent three days in Tehachapi toward the end of 1964.
> That's one of the shortest sentences I've ever heard of.
Actually, it was the end of a 42-week sentence prior to relocation to
Houston.
Arvid Grøtting
> Oh, higher than expected voltage stories time is it?
I guess I've already told my (230V~ > 0V, wire cutters, wrong fusing)
story, so I'll pass.
--
In its experience the Court has found testimonial predictions of
future events generally less reliable even than testimony as to
historical fact, and cross-examination to be of little use in
enhancing or detracting from their accuracy. -- T. P. Jackson
James Doc Livingston
To add another story to the collection, here's one of mine:
About 5 years ago, in my year 10 science class which was currently
studing electricity, we were playing around with rather some simple
circuits.
One of the pieces of equipment was playing up, and me being one of the
few people (including my teacher, and the lab tech) that actually knew
much about electionic, realised that there was probably something
going on with the line voltage. I went into the storeroom, and grabbed
a voltmeter, a dodgy old analog one. Little did I know that this was a
home-built one that was actually a ammeter, with a display that had a
V on it. I also search for some test lead, and grabbed the closest
ones, which happened to be rated fairly high.
To test the voltage, I plugged the voltmeter(ammeter) into the wall
socket, and switched on. The current surged through the meter, fusing
pretty much everything inside, and blowing the circuit breakers in the
while building.
The moral of this story? Don't assume that a meter with a V on the
panel is a voltmeter...
James "Doc" Livingston
j...@utas.edu.au
Maarten Wiltink
>jgut...@brokersys.com wrote:
>> David P. Murphy <d...@myths.com> wrote:
>> > Antelope Valley, Highland, Lancaster, Littlerock, Quartz Hill,
>> > Palmdale, Victor Valley, Apple Valley. Where were you in '62^78?
>
>> I spent three days in Tehachapi toward the end of 1964.
>
>That's one of the shortest sentences I've ever heard of.
"Jonathan wept."
Tebrgwrf,
Maarten Wiltink
John R. Owens
"No."
--
John R. Owens http://www.ghiapet.homeip.net/
I tried. I tried to warn them. But it all happened, just the way I
remembered.
--Commander Jeffrey David Sinclair
jgut...@brokersys.com
What you're missing is the fact that just about the only thing Tehachapi
is known for is the prison that is located there.
jeff shultz
>Maarten Wiltink <maa...@kittensandcats.net> wrote:
>> Mike Andrews wrote in message ...
>>>jgut...@brokersys.com wrote:
>
>>>> I spent three days in Tehachapi toward the end of 1964.
>
>>>That's one of the shortest sentences I've ever heard of.
>
>> "Jonathan wept."
>
>What you're missing is the fact that just about the only thing Tehachapi
>is known for is the prison that is located there.
You must not be a railfan - the Tehachapi Loop is a rather famous
feature in railroading - where else can you get a photo of a train
looping over or under itself?
Berry Kercheval
> What you're missing is the fact that just about the only thing Tehachapi
> is known for is the prison that is located there.
Railfen know Tehachapi for the "Tehachapi Loop".
http://aeve.com/digitaldesert/tehachapi-loop/
http://www.trainorders.com/cameras/tehachapi/ (live webcam)
jgut...@brokersys.com
> jgut...@brokersys.com writes:
>> What you're missing is the fact that just about the only thing Tehachapi
>> is known for is the prison that is located there.
> Railfen know Tehachapi for the "Tehachapi Loop".
Really? That place is THERE? All I know about it is a few feet of
8mm movie film.
> http://aeve.com/digitaldesert/tehachapi-loop/
> http://www.trainorders.com/cameras/tehachapi/ (live webcam)
My grandfather was WAY into trains and my father once filmed a train
on the loop. Unfortunately, said train was too short so it wasn't
as impressive as it might have been.
Myself, I was taken away after the three days was up and I've never
been back.
Rik Steenwinkel
shultz) persuaded newsservers all over the world to carry the following:
} You must not be a railfan - the Tehachapi Loop is a rather famous
} feature in railroading - where else can you get a photo of a train
} looping over or under itself?
Switzerland.
--
// Rik Steenwinkel # VMS mercenary # Enschede, Netherlands
// 1024D/CDBAE5C1
mic...@news.diaspora.gen.nz
jeff shultz <je...@shultzinfosystems.com> wrote:
>You must not be a railfan - the Tehachapi Loop is a rather famous
>feature in railroading - where else can you get a photo of a train
>looping over or under itself?
Raurimu Spiral, New Zealand.
Richard Bos
The Alps, probably Northern India or even Nepal - anywhere you have
large(ish) mountains and lots of rail, basically. It's hardly a unique
idea. May have been when it was built, but it isn't any more.
Richard
Kenneth Brody
[...]
> But what puzzled me was the air conditioner. It was a *free-standing
> unit*, about six feet tall by two feet by two feet or so, that could
> easily be carried into a room and plugged in. A vent at the top of the
> unit blew air over a whole lot of cooling fins, and the rest of the unit
> was sealed. I couldn't figure out where in the world the heat was
> supposed to go. I don't think the unit was actually attached to anything
> except its power cord: I remember nudging it to see if it was bolted
> down, and it could slide across the floor freely. And I also remember
> checking behind the unit to see if I could feel hot air behind it, and
> not feeling any. As far as I could tell, the thing *should not have
> worked*. But it unquestionably did.
You forgot to look _inside_ the unit, where you would have seen a fan
and a large block of dry ice.
:-)
--
Kenneth Brody http://www.fileproplus.com http://www.hvcomputer.com
filePro: Celebrating 25 years of providing powerful cross-platform
application development tools
jeff shultz
You know, it would be interesting to know if anyone has ever tried to
find all the places where this exists, and gone and photographed them.
That would make one heck of a story for Trains magazine.
Brad Keefer
> Shalom Septimus <drug...@p0b0x.c0m> wrote:
> > On 15 Jan 2003 23:57:44 GMT, st...@madcelt.org wrote:
> >
> >>> Double Phark. Whip out the multimeter, and check the wall wart output.
> >>> Hmm, a tad high[2].
> >>> [2] FSVO 'tad high' nearing 120v
> >
> >>Similar story that happened to me recently:
> >
> > Oh, higher than expected voltage stories time is it?
>
>
My variant of an HTEV story actually involves a cow-orker at $job-1.
'orker was taking a little Ultra 10 down to server room to test if he
could build it with a whzcfgneg server, but he couldn't find an outlet
in a handy location to allow him to plug the Ultra into the network. So
being the bright (l)user he was, he decided to use one of the power
cords from one of the server racks. He plugged in the 10, flipped the
switch on the PS, and was rewarded for his brilliance by a loud pop and
some smoke coming out of the 10. Seems he momentarilly forgot that the
racks were providing 220 current, not 110, like the 10 was expecting b/c
cow-orker forgot to toggle the little red switch to tell it "hey, expect
more current".
--
Brad Keefer -- Unix Geek
joel...@hotmail.com
Chris Suslowicz
je...@shultzinfosystems.com (jeff shultz) wrote:
> You must not be a railfan - the Tehachapi Loop is a rather famous
> feature in railroading - where else can you get a photo of a train
> looping over or under itself?
Ffestiniog?
IGMC
Chris
--
if you continue in your misguided attempt to introduce logic
and reason into a Usenet discussion, men in sunglasses and
black suits will be forced to land their silenced helicopter
on your lawn and explain to you the error of your ways.
:)
Chris Suslowicz
Paul Martin <p...@zetnet.net> wrote:
> In article <3e2d98cb....@news.wvi.com>,
> jeff shultz wrote:
>
> [Railway spirals]
>
> > You know, it would be interesting to know if anyone has ever tried to
> > find all the places where this exists, and gone and photographed them.
> > That would make one heck of a story for Trains magazine.
>
> There's one in the UK on the Ffestiniog railway at Dduallt. The
> original route of the railway was taken for the pumped water storage
> electricity generating plant, and a new route had to be made higher up
> the slope.
>
> http://www.streetmap.co.uk/streetmap.dll?G2M?X=267830&Y=342095&A=Y&Z=3
<Grin> And the CEGB[1] had to pay for the construction of the new line. It
seems they had flooded the place while the railway was "disused", and
not noticed that "Railways are established by Act of Parliament", so even
though there was no track left when they flooded it, it was still a
railway. When the preservation society started rebuilding the line, to
restore it to its original run, the CEGB had to pay for the tunnel and spiral
(etc.) to replace the flooded part.
The Ffestiniog Pumped Storage System[3] at Dinorwig.[4]
Chris.
[1] Central Electricity Generating Board. [2]
[2] Probably nPower, these days.
[3] Since sold to the French.
[4] I still think Dynamo Dinorwig would make a fine name for a football team.
Matthew Skala
I met this guy at a pagan gathering who said he wanted to build a Kirlian
camera (it takes photos of auras or of corona discharges depending on what
you believe; pretty and fun either way), but he had trouble finding the
requisite parts. "Hey, anyone know where I can get a 4000-volt, 0.4-amp
neon sign transformer?"
And I said, "Uh, that's a fair bit of electricity. Are you sure you
didn't miss a decimal point or something?"
And he said, "Oh, 4000 volts isn't really that much."
Unfortunately, I really *don't* know where one could find a transformer
that size cheaply; certainly not on any ordinary neon sign. Maybe two
microwave oven transformers in series. If it were one transformer you
might have a hard time powering it from a single 15-amp 120-volt circuit
anyway, so maybe two microwave oven transformers in series and plugged
into different circuits would really be the best solution. I guess I'll
have to keep my eyes open for a source. Because I am *really* tempted to
present him with what he asked for and watch the fun. As soon as my
liability insurance is paid up.
(Kirlian cameras more commonly use 4000 volts and 5 to 25 milliamps, which
is more than enough to make careful safety procedures a must, especially
when photographing the auras of live humans who wish to remain so.)
--
Matthew Skala, CS PhD student, University of Waterloo
msk...@math.uwaterloo.ca <-- school
msk...@ansuz.sooke.bc.ca <-- home
http://ansuz.sooke.bc.ca/ http://www.edifyingfellowship.org/
John R. Owens
> In article <5pcg2vsirsfr93c8j...@news-50.giganews.com>,
> Shalom Septimus <drug...@pobox.com> wrote:
>>Oh, higher than expected voltage stories time is it?
>
> I met this guy at a pagan gathering who said he wanted to build a Kirlian
> camera (it takes photos of auras or of corona discharges depending on what
> you believe; pretty and fun either way), but he had trouble finding the
> requisite parts. "Hey, anyone know where I can get a 4000-volt, 0.4-amp
> neon sign transformer?"
4000V * 0.4A = 1600W [0]
<snip>
> Unfortunately, I really *don't* know where one could find a transformer
> that size cheaply; certainly not on any ordinary neon sign. Maybe two
> microwave oven transformers in series. If it were one transformer you
> might have a hard time powering it from a single 15-amp 120-volt circuit
120V * 15A = 1800W
So, where's the problem here? Sure, the occasional momentary surge might
trip the circuit breaker, but it's not something that's going to have
devastating results if power is temporarily lost.
> anyway, so maybe two microwave oven transformers in series and plugged
> into different circuits would really be the best solution.
In series, plugged in to different circuits? Are you sure you're the one
who should be offering him advice/help in this matter?
[0] VA if you want to get pedantic, but they convert to Watts.
--
John R. Owens http://www.ghiapet.homeip.net/
Ivanova is always right. I will listen to Ivanova. I will not ignore
Ivanova's reccomendations. Ivanova is God. *And*, if this ever happens
again, Ivanova will personally rip your lungs out!
--Lt. Commander Susan Ivanova
Satya
> 'orker was taking a little Ultra 10 down to server room to test if he
Is it okay to anthropomorphise computers? Because I can just picture an
Igor-style orker leading a scared little (R2D2-type -- no, the other
boxy robot, not the li'l red R5, the other one -- no, to the left!)
Ultra 10 down into a dimly lit basement (ref. Jabba's bot torture room,
without the screams, and the lights are electric, not fire).
> could build it with a whzcfgneg server, but he couldn't find an outlet
> in a handy location to allow him to plug the Ultra into the network. So
So the Ultra stands around, whimpering to itself and looking around in a
scared "ohshitohshitwhereamiwhatshappening" kind of way, while your
orker rummages behind unidentified scrapheap....
> being the bright (l)user he was, he decided to use one of the power
> cords from one of the server racks. He plugged in the 10, flipped the
Ultra goes rigid, emits R2D2-type "AIIIIIIIIIIIIIEEEEEEEEEEEEEEEEEE!
I've been shot by Jawas" bleet, and then emits magic smoke while slowly
toppling to the ground.
I need to get out more.
--
Satya.
Matthew Skala
> So, where's the problem here? Sure, the occasional momentary surge might
One problem is that the transformer probably doesn't operate at 100%
efficiency. I think 90% is typical, which would put him very close to 15
amps. If it's 95%, there's a little more breathing room. Yes, if he goes
over, no big deal, he blows the breaker. The bigger issue is simply that
the output is a non-trivial amount of power, at high enough voltage to
be a problem even through insulation that was designed for lower voltages.
15 amps is a fair bit of current, too, so I hope his plug, wire from the
plug to the infernal device, on/off switch, internal wiring, etc., are all
up to carrying it.
> In series, plugged in to different circuits? Are you sure you're the one
>who should be offering him advice/help in this matter?
Primaries of the two transformers plugged into different 120V circuits,
preferably on opposite sides of the 240V feed into the house.
Secondaries in series. A switch to change the phasing on one of the
transformers to correct for which random circuits you felt like plugging
it into that day. I *don't* advise doing it, but the reason is that the
output voltage and current are inherently dangerous; the scheme I
described is as safe a way of attaining that output voltage and current,
as any.
Chris Suslowicz
msk...@softbase.math.uwaterloo.ca (Matthew Skala) wrote:
> Primaries of the two transformers plugged into different 120V circuits,
> preferably on opposite sides of the 240V feed into the house.
> Secondaries in series. A switch to change the phasing on one of the
> transformers to correct for which random circuits you felt like plugging
> it into that day. I *don't* advise doing it, but the reason is that the
> output voltage and current are inherently dangerous; the scheme I
> described is as safe a way of attaining that output voltage and current,
> as any.
The most dangerous thing in the world: a programmer with a screwdriver.
I don't want to watch, not even from another continent. What you're
suggesting is more suitable for an industrial CO2 laser or _immense_
Tesla coil than anything to be operated within several feet of people.
Chris.
--
"People in general are not fundamentally stupid."
"Cite?"
Robin Munn & Simon Cozens in the scary devil monastery
David P. Murphy
> I don't want to watch, not even from another continent. What you're
> suggesting is more suitable for an industrial CO2 laser or _immense_
> Tesla coil than anything to be operated within several feet of people.
http://espn.go.com/page2/s/tmq/030114.html
search for "space mirror".
david parsons
Paul Martin <p...@zetnet.net> wrote:
>In article <3e2d98cb....@news.wvi.com>,
> jeff shultz wrote:
>
>[Railway spirals]
>
>> find all the places where this exists, and gone and photographed them.
>> That would make one heck of a story for Trains magazine.
>
Does the Ffestiniog even have enough rolling stock to have a train
loop over itself there? The other reason[1] the Tehachapi loop is
famous is because the railways that own it regularly run very long
trains over it -- the loop is fairly tight (a little under 4000 feet
if the railfan websites are to be believed) so being able to take a
picture of the locomotives passing over or under the rear of the
train is fairly commonplace.
[1 The first reason, of course, is because it's in the United States;
the typical american railfan isn't particularly interested in railways
elsewhere in the world.]
____
david parsons \bi/ We're kind of insular that way.
\/
Earl Grey
> The most dangerous thing in the world: a programmer with a screwdriver.
So you did some work with CrossTalk too, yeah?
" Beware of programmers with screwdrivers.
Nowadays, it's:
" Beware of SysAdmins with Leathermen.
Bogdan Iamandei [ROT13]
Yes - it is fear, but it's not the *same* fear.
Ino!~
--
I have seen things you people wouldn't believe. Attack ships on fire
off the shoulder of Orion. I watched C-beams glitter in the dark
near the Tannhauser Gate. All those moments will be lost in time,
like tears in rain. Time to die.
Will Salt
> In article <slrnb2r9...@laptop.nowster.org.uk>,
> Paul Martin <p...@zetnet.net> wrote:
> >
> > There's one in the UK on the Ffestiniog railway at Dduallt. The
> > original route of the railway was taken for the pumped water storage
> > electricity generating plant, and a new route had to be made higher up
> > the slope.
> >
> <Grin> And the CEGB[1] had to pay for the construction of the new line. It
> seems they had flooded the place while the railway was "disused", and
> not noticed that "Railways are established by Act of Parliament", so even
> though there was no track left when they flooded it, it was still a
> railway.
The Ffestiniog was unusual in this regard because it was a very early
railway - pre-Victorian, in fact. Railways built, say, 10 years
later all had "Abandonment clauses" written into their Acts, stating
what would happen if the company was unable to operate the line. The
drafters of the Ffestiniog's bill didn't think of that, so when the
company couldn't afford to run trains any more all it could do was
leave the line to rot. When the CEGB started work (about 10 years
later) the railway's track was still there, because it couldn't
legally be scrapped.
Back to the original point: the unusual thing about the Tehachapi loop
is that a lot of the trains that use it are longer than the loop
itself, so you can see part of the train passing over a bridge at the
same time as another part of the train is going underneath it. At
other spirals, such as Dduallt[0], this is very unlikely to happen.
[0] If you don't understand Welsh pronunciation: a former General
Manager of the Ffestiniog said that Dduallt is "best pronounced by
sneezing". This isn't too far off.
[1] NMF
--
Will Salt
Alan J. Wylie
> The Ffestiniog Pumped Storage System[3] at Dinorwig.[4]
Dinorwi{c,g}[5] is just north of Llanberis, Ffestiniog is about 15 miles
south-east of there. Dinorwig is a truly impressive facility. See
http://groups.google.com/groups?selm=3740D45C.42D6720%40freeuk.com
or google for Dinorwi{c,g} and Turbines.
It's just round the corner from a mountaineering club hut I help
maintain[6], but, as is always the way, I've never got round to taking
the _Magic Mountain_ tour.
> [3] Since sold to the French.
> [4] I still think Dynamo Dinorwig would make a fine name for a football team.
[5] My O.S. Motoring Atlas of Britain spells it Dinorwig, my
O.S. 1:25,000 map of Snowdonia spells it Dinorwic.
[6] http://www.karabiner.org/hut/
--
Alan J. Wylie http://www.glaramara.freeserve.co.uk/
I'm looking for a job. CV at http://www.glaramara.freeserve.co.uk/cv.html
Unix/Linux/C/Internet/embedded and lots more. UK:Bradford/Manchester
Greg Andrews
>On Tue, 21 Jan 2003, Chris Suslowicz wrote:
>
>> The most dangerous thing in the world: a programmer with a screwdriver.
>
>So you did some work with CrossTalk too, yeah?
>
>Beware of programmers with screwdrivers.
s/with/who carry/
I worked for Crosstalk in 1988, just about the time the
programmers had to shut off the "message of the day" that
Crosstalk XVI displayed on the splash screen. Too many
morons were calling tech support afraid they had a virus
on their computer.
-Greg
--
::::::::::::::: Greg Andrews :::::: ge...@panix.com :::::::::::::::
Hardware, n.: The parts of a computer system that can be kicked.
Garrett Wollman
Lionel <n...@alt.net> wrote:
>Just don't ask me to explain about power factors, as I'm pretty hazy on
>the theory involved.
I don't recall that as being all that difficult; it's just the ratio
of the two. (What's the name for the quantity that is measured in VA,
anyway? I'm drawing a total blank.)
Think for a moment about what a volt-ampere actually is: it's
$V_{rms}$ times $I_{rms}$, so it doesn't actually take into account
the phase difference between voltage and current in reactive circuits,
as we have been discussing. If you actually do the integration you
come up with average power $P = {{VI}\over 2}\cos\phi$, where $\phi$
is the phase angle[1] at which voltage leads current. The value
$\cos\phi$ is the power factor. The quantity ${VI}\over 2$ is
trivially equal to $V_{rms}I_{rms}$ which is that quantity I can't
remember the name of.
Not a great deal of theory involved; I just looked it up on my
12-year-old intro physics textbook.
Of course we care about this because the power supply and wiring must
be sized to supply the required peak current independent of the
voltage, even if the average power (integrated over a long period of
time, like a monthly billing cycle) is very small. (Recall that a
pure capacitive or inductive load would have average power of zero.)
The power factor quantifies this difference between demand and load
with a simple metric.
-GAWollman
[1] $\cos\phi$ can never be negative for reasons of physical law, so
the phase angle $\phi$ is always in the first or fourth quadrant.
--
Garrett A. Wollman | [G]enes make enzymes, and enzymes control the rates of
wol...@lcs.mit.edu | chemical processes. Genes do not make ``novelty-
Opinions not those of| seeking'' or any other complex and overt behavior.
MIT, LCS, CRS, or NSA| - Stephen Jay Gould (1941-2002)
Kevin Goebel
Suslowicz) wrote:
>> Primaries of the two transformers plugged into different 120V circuits,
>> preferably on opposite sides of the 240V feed into the house.
>> Secondaries in series. A switch to change the phasing on one of the
>> transformers to
>The most dangerous thing in the world: a programmer with a screwdriver.
>I don't want to watch, not even from another continent. What you're
>suggesting is more suitable for an industrial CO2 laser or _immense_
>Tesla coil than anything to be operated within several feet of people.
Kirlian-Schmirlian... I could care less about photographing someone's boring
aureolas, but industrial strength lasers and Telsa coils - Now you're
talking! Sounds like just the thing for the coat closet at the front door.
If Scientology or LDS annoyances knock on the door, ZAP goes the laser. If
the air raid siren goes off or day-bright light starts streaming under the
door sill at midnight, make a Telsa connection to the tinfoil lining the
inside walls!
"Send a charge through the hull, Lee!" (c) Voyage to the Bottom of the Sea
Kevin
Satya
> aureolas, but industrial strength lasers and Telsa coils - Now you're
> door sill at midnight, make a Telsa connection to the tinfoil lining the
> inside walls!
Telsa? Tesla? Now you've confused me.
You have to be careful, you could set fire to the habitat. Use only in
case of giant squid attack.
--
Satya.
A confused person is a defused person.
joe
je...@shultzinfosystems.com wrote on 1/21/03 11:39 AM:
> On Mon, 20 Jan 2003 17:56:37 -0600, jgut...@brokersys.com wrote:
>
>> Maarten Wiltink <maa...@kittensandcats.net> wrote:
>>> Mike Andrews wrote in message ...
>>>> jgut...@brokersys.com wrote:
>>
>>>>> I spent three days in Tehachapi toward the end of 1964.
>>
>>>> That's one of the shortest sentences I've ever heard of.
>>
>>> "Jonathan wept."
>>
>> What you're missing is the fact that just about the only thing Tehachapi
>> is known for is the prison that is located there.
>
> You must not be a railfan - the Tehachapi Loop is a rather famous
> feature in railroading - where else can you get a photo of a train
> looping over or under itself?
Somewhere on the Moebius line, perhaps?
Joe Zeff
com> wrote:
>I could care less about photographing someone's boring
>aureolas
I, OTOH,find aureoles quite interesting, provided the person's of the
appropriate gender. Auras, now, that's something I find hard to care
about.
--
Joe Zeff
The Guy With the Sideburns
If you can't play with words, what good are they?
http://www.lasfs.org http://home.earthlink.net/~sidebrnz
Alan J Rosenthal
>Is it okay to anthropomorphise computers?
ObSetup: No. They hate it when you do.
Shmuel (Seymour J.) Metz
at 01:00 AM, Joe Zeff <the.guy.with....@lasfs.org> said:
>I, OTOH,find aureoles quite interesting, provided the person's of the
>appropriate gender.
And not too garstly.
--
Shmuel (Seymour J.) Metz, SysProg and JOAT
Reply to domain Patriot dot net user shmuel+bspfh to contact me.
They don't really have flames on Usenet. They think they do,
but that's only because they've never seen the real thing.
Satya
Changi airport is wondering why I'm falling off my chair.
Okay, so I didn't actually laugh, I just wanted to name-drop. And
mention that using a J*va client to ssh across 2 boxen and 2 continents
is uber-cool, or would be if the keyboard didn't suck and I wasn't
slightly paranoid about key-sniffing[0] programs.
[0] I meant keystroke-sniffing, of course.
--
Satya.
Alan J Rosenthal
...
>slightly paranoid about key-sniffing[0] programs.
>
>[0] I meant keystroke-sniffing, of course.
Good thing you cleared that up. I thought that there was some relative of the
key-slapping slizzard we now had to deal with.
(In addition to MS SQL worms that is.)