Driving 1,000 computer monitors?

[Phil Allison]

"Roger Lascelles" <

"FruitLoop" <Hyperactive@fruitloop.net


** The excess neutral current will be a major problem.


Thats bullshit , if the 3 phase load is close to balanced then the
neutral
technically can be floating .

Phil's post seems valid to me.

This article mentions the non-balanced neutral problem.

http://www.jmwa.demon.co.uk/EMCLF0010.htm

3 phase balancing works when the loads draw sinusoidal current. Computer
monitors have bridge rectifiers across the mains input, which charge
capacitors with short pulses of current near the peaks of the sinewave. So
the phases see large amplitude, narrow current pulses - at 120 degree
timing
with little neutral cancellation - so the neutral wire is working very
hard.

** In any case, the only time the neutral can be left floating in when the
3 phase load is ONE device.

Where multiple, single phase devices constitute the total load, each with
thier own switches, fuses etc it is utterly out of the question.




........... Phil

 

[Moses Lim]

Terry Collins wrote:

How?

Actually, what jargon should I use to search for circuits to build.


The background is that I do work for a community group that re-uses old
computers and we currently have premises in an arts centre. Our "rent"
is basically technical knowledge and assistance to support vqarious
"artistic" projects.

Apologies for the unorthodox method of approaching the subject, but I think
I have met you in the company of Dan, Grant, Mark, et al.

If you are who I think you are, would it be possible to get one of them to
contact me, pls? Perhaps, Grant or Mark? Pls note that I have emailed them
using a new email address.

Thanks.

 

[Moses Lim]

Terry Collins wrote:

John Mackesy wrote:
Our
"rent" is basically technical knowledge and assistance to support
vqarious "artistic" projects.

I've seen something like this using TV sets? video monitors? at a
shopping centre, only they formed 1 *BIG* picture. I'd suggest it'd be
cheaper/easier to use TV's and you'd get the same result.

Umm, this is "art", you know, here today, gone tomorrow, faster than a
movie set. so, there is no/absolute minimal budget. (hmm, anyone know of
a movie set that needs something like this).

You never know in a big city like Syd-na-nee Know a guy who built a 24:1
pulley system for special fx - gun shots, falling off bikes, etc

 

[FruitLoop]

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:3n0leqF18ll21U1@individual.net...

"Roger Lascelles"

"FruitLoop" <Hyperactive@fruitloop.net


** The excess neutral current will be a major problem.


Thats bullshit , if the 3 phase load is close to balanced then the
neutral
technically can be floating .

Phil's post seems valid to me.

This article mentions the non-balanced neutral problem.

http://www.jmwa.demon.co.uk/EMCLF0010.htm

3 phase balancing works when the loads draw sinusoidal current.
Computer
monitors have bridge rectifiers across the mains input, which charge
capacitors with short pulses of current near the peaks of the sinewave.
So
the phases see large amplitude, narrow current pulses - at 120 degree
timing
with little neutral cancellation - so the neutral wire is working very
hard.



** In any case, the only time the neutral can be left floating in when
the
3 phase load is ONE device.

Where multiple, single phase devices constitute the total load, each with
thier own switches, fuses etc it is utterly out of the question.




.......... Phil

Phillis , try it yourself get a 3 phase load , all independant , roughly
balanced ( like me ) and then connect all the neutrals to create a star
point , but dont connect to a neutral . It WILL work .

 

[Michael C]

"Terry Collins" <terryc.bling@woa.com.au> wrote in message
news:430927f3$0$55616$c30e37c6@ken-reader.news.telstra.net...

This one comes out a project that will be a wall of computer monitors
(db15 plug driven) all showing the same image, so my understanding says
that we are going to need an amplifier and splitters or
splitter-amplifier, preferrably with the least number of stages.

Hence, my question for assistance in what jargon I should plug into search
engines.

This is basically for the mathematics of costing the construction of the
video splitters, etc.

This question is really obvious which is probably why no one has asked it,
but why not LCDs? The extra expense might be saved on what sounds like
expensive power considerations and scaffolding.


Michael

 

[Phil Allison]

"FruitLoop" = brain dead fucking maggot

Phillis , try it yourself get a 3 phase load , all independant , roughly
balanced ( like me ) and then connect all the neutrals to create a star
point , but dont connect to a neutral . It WILL work .

** You go do it - you stinking, asinine fuckhead.

But instead of a motor or three room heaters, use 3 TV sets.

Then learn how to read.




.......... Phil

 

[Phil Allison]

"Michael C" ...

"Terry Collins"

This question is really obvious which is probably why no one has asked it,
but why not LCDs?

** Because he already has 1000 CRT monitors - old, discarded ones.

Read the damn thread.



........... Phil

 

[Richard Freeman]

"FruitLoop" <Hyperactive@fruitloop.net> wrote in message
news:m96Pe.9303$FA3.6664@news-server.bigpond.net.au...

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:3n0leqF18ll21U1@individual.net...

"Roger Lascelles"

"FruitLoop" <Hyperactive@fruitloop.net


** The excess neutral current will be a major problem.


Thats bullshit , if the 3 phase load is close to balanced then the
neutral
technically can be floating .

Phil's post seems valid to me.

This article mentions the non-balanced neutral problem.

http://www.jmwa.demon.co.uk/EMCLF0010.htm

3 phase balancing works when the loads draw sinusoidal current.
Computer
monitors have bridge rectifiers across the mains input, which charge
capacitors with short pulses of current near the peaks of the sinewave.
So
the phases see large amplitude, narrow current pulses - at 120 degree
timing
with little neutral cancellation - so the neutral wire is working very
hard.



** In any case, the only time the neutral can be left floating in when
the
3 phase load is ONE device.

Where multiple, single phase devices constitute the total load, each with
thier own switches, fuses etc it is utterly out of the question.




.......... Phil




Phil , try it yourself get a 3 phase load , all independant , roughly
balanced ( like me ) and then connect all the neutrals to create a star
point , but dont connect to a neutral . It WILL work .

A balanced three Phase load is completely irrelevant to the current topic -
that is 1000 Computer monitors being connected to Mains.
I am afraid that Phil and Roger are quite correct Computer monitors do not
draw Sinusoidal current rather they draw short pulses of current near the
peak of each Sine wave.
These Pulses on different phases come nowhere close to cancelling each other
out.

 

[Michael A. Terrell]

Richard Freeman wrote:

A balanced three Phase load is completely irrelevant to the current topic -
that is 1000 Computer monitors being connected to Mains.
I am afraid that Phil and Roger are quite correct Computer monitors do not
draw Sinusoidal current rather they draw short pulses of current near the
peak of each Sine wave.
These Pulses on different phases come nowhere close to cancelling each other
out.

In fact, large numbers of switching power supplies on a three phase
system require a larger neutral than the same system with a purely
resistive load. This is due to all the harmonics generated by the power
supplies that have no power factor correction. A number of fires in
offices and factories occurred when large numbers of switching supplies
were installed, starting about 20 to 25 years ago.

I had a neutral fire in the breaker box for a CATV headend in 1985 due
to all the harmonics caused by the newer equipment we were installing.

--
Link to my "Computers for disabled Veterans" project website deleted
after threats were telephoned to my church.

Michael A. Terrell
Central Florida

 

[FruitLoop]

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:3n4l5sF198pisU1@individual.net...

"FruitLoop" = brain dead fucking maggot

But im a lot richer than you , in many ways , hahahahahaha

Phillis , try it yourself get a 3 phase load , all independant ,
roughly
balanced ( like me ) and then connect all the neutrals to create a star
point , but dont connect to a neutral . It WILL work .



** You go do it - you stinking, asinine fuckhead.

I have in my shed atm , wanna come over and have a look ?

But instead of a motor or three room heaters, use 3 TV sets.

Then learn how to read.

Like you can , dont make me laugh . hahahahahahaha

......... Phil

 

[Michael C]

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:3n4ld5F19b2dlU1@individual.net...

** Because he already has 1000 CRT monitors - old, discarded ones.

Read the damn thread.

Did you miss the bit where I said *extra* expense? Maybe you should read
*my* damn post again.

Michael

 

[Phil Allison]

"Michael C" = the C stands for what ?

"Phil Allison"

** Hey - you sniped the CONTEXT out - arsehole !!!!!

So I am putting it back:

This question is really obvious which is probably why no one has asked it,
but why not LCDs? The extra expense might be saved on what sounds like
expensive power considerations and scaffolding.


** Because he already has 1000 CRT monitors - old, discarded ones.

Read the damn thread.

Did you miss the bit where I said *extra* expense?

** 1000 LCD screens costs what ???

$ 300,000 or so.

The AC power is available and shelving is cheap.

Maybe you should read *my* damn post again.

** No thanks - the sheer fucking stupidity of it made me fell ill the
first time.





............. Phil

 

[Michael C]

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:3n58d8F19lb3fU1@individual.net...

arsehole !!!!!

I think if we took a poll of this group we know who'd be fighting for
biggest arsehole award, although maybe your mate rod speed would just sneak
in.

** 1000 LCD screens costs what ???

$ 300,000 or so.

At RETAIL prices for 17" monitors in quantities of 1. The op wanted 14"
monitors.

** No thanks - the sheer fucking stupidity of it made me fell ill the
first time.

It's "fall ill" stupid.

Michael

 

[Phil Allison]

"Michael C" = C stands for Colossal Cunt

"Phil Allison"

** Hey - you sniped the CONTEXT out AGAIN - arsehole !!!!!

So I am putting it ALL back AGAIN !!!

This question is really obvious which is probably why no one has asked it,
but why not LCDs? The extra expense might be saved on what sounds like
expensive power considerations and scaffolding.


** 1000 LCD screens costs what ???

$ 300,000 or so.

The AC power is available and shelving is cheap.

At RETAIL prices for 17" monitors in quantities of 1. The op wanted 14"
monitors.

** Totally INSANE CRAP !!!

Michael Cunt should have his balls cut off of prevent breeding with the
likes of FruitLoop.






........... Phil

 

[Terry Collins]

Michael C wrote:

** 1000 LCD screens costs what ???

$ 300,000 or so.


At RETAIL prices for 17" monitors in quantities of 1. The op wanted 14"
monitors.

The artist will take anything that he can get for FREE.
We can/will provide 14"& 15" monitors because peeps don't want them.

There is no budget for the purchase of monitors and I strongly suspect
that there will not be a budget for purchase of anything commercial.

 

[quietguy]

Just thought that it is going to take a lot of electric to run all those
monitors - 400 or so amps, 100 kw - lots of nice warm air - and at 20c a kwh
about $20 hr to run them.

Lots of outlay for a non-profit org - apart from all the shelving, wire
etc. Sounds like a fun thing though

David

Terry Collins wrote:

Michael C wrote:

** 1000 LCD screens costs what ???

$ 300,000 or so.


At RETAIL prices for 17" monitors in quantities of 1. The op wanted 14"
monitors.

The artist will take anything that he can get for FREE.
We can/will provide 14"& 15" monitors because peeps don't want them.

There is no budget for the purchase of monitors and I strongly suspect
that there will not be a budget for purchase of anything commercial.

 

[Terry Collins]

quietguy wrote:

Just thought that it is going to take a lot of electric to run all those
monitors - 400 or so amps, 100 kw - lots of nice warm air - and at 20c a kwh
about $20 hr to run them.

Lots of outlay for a non-profit org - apart from all the shelving, wire
etc. Sounds like a fun thing though

Not us. We're just stoked that we might have found a way to shift 1,000
old monitors instead of paying for disposal {.

I'm not holding my breath that this is going to come off in the form
envisaged, but it would be great to see if it did.

I think it will be a lessor form, probably just a couple of hundred
computers. I suspect it will really depend on how many video splitters
can be made/afforded as that seems to be the expensive part.

Thanks to everyone for comments.

 

[Phil Allison]

"Michael C" = usenet troll and anencephalic


** That " C " stands for Cock Sucker.







.......... Phil

 

[Michael C]

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:3n7h7bF7he8U1@individual.net...

"Phil Allison"

** Hey - you sniped the CONTEXT out AGAIN - arsehole !!!!!

So I am putting it ALL back AGAIN !!!

I snipped your usual useless blabbering.

"Michael C" = C stands for Colossal Cunt

How old are you? This really is something a 7 year old would come up with.

BTW, you didn't actually answer my post, just threw insults. I'll take that
as an admission of defeat.

Michael

 

[Michael C]

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:3ni614F1je00U1@individual.net...

"Michael C" = usenet troll and anencephalic


** That " C " stands for Cock Sucker.

Fark phil, I'd forgotten about your dumb arse for days and you replied
within 1 minute. What are you doing, sitting here pushing the refresh button
over and over?

Michael