Connect a vibrator from an old tube type car radio and with the proper
transformer and circuitry, you can make AC voltage. There was a time
when the word "vibrator" described an integral component of vehicle
mounted tube type electronic equipment. ^_^
On Sunday, December 1, 2013 10:31:09 AM UTC-5, Emma Genius wrote:
Since you're a genius, perhaps you can do what no one else
here except myself has been able to do and that is give
a definition of the electricl engineeing term "phase".
You have 10 people pontificating on it, yet not one of them
can define it. I gave the defintion a week ago.
Suppose you wanted to run an irrigation system that requires three
phase, 480 to operate. Suppose the local rural power company could only
supply you with single phase 480. Suppose Emma Genius then built a
rotary phase converter to make that three phase load run from single
Suppose that rotary phase converter created only the third leg of
the three phase to operate the three phase load. Where did the other
two necessary phases originate to operate that three phase load?
On Monday, December 2, 2013 6:05:15 PM UTC-5, Dean Hoffman wrote:
I'm still waiting for one of the "experts" to give us their
definition of phase. They've been talking about it for a week now,
but not one will define it.
I'm also waiting for a response to the two phase student excercise
I posted earlier. They all seem to agree that two phase existed
100 years ago. They have no problem with it being called two
phase, that was the only legitimat two phase according to them.
So, that system had two phases, let's call them A and B
and a neutral. Phase B was 90 deg off from phase A. Everyone OK
Now, instead of having phase B be off by 90 degrees, let's make it
off by 120 deg. How many phases are there now? I say two. Let's
change it again, so phase B is off by 220 degrees. How many phases
do we have now? I say two. Let's change it to being off by 170 deg,
how many phases do we have now? I say two. And now, let's change
it to be off by 180 deg. How many phases do we have now? I say
two. And if it they agree that it is indeed still two, then it
is in fact electrically identical to split-phase 240/120V service,
so you have two phases there too.
On Monday, December 2, 2013 8:29:20 PM UTC-5, Edwin wrote:
Complete inability to address the simple and carefully outlined learning excercise I gave, noted. Inability to even define the term "phase", as requested noted. As is the name calling which is what you're left with
when you don't have engineering or the facts on your side. And for the
record, a scope wasn't even involved.
On Tuesday, December 3, 2013 5:04:51 AM UTC-5, ralph wrote:
Again, complete avoidance of the intellectual excercise on phase I outlined above noted. No answer to the simple question of giving a definition of the engineering term "phase" noted. Smart remarks don't build a case.
I can define it. And I'm still waiting for an answer why a system with
two phases that differ by 90 deg is acknowledged by everyone to have two
phases. If they differ by 240 deg, that's two phase right? If they
differ by 170 deg, that must be two phases, right? So, what magically
happens when they differ by 180 deg that suddenly there are no longer two
phases? And how do the electrons know?
On Tuesday, December 3, 2013 12:07:05 PM UTC-5, bud-- wrote:
Non-response to the simple thought excercise on phase, going from
what everyone agrees is two phase, to what is electrically identical
to the 240/120V split-phase service.
Non-response to repeated requests for anyone on the other side of
this to define the term "phase". How can you talk about it, yet
not one of you can define it?
As to your question, IDK why you're asking. My answer is clear
and has been discused at length. The answer is Yes. The author
of the engineering paper presented at the IEEE conference of power
engineers agrees. As do the several white papers/app notes from
electrical eqpt manufacturers, etc. that I've cited as well.
On 12/3/2013 11:27 AM, firstname.lastname@example.org wrote:
As previously posted, in the second half of the abstract the author
suggests a _change_ from the standard practice and wants to call
split-phase 2 phase. No vote on his suggestion is recorded. In the first
half the author says the standard practice is to call split-phase
The abstract does not agree with you.
In maths/physics, you have two phases with a mathematical
relationship of -x (or a 180 deg phase shift).
In electrical distribution, two-phase is a specific jargon term
which means something else.
There's no one right answer - it depends on the context of the
[email address is not usable -- followup in the newsgroup]
The context is, specifically, in US power distribution is a split-phase
supply called 2 phase with a phase A and phase B.
(Not "2-phase", which as you say is rather different.)
I don't think you have much split-phase over the pond. If I remember
right, construction sites may have 120/60V circuits.
No. 240/480V was only used on farms in very remote areas,
and there were probably no new installations of this type
since WWII (and there maybe none left by now, having all
been upgraded to 3-phase).
It's not necessary elsewhere here because we run 230V 3-phase
down each street, so houses which need more than 1 phase get
a 3-phase 230/400V supply. (In reality, it's 240/415V for
That doesn't work with the US 120/240V, because, to a first
approximation, you can only carry it a quarter of the distance
before the voltage regulation goes too bad (and the low power
pole mount transformers actually make this much worse).
This means you have to carry the high voltage supply down
each street and use regularly spaced pole transformers to
generate the 120/240V supplies. To keep costs down, there's
usually only 1 of the 3 phases from the HV supply carried
down each street, so you don't generally have access to a
3-phase supply in any one residential street.
Construction sites here use a safety supply of 110V with
earthed centre-tap, i.e. 55-0-55 for single phase and 65/110V
for 3-phase, but the 0V connection is only grounded at the
transformer and carried to tools as a protective ground
conductor, and never used as a power conductor, so these
are never described as 55-0-55 or 65/110V supplies, because
there's no neutral connection. This is designed to prevent
electrocution of construction workers if a tool gets dropped
into a puddle or the cord is damaged or something similar,
as the highest voltage to ground is only 55 or 65V.
This safety supply used to be mandatory on UK construction
sites. It's no longer mandatory (that would be contrary to
EU rules on movement of workers and products), but it's what
you'll still find on all UK construction sites.
[email address is not usable -- followup in the newsgroup]
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