What is VA...ref. transformers

[chas]

Checkiing to buy a transformer, I see most of them don't publish the output
amps but do give a stat 'VA'. Is this just wattage?. .. .chas

[Phil Allison]

"chas"

>
> Checkiing to buy a transformer, I see most of them don't publish the
> output amps but do give a stat 'VA'. Is this just wattage?.

** Generally no.

VA and watts are the same only if the load is resistive, like incandescent
lamps.

By using VA , the makers are letting you know that a transformer can deliver
a certain load current in RMS amps and no more.

It is possible for the watts actually delivered to the load to be zero, if
the load is a pure capacitance or inductance, and the tranny is still
operating at its max safe current.



.... Phil

[Larry]

"chas" wrote in message news:X3mks.20397$c16....@newsfe10.iad...

Checkiing to buy a transformer, I see most of them don't publish the output
amps but do give a stat 'VA'. Is this just wattage?. .. .chas

***

Volt Amp
http://lmgtfy.com/?q=volt+amp

[Tim Wescott]

On Wed, 31 Oct 2012 21:27:21 -0600, chas wrote:

> Checkiing to buy a transformer, I see most of them don't publish the
> output amps but do give a stat 'VA'. Is this just wattage?. .. .chas

The transformer doesn't care what power is traveling through it.

The core cares about the voltage and the frequency.

The windings care about the RMS current.

So the transformer is rated by "VA" -- it's your job to know how much of
that you're going to waste in inefficiencies, and how much you're
actually going to extract from the secondary.

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com

[Phil Allison]

"Tim Wescott"

>
> The transformer doesn't care what power is traveling through it.

** Really ??

I suspect practical examples very much do.



... Phil

[Tim Wescott]

I have yet to see a transformer that's rated for power in addition to
maximum voltage, frequency, and maximum current. So no, I don't see
where it makes a difference to the _transformer_ whether you're getting
no power out of it at rated voltage and current, or if you've managed to
achieve a power factor of 1 and have P = VA.

_Circuit designers_ care what power is going through the transformer,
which is why we pay attention to how much of the current is actually
going to carrying power, why we favor some circuits over others, or at
least why we seemingly over-specify transformers compared to the
specifications of the power supplys that they're in.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

[Phil Allison]

"Tim Wescott"

> Phil Allison wrote:
>
>> "Tim Wescott"
>>
>>
>>> The transformer doesn't care what power is traveling through it.
>>
>>
>> ** Really ??
>>
>> I suspect practical examples very much do.
>
> I have yet to see a transformer that's rated for power in addition to
> maximum voltage, frequency, and maximum current. So no, I don't see
> where it makes a difference to the _transformer_ whether you're getting
> no power out of it at rated voltage and current, or if you've managed to
> achieve a power factor of 1 and have P = VA.

** What a pile of fucking irrelevant crap !!!

Read what you actually wrote - shithead.

It is UTTERLY WRONG.



.... Phil

[Jamie]

Phil, I think you better read it closer yourself, Tim has outwitted you
with that statement.
I know you guys down under have a totally different understanding
mechanism but come on now, is it really that bad?

Jamie

[Phil Allison]

"Jamie" = radio ham moron: Maynard A. Philbrook



** Fuck off and die

- you stinking pile of AUTISTIC septic shit.

[Tim Wescott]

Take your meds.

[Phil Allison]

"Tim Wescott"
>> Phil Allison wrote:
>>
>>> "Tim Wescott"
>>>
>

>> ** What a pile of fucking irrelevant crap !!!
>>
>> Read what you actually wrote - shithead.
>>
>> It is UTTERLY WRONG.
>
> Take your meds.

** That is a REALLY STUPID and fowl remark.

There is NO medication on earth that cures what YOU have - asshole !!

FFS : READ WHAT YOU WROTE !!!!!!!!!!!!!!!!!!!!!!!!!!!

What does it fucking say ???????

-------------------------------------------------

Here it is again - you fucking, posturing TWAT

> Checkiing to buy a transformer, I see most of them don't publish the
> output amps but do give a stat 'VA'. Is this just wattage?. .. .chas

The transformer doesn't care what power is traveling through it.

--------------------------------------------------

** Still got no idea how STUPID it is to say that ???

Transformers can pass infinite amounts of power can they ?????


FFS, dickwad:

1. Learn to write clear English.

2. Learn to READ what others are REALLY asking and saying.

3. Learn to fucking READ what you write yourself for the MOST OBVIOUS
meaning.


Now - fuck off usenet entirely until you can do all three.

I expect to see ya back not earlier than next century.

Shithead.



... Phil

[George Herold]

On Nov 2, 3:53 am, "Phil Allison" <phi...@tpg.com.au> wrote:
>  "Tim Wescott"
>
> >> Phil Allison wrote:
>
> >>> "Tim Wescott"
>
> >>  ** What a pile of fucking irrelevant crap !!!
>
> >>      Read what you actually wrote  -  shithead.
>
> >>      It is  UTTERLY  WRONG.
>
> > Take your meds.
>
> ** That is a  REALLY  STUPID  and fowl remark.
>
> There is  NO medication on earth that cures what  YOU have  -  asshole !!
>
> FFS :   READ  WHAT  YOU  WROTE   !!!!!!!!!!!!!!!!!!!!!!!!!!!
>
> What does it fucking say   ???????
>
> -------------------------------------------------
>
> Here it is again - you  fucking,  posturing  TWAT
>
> > Checkiing to buy a transformer,  I see most of them don't publish the
> > output amps but do give a stat 'VA'.  Is this just wattage?. .. .chas
>
> The transformer doesn't care what power is traveling through it.
>
> --------------------------------------------------
>
> ** Still got no idea how STUPID it is to say that  ???
>
> Transformers can pass infinite amounts of power can they  ?????

Geesh Phil, I guess you can take Tim's line out of context and take it
to mean the above. But I had no trouble understanding what Tim was
saying. (And I'm far from a transformer expert.)

George H.

[Phil Allison]

"George Herold"

I guess you can take Tim's line out of context

** FFS I quoted the **ENTIRE** context !!!

Piss off, idiot.



.... Phil

[Cydrome Leader]

holy smokes. I want to know more about the "fowl remark" you're talking
about, and how it applies to your steps 1, 2 and 3.

[Jim Thompson]

"fowl" is how Phil spells "foul" when he's off his med's... which is
most of the time >:-}

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

[Cydrome Leader]

he seems like a touchy fellow. Anybody know his story?

[Phil Allison]

"Cydrome Leader"


** Why not address the issue instead of trolling ?

Or is the latter ALL you are capable of ?

( Rhetorical questions )

[k...@att.bizzz]

On Mon, 5 Nov 2012 23:35:59 +0000 (UTC), Cydrome Leader

http://history.dircsa.org.au/1800-1899/lunatic-asylum/

Phyllis and Slowman are descendents.

[Michael A. Terrell]

Jim Thompson wrote:
>
> "fowl" is how Phil spells "foul" when he's off his med's... which is
> most of the time >:-}

And he 'fowls' his nest? ;-)

[Michael A. Terrell]

k...@att.bizzz wrote:
>
> http://history.dircsa.org.au/1800-1899/lunatic-asylum/
>
> Phyllis and Slowman are descendents.

True, and they can't go any lower.