Re: Mains transformer weights

"Jim Hawkins" <(E-Mail Removed)> wrote in
news:(E-Mail Removed) m:

> Jim Hawkins wrote:
>> Is a mains transformer designed for 60Hz significantly lighter than
>> one of the same VA rating designed for 50Hz ?
>>
>> Jim Hawkins
>
> Following on from this, why is it that electricity generation is
> limited to such low frequencies as 50 or 60 Hz ?
> As the frequency rises, the energy lost through electromagnetic
> radiation from the wires rises, but is it really a significant amount
> ? Would it be significant at 1 kHz ? If not, why isn't generation
> done at that sort of frequency ? The savings in transformer weights
> and sizes everywhere would be enormous. Is it because of mechanical
> engineering limitations on the rotational speeds of the large rotary
> generators the power stations use ?
>
>
>

I have worked in the airforce, they also used 400 Hz
on(or under) the ground.
You could hear the 3rth harmonic(1200 Hz) all over the
place, wich is not such a good idea in your home.
Very iritating for new workers, old workers had a
measurable dip in their hearing curve, and could not
hear that frequency anymore.Permanent damage.

Sjouke Burry <s@b> wrote:
> "Jim Hawkins" <(E-Mail Removed)> wrote in
> news:(E-Mail Removed) m:
>
>> Jim Hawkins wrote:
>>> Is a mains transformer designed for 60Hz significantly lighter than
>>> one of the same VA rating designed for 50Hz ?
>>>
>>> Jim Hawkins
>>
>> Following on from this, why is it that electricity generation is
>> limited to such low frequencies as 50 or 60 Hz ?
>> As the frequency rises, the energy lost through electromagnetic
>> radiation from the wires rises, but is it really a significant amount
>> ? Would it be significant at 1 kHz ? If not, why isn't generation
>> done at that sort of frequency ? The savings in transformer weights
>> and sizes everywhere would be enormous. Is it because of mechanical
>> engineering limitations on the rotational speeds of the large rotary
>> generators the power stations use ?
>>
>>
>>
>
> I have worked in the airforce, they also used 400 Hz
> on(or under) the ground.
> You could hear the 3rth harmonic(1200 Hz) all over the
> place, wich is not such a good idea in your home.
> Very iritating for new workers, old workers had a
> measurable dip in their hearing curve, and could not
> hear that frequency anymore.Permanent damage.

Apparently they had line frequencies as 16.66 Hz and other strange stuff
like 25Hz, which was last used in the US for railway lines.

Here's a little about this:

http://www.nycsubway.org/articles/rotary_converter.html

On 26 Jan 2012 23:50:39 GMT, Sjouke Burry <s@b> wrote:

>"Jim Hawkins" <(E-Mail Removed)> wrote in
>news:(E-Mail Removed) om:
>
>> Jim Hawkins wrote:
>>> Is a mains transformer designed for 60Hz significantly lighter than
>>> one of the same VA rating designed for 50Hz ?
>>>
>>> Jim Hawkins
>>
>> Following on from this, why is it that electricity generation is
>> limited to such low frequencies as 50 or 60 Hz ?
>> As the frequency rises, the energy lost through electromagnetic
>> radiation from the wires rises, but is it really a significant amount
>> ? Would it be significant at 1 kHz ? If not, why isn't generation
>> done at that sort of frequency ? The savings in transformer weights
>> and sizes everywhere would be enormous. Is it because of mechanical
>> engineering limitations on the rotational speeds of the large rotary
>> generators the power stations use ?
>>
>>
>>
>
>I have worked in the airforce, they also used 400 Hz
>on(or under) the ground.
>You could hear the 3rth harmonic(1200 Hz) all over the
>place, wich is not such a good idea in your home.
>Very iritating for new workers, old workers had a
>measurable dip in their hearing curve, and could not
>hear that frequency anymore.Permanent damage.

I had dips at 2400 and 4800 Hz as well as 1200 when i was done with the
navy.

?-)