RE: [TCML] 50Hz = 'short end of the stick?'

[davep@xxxxxxxx]

>> > For example, a line frequency which is lower results in a
>>> less-efficient transformer (weight:wattage)

>>     Low frequency, if designed for, is higher efficiency in
>>     the transformer.  Hence (as noted) the past (and, indeed,
>>     present) use of 25 Hz, 16 2/3, etc in specific applications.

> First, I would like to ask for a reference on this subject;
       We're getting a bit away from 'practical coiling'.  For
       reference see any engineering hand book with properties
       of materials, any set of engineering papaers.

> it seems that the opposite would be true. For example, do aeroplanes
> not use 400Hz transformers and 'line' frequency?
       Yes.  That application trades more expensive core material
       for weight reduction, since it has to fly.

> Is this not because the weight of the transformers can be reduced,
> due to the higher frequency having a higher saturation-point in
> the laminations?
      And use of laminations/materials optimized for HF: trading
      cost for weight.  Additionally, materials change, new
      ones become available, as was noted: better steels, use
      of ferrites.

> Or, is the type of efficiency you speak of purely electrical
      Indeed.  Which efficiency is of interest?  I note that
      Tesla designed the Niagara power installation for 25 Hz...

> and in total neglect of materials expense?
      All design is a trade off.  Helps to specify _which_
      'efficiency' is of interest, and how much each costs.

> If that's the case, then if there are fewer voltage reversals
> in a given time, of course there's going to be a potential for
> a greater efficiency, as long as you are speaking in purely
> watts(in):watts(out) terms.
      Thats a common definition of efficiency....

      best
       dwp

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