Re: [Insert other state here] Airport lines

[Daivd R <spillNOspSPAM@cyberdude.com.invalid>]

It shouldn't be any more difficult than the normal voltage
change-overs on the heavy rail network. As long as the
electrical system is designed to operate at the highest voltage,
then there's no reason why there would be problems. Thats
speaking as an electrical engineer rather than knowing exactly
how things work in this case.

An example system would be to have two seperate power systems
and a simple automatic switch. The initial state of the switch
is neutral. When a voltage is applied, the controller determines
which level and sets the switch. When the voltage is
disconnected, the system resets to neutral and the process
starts again. If a suitably long insulated section were used
between high and low voltages (to give time for the controller
to reset), then you have a cheap solution. The DC/AC changeover
would cause more problems that the voltage change over as it
means you need to be able to switch a transformer in and out of
the circuit.




In article <3930d847.36784517@news.ocean.com.au>,
pcc@ocean.com.au (Brown Family) wrote:
>On Sat, 27 May 2000 20:03:22 +1000, Colin Weaver
><weaver@powerup.com.au> wrote:
>
>>Feasible.  In Germany (Karlsruhe) there is light rail which
shares
>>infrastructure with high voltage AC heavy rail (25KV or
~16KV), and can
>>also run under 750V DC.
>>
>How is this done?
>
>Unless you run 47 of them in series together (25KV), some form
of
>collection power attentuation must kick in pretty fast before
you
>savage the semiconductors. Even some form of PWM couldn't
possibly
>react fast enough.
>
>Les Brown
>
>Freedom's just another word for nothin' left to lose.
>
>


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