[Milsurplus] Hig frequency power

Peter Gottlieb nerd at verizon.net
Wed Mar 22 23:39:47 EST 2006


Really?  I never thought about that, nor did I ever get into AC motor design. 
Seems reasonable though.

The power control unit I had was beefy for gyros, IIRC it had several 
distribution circuits of 20 amps 3 phase 120/208 and was very specifically rated 
at 1600 Hz.  That seemed so odd I remember it to this day.  I picked it up from 
some surplus place on Canal St in NYC probably around 1970.  Although my memory 
of details of it are sketchy, I believe it was for aircraft use.  1600 Hz would 
get you some very fast gyros.

What else would such a power frequency be used for?  I would think it would be 
very annoying bleeding into any audio circuits.



J. Forster wrote:
> There is a good reason for higher frequencies in Gyros. Generally you want the
> rotor to spin very fast to maximize the rotor's angular momentum.. You cannot
> get an AC motor to run faster than synchronous speed, 3600 RPM for 60 Hz; 24,000
> RPM for 400 Hz. Hence the higher operating frequency,
> -John
> 
> 
> 
> William Donzelli wrote:
> 
> 
>>>I once had a power control unit which said it was designed for 1600 Hz
>>>and was 3 phase, but I have no idea where it was used.  Always
>>>wondered about that.
>>
>>Perhaps a gyrocompass? Sometimes thay use really odd line frequencies
>>(Armas used 233 Hz, I think some Sperrys 240 Hz). Like most things gyro,
>>there is probably a perfectly valid reason for using these, known by four
>>people in the whole world (and only two of them understand why).
>>
>>William Donzelli
>>aw288 at osfn.org
> 
> 
> 
> 
> 


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