Re: [MV] 12V - 24V - 36V

R. C . Orpe (sgtorpe@sierratel.com)
Sun, 11 Jul 1999 08:55:35 -0700

400Hz AC is also closer to a straight line DC voltage in terms voltage
fluctuation. Avionics likes the reduced fluctuation better.

As a side note, you need to have a source of power when you get a newer MV
started to flash the field in the alternator to start it charging. As an
example: you can push start an M35A2 and it will run fine, but the lights
won't work until you "flash" for a power source.

Randy
-----Original Message-----
From: Richard Notton <Richard@fv623.demon.co.uk>
To: mil-veh@skylee.com <mil-veh@skylee.com>
Date: Saturday, July 10, 1999 11:54 AM
Subject: Re: [MV] 12V - 24V - 36V

-----Original Message-----
From: jonathon <jemery@execpc.com>
To: mil-veh@skylee.com <mil-veh@skylee.com>
Date: 10 July 1999 05:36
Subject: RE: [MV] 12V - 24V - 36V

>>. Can someone more
>>electricly inclined than I explain why some mil equipment some as missile
>>systems and sonar systems run at 400HZ / rather than 60HZ?
>
>For inductive components (transformers, motors, etc.) the higher the
>frequency (within reason else other problems crop up) the smaller the
device
>to achieve the same end goal. Why 400Hz in particular was standardised on
>I'm not sure but the reason for the high frequency is weight and size
>reduction of the components. The avionics systems I was involved with all
>ran on 120VAC 400Hz 3 Phase-Y and 28DC, which I think is pretty typical of
>aircraft stuff in general??
>
Spot on.

A 400Hz supply does indeed mean small, light transformers and also the
unreliable high value electrolytic capacitors in PSU's can also be designed
out.

3Ø supply in 400Hz star and delta configurations are common on UK warships
too
along with 1260Hz supplies mainly used in synchros and resolvers.

Richard
(Southampton UK)

===
To unsubscribe from the mil-veh mailing list, send the single word
UNSUBSCRIBE in the body of a message to <mil-veh-request@skylee.com>.

===
To unsubscribe from the mil-veh mailing list, send the single word
UNSUBSCRIBE in the body of a message to <mil-veh-request@skylee.com>.