[Milsurplus] 400 cycle 3 phase and WW2

[J. Forster]

Very astute observation. Most of the indicators you see surplus are,
indeed, selsyn types.

The inverters for the fluxgate compasses were very cute. Sadsly, I took
mine appart as a kid. I think they output <10 Watts.

-John

===============

> My impression of the early use of 115v 400cy (pre war/early war) was for
> selsyn transmitters used for instrumentation. Instead of direct reading
> instrumentation where you would have to run tubing from the engines to the
> cockpit they elected to use selsyn transmitters and instruments.
>
> Many of the fighters and bombers had selsyn instrumentation for things
> like
> fuel flow, oil pressure, fuel pressure etc. This would also limit the
> amount
> of flammable liquids in the cockpit.
>
> There was also a problem of the fluids in the long runs to the cockpit
> congealing in cold environments (especially engine lubricating oil) thus
> causing instrumentation errors both on the ground and in flight.
> Mechanical/hydraulic transmitters were tried on several aircraft where the
> fuel or oil would flow through a short run of 1/4 inch line to the
> transmitter. This transmitter has a diaphragm that has the engine oil/fuel
> on one side and then a special fluid (compass fluid) on the other side of
> the diaphragm which would then be run to the cockpit. This instrumentation
> fluid would not congeal in the extreme temperatures and was not as
> flammable
> as the fuel being piped to the instruments.
>
> The flux gate compass system and some gyros for autopilots used 115/400cy
> in
> WWII aircraft as well as some radio and most radar gear. The Sperry S-1
> bombsight and A-5 autopilot also used 115/400cy for its main power. The
> Norden sight used 28vdc but the C-1 autopilot had its own 115v inverter
> instead of relying on the ships inverter or inverters/dynamotors.
>
> The remote compass system common in smaller aircraft where the flux gate
> was
> too big also used AC but it was 26 volts at 400 cycles. These systems used
> a
> small rotary inverter just for the compass which was smaller than the
> dynamotor on an ARC-5/274N receiver.
>
>
> Taigh
>
> Taigh Ramey
> Proprietor, Vintage Aircraft
> 7432 C.E. Dixon Street
> Stockton, California 95206
> (209) 982-0273 Shop
> (209) 982 4832 Fax
> www.twinbeech.com
> 'KEEP 'EM FLYING...FOR HISTORY'
>
>
> -----Original Message-----
> From: milsurplus-bounces at mailman.qth.net
> [mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of Jack Antonio
> Sent: Wednesday, January 12, 2011 11:09 AM
> To: milsurplus at mailman.qth.net
> Subject: Re: [Milsurplus] 400 cycle 3 phase and WW2
>
> I  remember reading that the Douglas XB-19 which was
> used as a test bed for large aircraft systems, used AC power,
> but no technical details were provided.
>
> Jack Antonio WA7DIA/4
>
>
>
> On 1/12/2011 1:46 PM, Ray Fantini wrote:
>> Thought all the old WW2 stuff ran from 28 volts DC and the B-36 was the
> first aircraft to exclusively use 115 volt 400 cycles 3 phase AC
> distribution? Being that AC distribution reduced design weight by several
> thousand pounds on a large aircraft. Recall reading something along this
> line in "Magnesium Overcast" by Dennis Jenkins. Maybe there was some
> application of 400 cycle AC prior to the B-36 but don't know what it would
> be. Did the old GO and GP transmitter have engine driven generators or
> motor
> generators  to develop their voltages from the ships DC distribution?
>> Ray Fantini KA3EKH
>>
>> ______________________________________________________________
>> Milsurplus mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/milsurplus
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Milsurplus at mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>
> ______________________________________________________________
> Milsurplus mailing list
> Home: http://mailman.qth.net/mailman/listinfo/milsurplus
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Milsurplus at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1191 / Virus Database: 1435/3375 - Release Date: 01/12/11
>
> ______________________________________________________________
> Milsurplus mailing list
> Home: http://mailman.qth.net/mailman/listinfo/milsurplus
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Milsurplus at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>