It was almost certainly for powering a WWII vintage fluxgate compass system.
-John ============== > I have a little dynamotor somewhere which makes 3 phase 400 Hz. Tiny > little > thing! Only puts out like 15 VA, and not very noisy either. IIRC is was > called > an "Instrument inverter" > > > > On 3/27/2013 9:55 PM, Bob Camp wrote: >> Hi >> >> If three phase is actually needed, I'd suggest something like a cheap >> PIC with three PWM outputs. Fairly simple R/C's on the outputs should be >> plenty good enough to filter out any crud. Good frequency stability / >> accurate phase shift / cheap. What's not to like . >> >> Bob >> >> On Mar 27, 2013, at 9:44 PM, kb0...@juno.com wrote: >> >>> Bill Ezell; >>> >>> Your Gyro may require 3 phase, 400 cps, 28 vac, Sine wave. >>> >>> A simple "Buffered Phase Shift Oscillator" for 400 cps can create the >>> Sine Wave. >>> https://www.circuitlab.com/circuit/h6v28g/buffered-phase-shift-oscillator/https://www.circuitlab.com/circuit/bakd83/phase-shift-oscillator-ii/You >>> will need to add an AGC to the output for frequency stability. >>> A "3 Phase Generator" can create the 3 phase >>> output.https://www.circuitlab.com/circuit/m4u5nw/3-phase-generator/ Add >>> 3 Amplifiers (one for each phase) to reach voltage/power. >>> If the Gyro is directional, it will take several hours to stabilize. >>> >>> Carl >>> ____________________________________________________________ >>> Refinance your home now >>> Loans under 729K usually qualify for US GOV backed refinance programs >>> http://thirdpartyoffers.juno.com/TGL3131/5153a0bf2812c20bf6124st04duc >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> >> ----- >> No virus found in this message. >> Checked by AVG - www.avg.com >> Version: 10.0.1430 / Virus Database: 2641/5707 - Release Date: 03/27/13 >> >> >> > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.