Hi The first question is "how much 400 Hz power do I need?". Without knowing if it's tens of amps (no, it's not…) or a tenth of an amp, it's a bit though to decide how much to spend on the solution.
Eight ohms at 28 volts would be just a bit under 4 amps. It's also right at 100 watts. I'd be very surprised it you need anywhere near that much current. You probably want a pure sine wave to keep everything happy. A lot of the simple inverters are "sort of" sine waves. I think I'd vote for something like an cheap audio amp driven by a nice clean / stable 400 Hz tone. Bob On Mar 27, 2013, at 4:40 PM, Bill Ezell <[email protected]> wrote: > Well, I can come up with something topical, read on. :) > > I saw a 'Bendix yaw-rate gyro' on FleaBay recently for $14.50. Of course, I > had to buy it. > > What I got was the yaw-rate gyro package from a Northwest Airlines DC-10 that > was stripped for parts around 2000. The gyro included the pull tag with tail > number, the license number of the A&P mechanic that pulled it, and some other > cool stuff. > > What it turned out to really be is two gyros with two sets of electronics in > one box about 6" x 2" x 5" box, all vintage '80s or so. Even better, it's a > strapdown system. The actual gyro wheel is about the size of your thumbnail. > I've just started tracing things out, and I've gotten the gyros to spin up. I > really love mechanical gyros for some reason, too bad there's not a gyro-nuts > group. I'm going to have great fun getting the package traced out and running. > > So, to be a bit more topical, the package of course needs 28V 400Hz for the > gyros, 28VDC for something, and +/-15V for most of the electronics. > > Question - anyone figured out some clever solution for the 400Hz power? I > faked it with a signal generator and power amp, but that's a bit bulky. I'm > thinking I'll use one of the class-D amp ICs and a simple op-amp phase-shift > sine generator. > > Topical in a more abstract way, strapdown systems really are very > interesting. They require precise integration of the rate output over time to > derive velocity and position, and really weren't practical until the 70's > when small enough computers existed to do the requisite calculations. (I > worked on the nav system for the Trident missile back in my Draper Labs days). > > -- > Bill Ezell > ---- > They said 'Windows or better' > so I used Linux. > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
