[simpits-tech] Need a power supply...

[Matt Bailey]

On Tue, 8 Apr 2014 08:14:08 -0700 (PDT)
geneb <geneb at deltasoft.com> wrote:

> On Mon, 7 Apr 2014, Matt Bailey wrote:
> 
> > On Sun, 6 Apr 2014 14:12:49 -0700 (PDT)
> > geneb <geneb at deltasoft.com> wrote:
> >
> >> On Sat, 5 Apr 2014, Matt Bailey wrote:
> >>
> >>> On Fri, 4 Apr 2014 08:47:04 -0700 (PDT)
> >>> geneb <geneb at deltasoft.com> wrote:
> >>>
> >> Yep, right Matt. :)
> >>
> >> Because the F-15 ADI & HSI are essentially irreplaceable, I'm going
> >> to give them *precisely* what the specs say they need.
> >
> > Quite understandable. I feel the same way about the pair of Collins
> > ADIs I have for the Sabreliner. I'm still itching to grab some
> > synchros from something around here (perhaps my ADF heads...) and
> > see how they react to house voltage. If I can test enough synchros
> > long enough with house voltage and all is well, I might try it on
> > complete instruments. It would *vastly* simplify power delivery.
> >
> I wouldn't do it.  You'll burn them up.  I talked to Mike Powell
> about this and his comments were:
> 
> "If the synchro is rated for 400Hz its impedance will be too low at
> 60Hz and too much current will result. Smoke, heartburn, stale beer,
> etc. etc.
> 
> When running a synchro at frequencies other than the nominal, scale
> the voltage with the frequency.  So, at 60Hz, a 115VAC/400Hz synchro
> would be better powered by (115) * (60/400) = 17.25 VAC."

Interesting, good info to know! Well, stepping down house voltage is a
lot easier than getting 400hz, so this is still good news.

Still....I think I will take a couple of "throw away" synchros from an
old ADF or something, and just see how they react. :)


> A stepper will keep its position as long as it's powered and the
> force on the output shaft doesn't exceed the holding torque rating
> for the stepper. In binding a stepper to a synchro transmitter, that
> will NEVER happen.

I need to experiment with them more, sounds like they might be quite
useful.


> Here's another question - can you safely use a standard meter to
> measure AC current @400Hz or will that higher frequency kill the
> meter?

My cheapy DMM has no problem with it. Of course, YMMV, INAL, DTTAH, etc
etc. :P

-- 
Matt Bailey

Keeping It Real:
Sabreliner 60 Flight Simulator
Serial # 306-61 - N1JX
http://sabrelinersim.com