[amsat-bb] Re: Motor for Yaesu G5500 Azimuth Rotator?

[Joe Fitzgerald]

On 2/25/2012 4:25 PM, Phil Karn wrote:
>
> If it really was a 3-phase induction motor then there *had* to be some
> sort of phase shift at least to start it.

Of course you are right.  I found a schematic of their controller

http://www.ecse.rpi.edu/courses/CStudio/ham_radio_docs/Prosistel61C.pdf

The phase shift is done with C7 and C8, but I have to spend some time 
with the schematic to figure out exactly what they are doing.  I 
expected to see a microcontroller/DSP individually controlling each of 
the 3 legs.

-Joe KM1P