----- Original Message ----- From: "Edward Cole" [email protected] To: "Howard Long" [email protected]; [email protected]; "'Henk, PA3GUO'" [email protected]; [email protected] Sent: Tuesday, January 01, 2008 7:55 PM Subject: [amsat-bb] Re: [SPAM] RE: Re: Making your own rotator controller
Does anyone know of a rotator interface for controlling selsyn motors?
73, Ed - KL7UW
Hi Ed, KL7UW
Unfortunately I know only how to use selsyn motors as position indicators. I use selsyn motors instead of potentiometers only as precise position indicators to show the angular position of AZ and EL in the shak for my 2400 MHz dish. The shaft of the antenna is mechanically coupled with the shaft of a transmitter selsyn motor with a ratio 1/1 while another receiver selsyn motor is in the shak and has a mechanical index in the shaft to show the angular position. Both selsyn motors transmitter and receiver are supplied in parallel with AC voltage R1-R2 for the rotors and S1-S2-S3 for the stators.
If I need a digital indication instead of a mechanical index indication then the Analog Device AD2S80A series of variable syncro/resolver-to -digital converters is the chip to be used. In addition this chip has a DC output that supply a linear 0-5 volt DC for a 0 to 360° digital indication and this voltage can be used as feedback with any available tracking program for automatic traking.