[TowerTalk] Telrex rotator with sychro

[jimlux]

On 11/22/18 2:16 AM, Peter Voelpel wrote:
> Me too.
> 
> I use synchros in three of my rotators, one HyGain and two homebrew.
> At the moment I coupled a helipot mechanically to the receiving synchro for
> presets and end of travel switching.
> Synchros are still available on Ebay and military surplus shops so I will
> continue to use them whenever I need a direction indicator but would like to
> transfer bearing data to my contest program.
> 
> Hans, anymore info about the IC types and the application you are aware of?
> 


Analog devices
https://www.analog.com/en/products/ad2s44.html
AD2S44 "Low Cost 14 bit, dual channel synchro/resolver to Digital 
Converter"
Hybrid 32 pin DIP, $2,202.27 from them.

Uses an internal solid state Scott-T to turn V1,V2,V3 into sin/cos 
resolver, and then converts it using a form of PLL.


https://www.analog.com/en/products/ad2s90.html#product-overview
The AD2S90 is a 12 bit resolver to digital converter.  It *is* a lot 
cheaper ($35)
You'd need a Scott-T to make this work with a synchro

The big problem is that the excitation frequency has to be between 2-20 
kHz. and it wants to see 2 Vrms on the input - you can probably run a 
400Hz synchro on 2kHz.

https://www.analog.com/en/products/ad2s83.htmle
this $80 unit is also a resolver-digital, so you'd need a Scott-T. It 
does have a minimum frequency of zero


DDC (http://www.ddc-web.com) is a supplier of synchro/resolver to 
digital for decades.
It looks like they have a RD-19242 monolithic resolver-digital converter
http://www.ddc-web.com/Products/281/Default.aspx
no price info..

The data sheet does have a suggested resistor network you can use to do 
synchro to resolver conversion
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