Quote:
Originally Posted by AndrewJ
Gday Freddy
Re
This device is also being discussed on the LX200GPS Yahoo forum
Someone found the specs for the device as
The specs for the ERN-480 models show only up to 6000 lines
( which in quadrature mode gives about 54arcsec granularity )
As such, something else is going on, probably a precision geartrain between the RA axle and the encoder.
This may have PE in it, but that could be accounted for easily in the "black box" ( dunno if it is )
Also, unless the device takeoff is perfectly centred, you would still get slight tracking rate errors due to eccentricity
( assuming we are talking of 1/8 arcsec precision )
Soooo, it looks like a good device to remove the bulk of the geartrain errors, but guiding is probably still required.
Andrew
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Hello!
I just read datasheets for Heidenhain encoders and I think they use model ERN 480 with sinewave incremental signal output.
Here is citation from datasheet:
HEIDENHAIN encoders with sinewave output interface provide voltage signals that can be highly interpolated.
At photo
http://www.slas.us/gallery2/main.php?g2_itemId=1386 there are 2 IC's at the left side of the box, I think it's a OP amplifiers, but what IC is on SOIC adapter? Probably 2 channels ADC...
Simple use of hi-res encoder on RA shaft - it's too expensive! That is why company asks their customers to not publish labels on the encoder, but it is very simply to discover by form... and nevertheless on one photo is visible number 5000
Yep, price is too hi for this device!
Cheers!