Re: [CAD_CAM_EDM_DRO] Sony Magnescale

unterhausen wrote:

> I am currently the high bidder on 2 Sony Magnescales on Ebay. In
> typical form, I bid thinking they were optical. Now I realize that
> they are magnetic. I am left wondering if I can use them, at least
> without spending another $1000 (heh, the cables to connect them to a
> dro are $400 each). I think the excitation on these things must
> normally be in the DRO, but I'm not sure. It appears that some
> models are meant to interface to cnc, but the ones that aren't are
> not easy to interface to.

I would not immediately assume it needs AC excitation from the DRO
box. There were old linear resolvers and inductosyns that were just
3 coils on the end of the cable, and all the processing was in the box.
What you say is true for them. I believe the Sony scales use a permanently
magnetized scale and a readout head using the giant magnetoresistive
effect, which is now used in computer disk drives.

> If you want to outbid me, they are items 1685604339 and
> 1685605785. That will answer all my questions. Otherwise, if anyone
> could point me towards some useful interface information, I would
> really appreciate it.

Here's a page from Sony, but I don't find the exact model listed :
http://www.sonypt.com/product/nc_linear_encoders.html
But, the scales shown all seem to have A/B quadrature outputs.
(If the cables are really $400, they may put the electronics in the
cable, though.)

Jon