Hello Dave, Chris & PIC.ers, Nooope. Never heard of variable caps. or resistors in this app. They're `Linear' quadrature AB encoders, just the same as the usual rotary ones, but optics laid out flat. Electronics the same. I interface them regularly into PIC projects that require distance measurement / control, using an isr to read the status of each line (hi..lo) and implementing a state machine to track the increment or decrement of each signal edge. best regards, John >Date: Fri, 22 Nov 2002 19:45:26 -0800 >From: Dave King >Subject: Re: [EE]: Better than using OT... > >At 10:39 PM 22/11/02 -0500, you wrote: >>Does anyone know what technology is used on the DRO's used on metalworking >>machine tools? >>The ones I had used what they called "glass slides", one for each axis. I >>never took one apart to look closely, but I have searched for this and come >>up short. I would think this would make an interesting PIC project for all >>of us with home workshops.... >>Chris > >They are either variable capacitors or resistors. You can buy the strips >from several places. > >Dave > e-mail from the desk of John Sanderson, JS Controls. Snailmail: PO Box 1887, Boksburg 1460, Rep. of South Africa. Tel/fax: Johannesburg, South Africa (011) 893 4154 Cellphone no: 082 741 6275 email: jsand@pixie.co.za Manufacturer & purveyor of laboratory force testing apparatus, and related products and services. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads