On Tue, 2012-01-24 at 12:26 -0600, Jon Elson wrote: > Kirk Wallace wrote: > > > > but I used the paradigm of a switch closure at the time I did the > > installation, after giving it more thought and referring to: > > http://pico-systems.com/images/univstep.png > > > > it looks as if the inputs already go to an opto-isolator on the UPC > > anyway. It may be that a resistor (and a general purpose diode for > > reverse voltage protection) in series would work just fine. Limiting the > > current to the opto LED is the primary issue. The UPC and turret encoder > > 12V supply grounds would need to be tied together in order to close the > > circuit. The logic sense may need attention too. > > > Yes, that is what I'd recommend. I think only the diode is needed, the > resistor is already > provided in the UPC board. > > Jon
Just in case, my guess is that the internal resistor was sized for current limiting 5 Volts, so the current would go up by around 120% without an external resistor, which is okay? -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA ------------------------------------------------------------------------------ Keep Your Developer Skills Current with LearnDevNow! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-d2d _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
