On 22 June 2011 04:12, Edward Bernard <yankeelena2...@yahoo.com> wrote:
> I have thought about replacing the potentiometer with an interface to > EMC2 and would love to hear any ideas to accomplish this. My first thought > was > to use an Arduino board to accept a PWM signal and control a digital pot. Any > better (simpler) ideas? I think this circuit ought to work https://picasaweb.google.com/bodgesoc/Gibbs#5621046688941452194 Which is something I have meant to try for a while. I have a feeling I have drawn it before, and that time I was more confident in it, I think I have left out some critical resistors. The idea is that it converts a 5V PWM to a completely isolated voltage, which could be to a different reference, and of a different magnitude. I imagine connecting it in place of the pot on a VFD for example, or to the 100V floating pot terminals on a KBIC controller. It is effectively half of a H-bridge, +5 PWM turns on an opto that discharges the capacitor, and 0v PWM turns on an opto that charges the cap. As-drawn there is a problem that unconnected PWM turns on both optos... -- atp "Torque wrenches are for the obedience of fools and the guidance of wise men" ------------------------------------------------------------------------------ Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Data protection magic? Nope - It's vRanger. Get your free trial download today. http://p.sf.net/sfu/quest-sfdev2dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
