On 30 September 2011 02:24, Kirk Wallace <kwall...@wallacecompany.com> wrote:
> I decided to try a > different approach and rigged up an opto-isolator which switches the 10V > speed supply to the 0-10V input. I feed the transmit side of the > opto-isolator with a PWM signal. I am not clear what you have here. Are you connecting the Opto output direct to the speed control pin? Or do you have an RC network that you haven't mentioned? Is the VFD designed for PWM input? If not you may be using an input filter cap as a PWM integrator. (and a series resistor on the input might stretch the range for you, probably at the expense of linearity). I designed a dual-opto push-pull circuit for PWM to (isolated) voltage but as I have never tried to use it yet I am reluctant to show it again. -- atp "Torque wrenches are for the obedience of fools and the guidance of wise men" ------------------------------------------------------------------------------ All of the data generated in your IT infrastructure is seriously valuable. Why? It contains a definitive record of application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-d2dcopy2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
