Hi Kirk,
I've come in late to this thread. Could you just put a resistor between the +10 and 0V terminals on the VFD 'complete' the circuit that the potentiometer would. Then then feed the output of your DAC to the Vin terminal of the VFD? Cheers, Peter. Kirk Wallace wrote: > On Sun, 2008-01-27 at 16:22 -0500, Stephen Wille Padnos wrote: >> Kirk Wallace wrote: >> >>> I got my serial DAC prototype working, but the first VFD I hooked up >>> would not accept a voltage only signal, it needed a potentiometer on the >>> +10 V, Signal and 0V terminals. The other VFD's used a voltage across >>> the signal input and 0V just fine. Does anyone know how the one VFD >>> input might be different and a good way to adapt to it? I could use a >>> serial potentiometer but they usually have a low resolution and it would >>> be another project to get done. Thanks. >>> >>> >> There should be 10-bit resolution serial pots. That's close enough for >> a spindle - it's 10RPM resolution on a 10000 RPM spindle. It would >> probably be better to get an audio (or logarithmic) taper, so you have >> more resolution at the low end. >> >> Here's one from Analog devices at DigiKey: AD5231BRUZ10-ND, $4.19 >> single qty. >> >> - Steve > > I suppose it wouldn't be that hard to massage my DAC component to work > with a digital pot. I actually have one (an AD5290) on the bench that I > could try. I just looked at the datasheet, and all's I need to do is > reduce the number of bits from 12 to 8. But it's nice and warm where I > am right now. > -- ------------------------------------------------------------------ Web: www.homanndesigns.com email: [EMAIL PROTECTED] Phone: +61 421 601 665 www.homanndesigns.com/ModIO.html - Modbus Interface Unit www.homanndesigns.com/DigiSpeedDeal.html - DC Spindle control www.homanndesigns.com/TurboTaig.html - Taig Mill Upgrade board ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
