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
Shucks, the AD5231 wiper will only take 5 Volts max. I have an AD5290 which will take 30 Volts with 256 steps, but it is so small I can barely see the lead spacing (10 pin MSOP). The AD5280 goes to 15 Volts with 256 steps and comes in a TSSOP, which is about twice the size. These people have a MSOP board though. I get the feeling these boards will come in handy. Can .5 mm lead spacing be mechanically etched? -- Kirk Wallace (California, USA http://www.wallacecompany.com/machine_shop/ Hardinge HNC lathe, Bridgeport mill conversion, doing XY now, Zubal lathe conversion pending) ------------------------------------------------------------------------- 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
