Andy Pugh wrote: > I had an eBay "accident" last night and I have bought 3 > resolver-feedback servos. > > Looking at ways to drive them, I have found the Analog Devices > AD2S1200 chip, which basically connects to a resolver and outputs the > position and/or velocity as simulated quadrature encoder, 10-bit > parallel and 3-wire serial. > > The ICs are not inexpensive at £24 from RS, though I have found a > couple on eBay if any of the US residents fancy a fiddle. > I make a resolver to quadrature converter board. One problem I have run into is that there are different forms of resolvers. Transformer-type resolvers, sometimes called "brushless resolvers" usually have low drive current requirements. Variable Reluctance type resolvers have nothing but shaped iron laminations in the rotor (no windings) and require a lot higher drive, up to hundreds of mA. So, my current resolver board can't handle those units. I have had really good results with Harowe Controls resolvers in the NEMA size 11 servo housing.
The velocity output of the AD chip is worthless, as it is a 12-bit plus sign number, with full scale at 60,000 RPM. So, the minimum reading is 30 RPM. I just bring out the quadrature plus index pulse. Jon ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
