Originally Posted by jmelson  It looks like this servo drive needs industry-compatible "Hall" signals, but my converter (so far) does not produce them. It does have an absolute position output that could be decoded to provide the commutation signals, but I just haven't gotten around to making that board. I don't know if anyone else has made a converter that will do this. Probably a PIC microprocessor could be programmed to do the job pretty easily. The board produces 4096 discrete position values for a full revolution. Most brushless servo motors are 8 pole. So, you need to divide the absolute position into 24 steps that repeat through the 6 commutation codes. Of course, if your motors ALSO have the Hall outputs, you don't need to go through these gyrations, and the resolver converter will work as is. |
Of the four or so Pacific Scientific motors I have, I don't think a single one of them has Hall outputs. I have found a PLC-type box from I2T (modicon) that claims to have a resolver/digital converter
(datasheet). I haven't received it yet, but I'm hoping that it will work for my purpose. We'll see if I manage to let all it's magic smoke out, and I'll post the results.
As you know vast amounts more about this issue than I do, what does it take to convert an analog resolver signal to an encoder signal? The only reason I ask about going the encoder route is due to the fact that I have these drives laying around. Is there a better route to take? Most importantly, are there any servo drives that you know of that:
1. Accept resolver feedback.
2. Work for AC, brushless servos.
3. Accept Mach3 step/direction commands.
4. Output moderate power levels (15-25 amps).
Sorry for so many questions, but both you and Al are a vast warehouse of knowledge, and I need all the help I can get.
Thanks, Chris