On 12/9/2015 2:26 AM, Attila Kinali wrote:
Moin,I just tried to figure out how phase microsteppers are usually build, but, beside the time-nuts discussion from 10 years ago and US patents US4358741 and US4417352 my search turned out empty. I am pretty sure that I used the wrong search terms and there should be lots of documentation out there. Can someone give me a hint what to look for? Attila Kinali
My extensive experience with digging up old articles (before the internet, the library was like my second office) is that when
the trail goes cold on some topic for no apparent reason, it turns out that there is a (non-apparent) good reason why no one is writing about the topic any more. I usually got to the bottom of this by asking experts in the industry. My general impression about phase microsteppers based on when I was involved in the time industry is that they didn't have a very good reputation and were an inferior solution that was used as an expediency because it it could be "bolted on" to an existing system that wasn't originally designed to be tuned. I think the concensus was that direct digital synthesis is the better way to go, assuming you can design it into the architecture in the first place. DDS is a pretty well developed technology at this time that is supported by good OTS chips, so it is not clear what the value proposition would be for phase microsteppers. When we were designing the 5071A 25 years ago, it was clear that the method of tuning by varying the C field was not acceptable for a state of the art standard. There are multiple reasons for this decision. At the time, there were a few DDS chips, but we had to roll our own DDS due to the stringent and specialized requirements. It took a whole PC board for this circuit at the time. The possibility of using a phase microstepper was never even considered AFAIK. Are you aware of some redeeming value that phase microsteppers have that would make us want to investigate them? Am I being too harsh on them? Maybe you can champion them and they will make a come back :-) Rick Karlquist N6RK _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
