----- Original Message ----- From: "Andy Pugh" <[email protected]> To: "Enhanced Machine Controller (EMC)" <[email protected]> Sent: Sunday, April 25, 2010 8:57 AM Subject: [Emc-users] Resolver to Quadrature Convertor
> Firstly let me make it clear that functional, competent, accurate and > reliable Resolver to Quadrature convertors are available from Pico > Systems and Mesa Electronics: > http://pico-systems.com/resolver.html > (I can only find a mention of the Mesa 7i49 on the price list, but I > understand it does exist) > > Furthermore there are commercial chips to do the conversion too: > http://www.analog.com/en/analog-to-digital-converters/synchroresolver-to-digital-converters/ad2s1200/products/product.html > > For reasons that I am not clear of myself, I eschewed all such > approaches, and decided on a DIY approach, using an Arduino board. I > have written it up on the Wiki. > > http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?ResolverToQuadratureConverter > > It handles 3 resolver channels and has been tested to 1600 rpm (the > max speed of my cordless drill). Bench testing indicates that the > quadrature pulses should keep up up to 3750rpm. For higher speeds it > would be necessary to run fewer resolver channels. > > -- > atp > > ------------------------------------------------------------------------------ I have a couple of servo motors I bought surplus, haven't used them mainly because the have resolvers and uses the resolver for commutation. Some day when/if I need to use them the plan was to buy an amp that would work with them. >From your project I gather that a home made amp might be do-able reading 1 resolver and driving 3 half H-bridges to control a motor. I'm guessing to figure the timing between the resolver and fields it could be ran open loop like a stepper and record the resolver following angle between forward and reverse. From there perhaps calculate the optimum angle for the field phases to the resolver position. And after all that, give quadrature output for EMC2 to know the position. In your opinion, do you think the Arduino would work to use as an amplifier by using 1 resolver and adding 3 phases of PWM to drive 3 half H-Bridges? Thanks Roger Neal ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
