Resolvers, anyone?

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I need to interface to a resolver. The speeds and resolution are not too daunting.

Shall I roll-my-own interface, or plan on using a resolver-to-digital converter? Low-cost please--for this application precision is not that important, as long as position is not lost.

Lee

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

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Syncro Resolver ??

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what is a resolver?

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I know what a revolver is, but not a resolver. hmm.. Avr controlled 6-gun revolver...

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Hi lee,
I am interfacing a synchro to an avr (got it working this morning) using a chip from DDC. They supply Synchro to Digital Converters as well as Resolver to Digital Converters. The Synchro to Digital's are "very" pricey (about $1100) but the Resolver to Digital's are a lot less (about $340). The chips provide 16bit resolution with very little control needed on your part. The website also has general info on synchros and resolvers so check it out on www.ddc-web.com.

Graeme

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Hello Lee,

Try Analog Devices for some Digital Resolvers Interface as well actual devices. I agree with Graeme that DDC is probably the most expensive solution around. Expect to pay in the bracket of $150 to $1500 for a mediocre to good product, although I cannot confirm the lower price bracket. I've seen a PCI Digital Resolver Card for about $1800.

You might try looking at a company that already packages the motors with the Resolvers included. Can't seem to remember who, but I have a synchro motor from a swiss company that has the resolver already included (flight recorder tape deck motor); I believe it is a HP device, but I never could get the datasheet on this baby.

Other guys you might try for a ready solution is PC/104 (?), National Instruments, Linear Technology, Texas Instruments, ....

Regards,
Arno.

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A very messy proposition; the waveforms are quite ugly. There's a reason why the quality off-the-shelf S/D and R/D converters are so pricey.

A lot depends on how accurate, how fast, how cheap, and how rugged. Is this for a naval gun fire control system servo loop or for a home-brew back scratcher?

Unless you absolutely have to tap into the raw resolver output, you might consider coupling a driven unit to a more digital-friendly Gray code rotary encoder. For ultimate cheapness at the cost of relative vs absolute, drive the quadrature encoder from a salvaged PC mouse.

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