Controlling existing motors with resolvers

It seems that Glentek makes servo drives that can take input from resolvers for commutation, and emulate a quadrature encoder for other uses.
I've sent them an RFQ.

there are DMC2 31025P for sale on eBay but they are no cheap. As an alternative the Copley Controls Xenus servo drive. they take resolver input but you would need to have look at the manual (manual is online) and determine if it does accommodate your particular resolver type.  

tommylight wrote:

 i have resolvers that do not work with 7i49,

your particular resolver type.  

How can I tell what type of resolver I have?

I've done a little research, and have found three types of devices that are sometimes called resolvers:

1. brushless resolvers
2. variable reluctance resolvers
3. sin/cos encoders

It appears that brushless and variable reluctance resolvers are excited and measured the same way and should be indistinguishable by electronic means, whereas sin/cos encoders are driven with DC and produce sin and cosine signals only when the rotor is turning, but static voltages when it is stationary.
 

Nope, Variable Reluctance resolvers require quite a bit more excitation drive, and not all resolver circuits can handle these. Tamagawa is a leading manufacturer of these, but they also make "brushless resolvers" which require MUCH less drive. In the data sheets, they sometimes state the excitation impedance as a complex number, something like 95 + 135j Ohms at some frequency. The higher these numbers, the less drive current the resolver requires. Common brands of brushless resolvers seen on older equipment are Singer-Kearfott and Harowe Controls.
Sin/Cos encoders are not magnetic devices, but often optical linear scales (can also be rotary) where the raw optical signal is brought out, either as a voltage or a current. The reason for this is interpolator boxes can be attached to increase the encoder resolution. Back in the "old days" linear scales often had native resolution of 100 lines per inch or so, so interpolation was required to get proper machine accuracy. Nowadays, high-resolution optical gratings can be made easily, so this stuff is rarely seen today.
Jon

I think that Granite Devices drives handle resolvers, but the current drive (IONI) only handles 700W. (you need at least twice that)
The older "Argon" drive might fit the bill, though it's a bit down on power compared to the existing drives.
granitedevices.com/oldsite/digital-servo-drive-argon
Lists the following feedback sources:
Incremental encoder
• Analog Sin/Cos encoder
• Resolver/synchro
• Serial SSI & BiSS (upcoming feature)
• Tachogenerator
• Hall sensors

What is the feedback system used for axis position? Are there separate scales, or does that rely on the resolvers on the motors too?

STMBL would work, but doesn't fit your "industrial" and "don't want to build it myself" criteria. (though see the thread about a new STMBL on this forum.)