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TIDA-RESOLVER-APPLICATIONS-REFERENCE-DESIGN: Resolver electrical zero position

Part Number: TIDA-RESOLVER-APPLICATIONS-REFERENCE-DESIGN
Other Parts Discussed in Thread: AMC1210, PGA411-Q1

Hi,

We are using a resolver for our axial type motor. 

Our customers requested for the following details

-position offset in degrees between the resolver's mechanical zero position and the machine's electrical zero position

- a specification of the procedure used to take the measurement.

Could you please guide me to get answers for the above questions. If there is any instrument to find the offset in degree that would also help us.

  • Hi Vikash,

    Welcome to our e2e Forum! I am sorry for the delay in getting back to you on this topic, everyone here has been on holiday. There is no direct provision in the AMC1210 to detect angular measurements. You would need to apply the SIN and COS winding's through one of our delta-sigma modulators to two of the filter inputs of the AMC1210. From there, you would need to process the SIN/COS values in software to determine the angular position of the motor. Here is an application note that describes how to use the internal signal generator function of the AMC1210 to generate the excitation signal for the resolver, which should help you as well:
    www.ti.com/.../sbaa144.pdf
  • Hi,
    Can I please know if PGA411-Q1 can be used to find the position offset in degree. ?

    Looking at your AMC1210EVM software the users guide state that the software can only be used in PC running windows XP. Not windows 7 or vista . If that's true then it's complicated to use the software.

    The below document looks useful. Can I please know if this helps to find the position offset in angles.

    www.ti.com/.../tidubi2a.pdf.

    www.ti.com/.../tiduc21a.pdf
  • Hi Vikash,

    the PGA411-Q1 is an highly integrated single-chip resolver to digital converter and provide the resolver mechanical position in a 12-bit or 10-bit digital representation, through SPI or parallel interface. Please refer to TIDA-00363 TI design for hardware design and test results.

    The zero position is with respect to the resolver's mechanical zero position. As you wrote there could be an offset between the motor's mechanical zero angle position and the resolver's mechanical zero angle position, depending how you mount it to the motor shaft. I write mechanical angle since the motor electrical angle depends on the pole pairs of the motor. For a single pole pair the electrical and mechanical angle are equal. For two or more pole pairs is scales accordingly.

    With the PGA411-Q1's digital output you'd simply subtract this offset for the digital output angle. If you don't know the offset, as simple method is to apply a zero voltage vector to the motor to stall it to it's zero position. Then you read the resolver angle. The difference is your mechanical offset if you have a single pole pair motor.

    Regards, Martin

     

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