Enhance resolver with configurable excitation, interpolation of up to 16-bits

Used In:

  • Ascertaining absolute position (one resolver pole pair)
  • Systems used in harsh environments

When using a resolver, the drive sends an excitation signal with amplitude of 10V, and a transfer ratio of 0.5 between resolver output and input.

The figure above displays the signals over time in the constant position of 0°. The ratio of the amplitude between the Cos and Ref signals is 0.5 (transfer ratio).

To enhance resolver performance, the drive includes:

  • Automatic excitation signal time delay for best signal sampling:
  • Automatic correction of amplitude mismatch, phase mismatch and signal offset
  • Protection for exceeding high or low limits of signal amplitude:

Elmo drives support programmable reference frequency as follows:

1/(2*Ts*N), N=1/2,1, 2, 4
where Ts = sample time in microseconds

A special commutation method can also be used with the resolver, in which each electrical feedback cycle contains a whole number of electrical motor cycles.

 Design Features

  • Provides internal interpolation of up to 65536 times (16-bits)
  • Tuner automatically calibrates and compensates for feedback inaccuracies
  • Tuner automatically calibrates the excitation signal delay for best signal sampling
  • Configurable resolver excitation signal frequency
  • Tuner automatically finds the phase offset for a commutation