| 摘要 |
<p>There is provided an R/D converter which can make high speed response. When a sine-wave for excitation of a resolver has a positive (or negative) maximum value, an AD converter performs AD conversion of sine-wave output and cosine-wave output of the resolver and makes input to an FPGA. The FPGA calculates on the basis of the input data, and outputs an obtained digital value to a DA converter and the like. Since the FPGA calculate the rotor shaft angle, as compared with the prior art (R/D converter of a tracking system) for performing a kind of PLL control including a close loop made up of a demodulator circuit, a voltage controlled oscillator, and the like, it becomes possible to perform rotor shaft angle calculation at higher speed, and by this, the high speed response can be made. Since the rotor shaft angle is obtained through digital operation, a compensation circuit for temperature drift which has been required in the prior art becomes unnecessary, and by that, the total structure becomes simple, and the cost can be made low. <IMAGE></p> |
