Patent ID: 6278388
Filing Date: 2001-08-21
Classification: H03M

Abstract:
A digital conversion method for an analog signal for obtaining a digital angle output (.phi.) from rotation detection signals [sin .theta..multidot.f(t) and cos .theta..multidot.f(t): where f(t) is an exciting component] detected by a rotation detector, wherein the rotation detection signals [sin .theta..multidot.f(t) and cos .theta..multidot.f(t)] are guided to a multiplier and mutually operated with sin .phi. and cos .phi. derived from the digital angle output (.phi.) to obtain [sin .theta..multidot.f(t).times.cos .phi.]-[cos .theta..multidot.f(t).times.sin .phi.]=sin(.theta.-.phi.).multidot.f(t) as a first output signal, and the first output signal sin(.theta.-.phi.).multidot.f(t) is converted into a digital signal by positive/negative sign determination performed by a comparator when the first output signal sin(.theta.-.phi.).multidot.f(t) is synchronously detected to remove the exciting component f(t) and to obtain a second output signal sin(.theta.-.phi.) as an error deviation .epsilon..