Abstract: An amplitude calculation apparatus or an amplitude calculation program of an output signal of an encoder dividing a resurge waveform into a predetermined number of angle areas, presetting and storing coefficient ? of the A-phase and the coefficient ? of the B-phase corresponding to the divided angle areas, the coefficients being set so that ?A+?B approximates the radius of the theoretical resurge waveform, calculating the radius of the resurge waveform as ?A+?B, and making the calculated radius the amplitude of the output signal of the encoder or converting a phase angle ? of a quadrant n to a phase angle ?? of the quadrant 1, and calculating the radius of the resurge waveform as ?|A|+?|B|, whereby the circuit size of the apparatus for calculating the resurge radius from the output of the encoder is reduced and the processing time by software for calculating the resurge radius is shortened.

Abstract: In an encoder which is equipped with two detectors arranged on both sides of a rotating shaft in order to eliminate an eccentricity error, the mounting of the detectors is facilitated by making provisions so as to not cause a problem in the calculating of an average even if the detectors happen to be so mounted that the difference between the angular values calculated from the outputs of the respective detectors becomes equal to 180°. In an initialization process after power on, the difference ?? between the angular values ?1 and ?2 calculated from the signals output from the respective detectors is stored as an initial value. Position data ? is output by taking an average between ?3 and ?2, where ?3 is a value obtained by correcting ?1 by the initial difference ??.

Abstract: An amplitude calculation apparatus or an amplitude calculation program of an output signal of an encoder dividing a resurge waveform into a predetermined number of angle areas, presetting and storing coefficient ? of the A-phase and the coefficient ? of the B-phase corresponding to the divided angle areas, the coefficients being set so that ?A+?B approximates the radius of the theoretical resurge waveform, calculating the radius of the resurge waveform as ?A+?B, and making the calculated radius the amplitude of the output signal of the encoder or converting a phase angle ? of a quadrant n to a phase angle ?? of the quadrant 1, and calculating the radius of the resurge waveform as ?|A|+?|B|, whereby the circuit size of the apparatus for calculating the resurge radius from the output of the encoder is reduced and the processing time by software for calculating the resurge radius is shortened.

Abstract: An encoder sampling a first phase (A) signal and second phase (B) signal with phases differing from each other by about 90 degrees at the same timing, converting them from an analog to digital format, and detecting an angle signal based on the obtained digital signals, provided with offset detection circuits using a second phase A/D converted value (BD) of when a first phase A/D converted value (AD) is near a first value (XA) to find a second phase (B) offset value (Bofs), using a first phase A/D converted value (AD)of when a second phase A/D converted value (BD) is near a second value (XB) to find a first phase (A) offset value (Aofs), and using the currently found first offset value (Aofs) for the first value (XA) and the currently found second offset value (Bofs) for the second value (XB)when calculating the next first offset value (Aofs) and second offset value (Bofs) and a subtraction circuits using a first offset value (Aofs) and second offset value (Bofs) to correct offsets of the first phase signal an

Abstract: In an encoder which is equipped with two detectors arranged on both sides of a rotating shaft in order to eliminate an eccentricity error, the mounting of the detectors is facilitated by making provisions so as to not cause a problem in the calculating of an average even if the detectors happen to be so mounted that the difference between the angular values calculated from the outputs of the respective detectors becomes equal to 180°. In an initialization process after power on, the difference ?? between the angular values ?1 and ?2 calculated from the signals output from the respective detectors is stored as an initial value. Position data ? is output by taking an average between ?3 and ?2, where ?3 is a value obtained by correcting ?1 by the initial difference ??.

Abstract: The invention relates to a process for preparing prilled bisphenol A by granulation which comprises adding compounds soluble in molten bisphenol A, not affecting adversely the melt color of bisphenol A to any significant extent, and have a melting point of 60.degree. C. or more to bisphenol A and granulating and also to a process which comprises adding the reaction mother liquor or cyrstallization mother liquor produced in the manufacturing step of bisphenol A to bisphenol A or the adduct of bispheol A and phenol or a mixture of bispheol A and phenol, removing the phenol, and granulating. The processes yield prilled bispheol A which have high strength and resist powdering.