| 摘要 |
PURPOSE:To obtain two phases accurately shifted by 90 deg. only by adjusting an amplification degree, by obtaining three-phase signals from a rotary encoder to take out a square wave from one of three phases while amplifying the outputs of the other two phases and comparing both of them with each other to take out a square wave. CONSTITUTION:The three-phase sine wave signals R, S, T from a rotary encoder are applied to a signal processing circuit. A comparator 12 compares R-phase output with reference voltage RV to obtain a square wave A-phase signal. S-phase output is compared with the reference voltage RV by a differential amplifier 13 and the output of said amplifier is inputted to a reversal amplifier 14 to become sine wave output. T-phase output is compared with the reference voltage RV by a differential amplifier 16 and the difference between both of them is taken out to obtain T-phase sine wave output. The outputs of the amplifiers 14, 16 are inputted to a comparator 15 to obtain a square wave B-phase signal. The shift between the A- and B-phases can be accurately set to 90 deg. by changing an amplification degree through the adjustment of a variable resistor VR and these phases are processed to make it possible to obtain a rotary pulse.
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