| 摘要 |
PROBLEM TO BE SOLVED: To simplify a circuit configuration and to reduce the load of an entire system by performing addition operation of a selected voltage and reducing a target voltage to be varied as compared with the number of phases to be controlled. SOLUTION: Output of operational amplifiers Q1 and Q2 of a motor is added by an addition amplifier Q9 and is compared with an output 2V ref of a reference voltage source Vx by a comparator Q6, and the output of operational amplifiers Q3 and Q4 is added by an addition amplifier 10 and is compared with the output 2Vref of the reference voltage source Vx by a comparator Q7. Then, one of the output of the operational amplifiers Q1, Q2, Q3, and Q4 is selected by a third selection circuit S3. However, the output of a D/A converter Q12 wit the output Vref of the reference voltage source Vx as the reference voltage is compared with a selected voltage with a comparator Q5, the output of four comparators Q5-Q8 is passed to a PWM signal generation circuit for generating a duty-controlled PWM pulse, and output elements Tr1, Tr2-Tr9, and Tr10 are controlled, and as a result changing of the setting of conditions is facilities. |
