| 摘要 |
PURPOSE:To suppress the noise of an automotive motor by composing an RC circuit in wirings which connect a switching element to a duty controller. CONSTITUTION:A comparator 22 of a duty controller 15 and transistors 23F, 23R of switching circuits 14F, 14R are respectively connected via coaxial cables 29F, 29R having core wirings 30F, 30R and coated wirings 31F, 31R. The cables 29F, 29R respectively connect via the core wirings 30F, 30R the comparator 22 to the transistors 23F, 23R, the wirings 31F, 31R are electrically grounded, and electrostatic capacity C0 is provided between the wirings 30F, 30R and the wirings 31F, 31R. A resistor 32 having the prescribed resistance value R0 is interposed in series between the wirings 30F, 30R and the comparator 22, and the resistor 32 forms an Rc circuit together with the cables 29F, 29R having electrostatic capacity C0. |
