| 摘要 |
<P>PROBLEM TO BE SOLVED: To simplify a circuit for suppressing radio signal noise (radio noise), generated accompanying switching in an electric motor driving device for making an FET switched as a switching element provided in the energizing route of the electric motor by a pulse width modulation (PWM) signal and controlling the rotational speed of the electric motor, etc. <P>SOLUTION: A series circuit of a first capacitor 11 and a resistor 12 is connected so that the first capacitor 11 is on the gate side, and the resistor 12 is on the drain side, in between the gate and the drain of an FET 101. A second capacitor 13 is connected between the connection point of the first capacitor 11 and the resistor 12 and the terminal of the opposite side to the drain side of the electric motor 109. A CR filter circuit is formed between the gate and the drain of the first capacitor 11 and the resistor 12; and also a snubber circuit, connected to the electric motor 109 by the resistor 12 and the second capacitor 13 in parallel, is formed. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
