| 摘要 |
PROBLEM TO BE SOLVED: To reduce a noise by switching the switching frequency of a PWM pulse by double random controlling. SOLUTION: A frequency deciding circuit 2 constitutes a frequency deciding means for random deciding the frequency of a switching signal. A primary random number generator circuit 1 generates a primary random number value for switching a frequency set value randomly decided by the circuit 2 at a random period. The circuit 1 randomly decides timing of designating the oscillating frequency for the circuit 2 according to the primary random number value. The circuit 2 is operated to impart the designated value of the random oscillating frequency to a triangular wave oscillator 3. COPYRIGHT: (C)2004,JPO
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