| 摘要 |
PURPOSE:To decrease noise around 10MHz caused by resonance generated when a switching device is turned off by providing a capacitor with small capacitance in the vicinity of two terminals of the switching device of an inverter circuit. CONSTITUTION:A voltage is produced due to inductance of a wiring loop when a transistor 211 is turned off. The voltage is restricted low by means of a capacitor 207 which is connected across a collector and an emitter of the transistor 211. The frequency of resonance which is the cause of noise generated due to the voltage is determined by means of an inductor 221 and the capacitor 207 of the loop. The resonant frequency which is the cause of noise is adequately varied by varying the capacitance of the capacitor 207. Noise around the initial resonant frequency 10MHz is decreased by adjusting a resonant frequency to the initial frequency with low noise level. |
