| 摘要 |
The invention relates to a frequency modulation switching circuit (1) for controlling a useful circuit (30), said switching circuit comprising an integrated component (10) provided with a saw tooth generator (11) for generating a saw tooth signal of a fixed frequency, that is connected to a first and a second connection (12,13) of the integrated component (10). A discreet resistance (14) is connected to the first connection (12) and a discreet charge accumulator (15) is connected to the second connection (13), the dimensioning of the resistance and the accumulator fixing the slope of the rising edge and the falling edge of the saw tooth signal, and thus the frequency, at a defined value. A current source (16) connected to the second connection (13) is used to adjust the duration of the charging process of the charge accumulator (15), and thus the rising edge of the saw tooth signal, by means of the production of a current, the current source (16) being formed independently of the integrated component (10). |
