| 摘要 |
PURPOSE:To generate a sawtooth wave that has a constant waveheight level at all times regardless of the length of sweep time, by producing a sawtooth wave having an inclination equal to the value obtained by dividing the waveheight level with the sweep time that is obtained through measurement. CONSTITUTION:A sweep input gate signal (a) is fed to a pulse width measuring circuit 41, and the pulse width T is measured by counting the clock signals supplied from a timing control circuit 45. Then an output signal (c) is obtained through a reverse proportion circuit 42, and the signal (c) has the digital quantity equivalent to A'/N (A': constant value and n: count number). A step signal producing circuit 43 adds the A'/n digital quantity up to (n) count number as soon as the next input gate signal arrives, and a digital signal which changes in steps is delivered. This digital signal is converted into an analog signal by a D/A converting circuit 44. Then the linearity obtained in a state of inclination is provided to the analog signal through a filter, an amplifier, etc. to obtain a sweep sawtooth wave. |
