| 摘要 |
PURPOSE:To simplify the change control of the amplitude and the period of a conversion signal by digitally setting the conversion ratio of a D/A converter by a conversion ratio setting device. CONSTITUTION:If only a signal S72 out of signals S71-S74 constituting a set signal S7 given from a control signal setting device 17 to the control terminal of a D/A converter 16 goes to the high level as shown in the right half of the figure and a control signal S6 given to the control terminal of a D/A converter 14 is increased by the D/A converter 16, the amplitude of a conversion signal S4 is reduced as shown in the right half of the figure because this amplitude is inversely proportional to the control signal S6 and this signal S6 is increased. As the result, the amplitude of a smoothed signal S5, namely, the amplitude of a function signal S5 is reduced as shown in the right half of the figure. Thus, the conversion ratio of the converter 14 is changed to easily control and change the amplitude of the smoothed signal as a square wave output signal. |
