| 摘要 |
PURPOSE:To obtain an echo sounder, the dynamic range of which is not restricted, with a simple configuration by producing a reception beat signal by means of a gate circuit, which is controlled by a transmission pulse, and BPF. CONSTITUTION:The voltage control oscillator 2 produces a square wave signal, which increases or decreases the synchronism for a fixed time, through the voltage scanning circuit 1, an ultrasonic pulse is transmitted to the object by the amplifier 3 and transmitter 4. On the other hand, the square wave signal is fed to the gate circuit as a control signal to control the turning operation of the gate circuit 7, and a beat signal, the frequency and amplitude of which are corresponding to both the distance between the device and the object and the intensity of echo from the object, by the reception pulse reflected by the object is produced by the BPF 8 without a complicated multiplier. Accordingly the sounder can be simplified in structure, the restriction on the dynamic range in using the multiplier can be eliminated to improve the sounding precision. |
