| 摘要 |
PURPOSE:To enable easy recognition of the result of measurement by a method wherein a time required for receiving emitted ultrasonic waves is converted into a period wherein an intermittent sound having an audio frequency is repeated. CONSTITUTION:Ultrasonic waves are emitted from an oscillator 4 for transmission by the output pulses of a one-shot pulse generating circuit 9, while a bistable multivibrator 18 is set. The ultrasonic waves received by an oscillator 5 for reception are given as reset pulses to the bistable multivibrator 18 through the intermediary of an ultrasonic wave receiver 2. The output of the bistable multivibrator 18 is given to a load 6 of a buzzer or the like via a pulse width- voltage transducing circuit 17, a voltage-frequency transducing circuit 16 and a monostable multivibrator 15, and thereby an audio-frequency sound having a tone color corresponding to the distance of measurement is generated. |
