Abstract:
풍력을 이용한 압전식 발전기는, 충전기를 포함하는 중심축부, 중심축부의 외주면에 결합되며, 각각 기설정된 면적을 갖는 압전 필름을 둘러싸도록 형성된 하나 이상의 압전 필름 지지 프레임, 및 압전 필름 지지 프레임에 의해 둘러싸이며, 압전 필름 지지 프레임의 일측부 및 중심축부 중 적어도 하나에 결합된 압전 필름을 포함하며, 압전 필름에 의하여 생성된 전기는 중심축부의 충전기로 전달된다.
Abstract:
An ultrasonic wave-based water level meter includes an ultrasonic sensor for outputting ultrasonic waves toward a first direction, and sensing the ultrasonic waves coming in from the first direction; and a reflector arranged to be separated from the ultrasonic sensor at a predetermined distance. The reflector reflects the ultrasonic waves output from the ultrasonic sensor toward a second direction which is intersectional to the first direction, and reflects ultrasonic waves coming in from the second direction after being reflected from the surface of water.
Abstract:
Disclosed is a piezoelectric stack transducer. A transducer part continuously stacks a plurality of piezoelectric transducers to output the maximum amplitude at different frequencies. A stack electrode part is formed on each of both sides of the piezoelectric transducers which are continuously stacked and generates a vibration by supplying an electric signal. At this time, each of the piezoelectric transducers includes a different diameter. According to the present invention, formed is the piezoelectric stack transducer which shows a constant amplitude (output) at various frequencies by enabling the piezoelectric transducer showing a different amplitude at each frequency according to a natural frequency to compensate the amplitude of the different transducer.