When we carry out open-sea fishing operations, or conduct surveys on marine fish populations, we will use a "detection helper" that is, fish finder, fish finder is generally located by sonar, based on the principle of sound wave transmission, it can be used to detect the contour, state, composition and size, location, size and so on of the fish under the water. So do you know how the power amplifier drives the transducer that is indispensable in a fish finder?aigtekAetna ElectronicsAnswers for you!
Techniques applied by fish detection institutes.
Underwater acoustic technology used in marine research and development includes echo detection, passive detection, underwater acoustic communication, acoustic releaser, underwater acoustic positioning, etc., and fish detection can use echo detection technology and fish finders, or passive sonar for fish trapping.
The fish echoes obtained by the fish finder can be used to roughly determine the location, extent and density of the fish. The transducer is the main component of the fish finder, which can convert the electronic signal into a sound pulse and transmit it to the water, when the sound wave encounters an obstacle in the process of propagating in the water, part of the sound signal is backscattered to the transducer, if the signal level exceeds the threshold selected by the user, it will be received by the transducer and converted into an electronic signal and transmitted to the control computer through the cable to generate an echo diagram. According to the interval time between receiving the target echo signal after the sound wave is transmitted and the propagation speed of the sound wave in the water, the position of the target can be measured, the strength and structure of the echo signal can be analyzed, and the target intensity, number and distribution of the target can be estimated.
Typical vertical fish finders are used to detect fish on the ground;Horizontal fish finders are mainly used to detect fish in the upper and middle pelagic layers. The common working frequency of the vertical fish finder is 20 200 kHz, and the depth of the fish detection can reach 1000 meters.
Similarly, passive sonar technology can also be used in fish detection or trapping, and the sound sources it hears can be divided into two categories: natural and man-made. Natural sound sources: Many animals in the ocean can also make sounds, so passive detection systems can be used to monitor the swimming characteristics of fish and judge the species of fish according to the characteristics of fish sounds, providing valuable data for marine fishing. In addition, the hydrophone system under the deep sea can also accurately measure the location of underwater volcanic eruptions and estimate their intensity. Anthropogenic sound sources: Fish are very sensitive to sound, and have likes and dislikes, so they can make sounds they like to trap them, and make sounds they don't like to hear to expel them;Acoustic fish traps and fish repellers made based on this principle have begun to be used in marine fishing. According to different purposes, a small acoustic beacon is tied to the fish body or incorporated into its stomach by using continuous, pulsed or other modulated signal sources, and tracked by passive sonar, which is very suitable for field research on the Xi of marine organisms.
About the principle of fish finders.
The fish finder can play a role, mainly relying on the ultrasonic transducer configured in it, first through the ultrasonic transducer to transmit relevant signals, and then through the transmission of air or water, the use of ultrasonic contact in the water and feedback back the signal can be processed by the internal processor, the specific situation under the water is displayed on the screen, so that anglers can roughly judge the relevant situation of the fish through this information, so as to increase the success rate.
Ultrasonic transducers, on the other hand, use the piezoelectric effect of piezoelectric ceramic sheets with the same resonant frequency between the two to convert electrical energy into mechanical vibration. Generally, ultrasonic waves are formed by ultrasonic generators, which are converted into mechanical vibrations through ultrasonic transducers, and then exported by ultrasonic devices and ultrasonic receiving devices to form ultrasonic waves. Therefore, as an energy conversion device, the role of the ultrasonic transducer is to convert the input electrical power into mechanical power (i.e., ultrasonic) and then transmit it, and it consumes a very small part of the power.
In this system, the underwater acoustic power amplifier is used to generate an excitation signal and provide ultrasonic energy to the ultrasonic transducer, and the excitation signal he generates is matched with the transducer impedance through the matching circuit after power amplification, so as to drive the transducer to work, that is, to provide a driving signal for the ultrasonic transducer, and the driving signal is converted into the required sound field after the ultrasonic transducer, and the electrical signal is converted into a mechanical vibration signal.
The principle of underwater acoustic power amplifier is that the signal generator first generates a signal of a specific frequency, and the excitation signal generated by the signal source drives the transducer to work after power amplification, and this specific frequency is the frequency of the transducer. Generally, the ultrasonic frequency used in ultrasonic equipment is tens of kHz, hundreds of kHz or several MHz, and with the continuous development of precision technology, the use area is gradually expanding.
ATA-L50 underwater acoustic power amplifier
Bandwidth: (-3db) 200hz 120khz
Voltage: 1200vrms
Power: 6500VA
Impedance: The output impedance matching is adjustable in multiple gears.
Display: LCD dynamic display of device status.
Protection: Overheat, overload protection.
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