Homemade mini-echo sounder on an Atmel ATMega8L microcontroller and LCD from a nokia3310 mobile phone. How to make an echo sounder from a smartphone Homemade echo sounder for fishing diagram

An electronic echo sounder can be useful for a wide variety of underwater activities - not just fishing.
The echo sounder can be manufactured in two versions: with depth measurement limits of up to 9.9 m (its display contains two luminescent indicators) and 59.9 m (three indicators).
Their other characteristics are the same:
instrumental error - no more than ±0.1 m,
operating frequency - 170...240 kHz (depending on the resonant frequency of the emitter),
pulse power - 2.5 W.
The ultrasonic emitter is also an echo signal receiver - a barium titanate plate with a diameter of 40 and a thickness of 10 mm.
The power source for echo sounders is a Corundum battery.
Current consumption is no more than 19 and 25 mA (in echo sounders for shallow and deep depths, respectively).
Dimensions of echo sounders - 175x75x45 mm, weight - 0.4 kg.

Schematic diagram of an echolocator

The G1 clock generator controls the interaction of the device components and ensures its operation in automatic mode. The short (0.1 s) rectangular pulses generated by it are repeated every 10 s. With their front, these pulses set the digital counter PC1 to the zero state and close the receiver A2, making it insensitive to signals while the transmitter is operating.

The falling clock pulse triggers the transmitter A1 and the emitter BQ1 emits a short (40 μs) ultrasonic probing pulse in the direction of the bottom. At the same time, the electronic key S1 opens and oscillations of the reference frequency from the generator G2 are sent to the counter PC1.

At the end of the transmitter operation, the A2 receiver opens and acquires normal sensitivity. The echo signal reflected from the bottom is received by the same BQ1 and closes the key S1. The measurement is completed, the measured depth is displayed on the indicators of the PC1 counter.
Depth calculation is simple : at a speed of sound propagation in water of 1500 m/s, in 1/7500 s the front of the signal traveling a double path will move by 0.2 m; and, accordingly, the lowest unit on the meter display will correspond to a depth of 0.1 m.

The next clock pulse will again transfer the counter PC1 to the zero state and the process will repeat.

The schematic diagram of an echo sounder with a depth measurement limit of 59.9 m is shown in Fig. 2.

Its transmitter, self-excited at the frequency of the ultrasonic emitter BQ1, is made using transistors VT8, VT9. Turning the transmitter on and off is controlled by a modulator - a standby monostable (VT11, VT12, etc.), which supplies power to the transmitter through its switch (VT10) for 40 μs.

Transistors VT1, VT2 in the receiver amplify the echo signal received by the piezoelectric element BQ1, transistor VT3 detects them, and transistor VT4 amplifies the detected signal. A single-vibrator is assembled on transistors VT5, VT6, ensuring constancy of the parameters of the output pulses and the sensitivity threshold of the receiver. The receiver is protected from direct influence of transmitter pulses by a diode limiter (R1, VD1, VD2).

The digital part of the echo sounder is assembled on DD1-DD4 microcircuits. It includes a key (DD1.1) controlled by an RS trigger (DD1.3, DD1.4). The counting start pulse comes to the trigger from the transmitter modulator through transistor VT16, the end pulse comes from the receiver output through transistor VT15.

The pulse generator of standard frequency (7500 Hz) is assembled on the DD1.2 element. By circuit R33, L1 it is put into linear amplifier mode, which creates conditions for its excitation at a frequency depending on the parameters of circuit L1 C 18. The generator is brought to exactly the frequency of 7500 Hz by adjusting L1.

The reference frequency signal is fed through the switch to a three-digit counter DD2-DD4. It is set to the zero state by the edge of the clock pulse supplied through the VD4 diode to the R-inputs of these microcircuits.

The clock generator is assembled on transistors VT13, VT14. The pulse repetition rate depends on the time constant R28-C15.

The filaments of the luminescent indicators HG1-HG3 are powered by a voltage converter made of transistors VT17, VT18 and transformer T2.

Button SB1 (“Control”) is used to check the functionality of the device. When you press it on the VT15 key, a closing impulse is received and some random number appears on the echo sounder display. After some time, the clock pulse will restart the echo sounder, and if it is working properly, the number 88.8 will appear on the display.

All resistors in the echo sounder are MLT type, capacitors are KLS, KTK and K53-1. Transistors KT312V and GT402I can be replaced with any other of these series, MP42B - with MP25, KT315G - with KT315V. Chips of the K176 series can be replaced with equivalent ones from the K561 series. If the echo sounder is intended to be used at depths of up to 10 m, the DD4 chip and the HG3 indicator do not need to be installed.

Transformer T2 is made on a ferrite (3000NM) ring of standard size K16x 10x4.5. Winding I contains 2x180 turns of PEV-2 0.12 wire, winding II - 16 turns of PEV-2 0.39 wire.

Coil L1 (1500 turns of PEV-2 0.07 wire) is wound between the cheeks on a frame with a diameter of 6 mm. The diameter of the cheeks is 15, the distance between them is 9 mm. The trimmer is made of carbonyl iron (from the armored magnetic circuit SB-1a).

Thin leads are soldered to the silvered planes of the emitter plate using Wood's alloy. The emitter is assembled in an aluminum cup with a diameter of 45...50 mm (the bottom part of the oxide capacitor housing). Its height - 23...25 mm - is specified during assembly. In the center of the bottom of the glass, a hole is drilled for a fitting through which a coaxial cable 1...1.25 m long will be routed, connecting the ultrasonic head with the electronic part of the echo sounder. The emitter plate is glued with 88-N glue to a disc made of soft microporous rubber 10 mm thick. During installation, the cable braid is soldered to the fitting, the central conductor is soldered to the terminal of the lining glued to the rubber disk, and the terminal of the other emitter plating is to the cable braid. The emitter assembled in this way is pushed into the glass. The surface of the emitter plate should be 2 mm below the edge of the glass. The glass is fixed strictly vertically and filled to the edge with epoxy resin. After it is installed, the end of the emitter is sanded with fine-grained sandpaper until a smooth flat surface is obtained. The mating part of connector X1 is soldered to the free end of the coaxial cable.

Setting up an echo sounder

To set up an echo sounder you will need an oscilloscope and a digital frequency meter. After turning on the power, check the functionality of the counting device: if it is working properly, then the indicators should display the number 88.8.

The operation of the transmitter is checked with an oscilloscope operating in standby sweep mode. It is connected to winding II of transformer T1. With the arrival of each clock pulse, a radio frequency pulse should appear on the oscilloscope screen. By adjusting transformer T1 (roughly by selecting the capacitance of capacitor C 10), its maximum amplitude is achieved. The amplitude of the radio pulse on the piezo emitter must be at least 70 V.

To set up the reference frequency generator, you will need a frequency meter. It is connected through a resistor with a resistance of 5.1 kOhm to the output (pin 4) of element DD1.2 and, by changing the position of the trimmer in coil L1 (roughly by changing the capacitance of capacitor C18), the required 7500 Hz is set.

The receiver and modulator are adjusted using echo signals. To do this, the emitter is attached with a rubber band to the end wall of a plastic box measuring 300x100x100 mm (to eliminate the air gap, this place is lubricated with technical petroleum jelly). Then the box is filled with water, the VD3 diode is removed from the receiver and an oscilloscope is connected to the receiver output. The criterion for the correct setting of the receiver, modulator and the quality of the ultrasonic emitter is the number of echo signals observed on the screen, resulting from multiple reflections of the ultrasonic pulse from the end walls (spaced 300 mm apart) of the box. To increase the visible number of pulses, select resistors R2 and R7 in the receiver, capacitor C 13 in the modulator, and adjust transformer T1.

Having returned the VD3 diode to its place, we begin to adjust the turn-on delay of the receiver. It depends on the resistance of resistor R18. This resistor is replaced with a variable resistor of 10 kOhm and its value is found at which the first two echo signals disappear on the oscilloscope screen. This is the resistance that resistor R18 should have. After setup, the number of echo signals on the oscilloscope screen should be at least 20.

To measure the depth of a reservoir, the lower part of the ultrasonic head is immersed in water by 10...20 mm. It is better to have a special float for it.

Currently, echo sounders for fishing are very popular among fishermen and athletes.
What gives echo sounder fisherman?
The answer to this question seems to be quite simple - echo sounder searches and finds fish, and this is its main purpose. However, the unambiguity of this answer may seem absolutely fair only to a novice fisherman. Every more or less competent fisherman knows that fish are not distributed evenly throughout the space of reservoirs, but gather in certain places determined by the bottom topography, sudden changes in depth and even temperature differences between layers of water. Snags, stones, holes, and vegetation may be of interest. In other words, the fish not only looks for where it is deeper, but also where it is better for it to spend the night, hunt, camouflage, and feed. Therefore, the primary task of an echo sounder is to determine the depth of a reservoir and study the bottom topography.
A block diagram that explains the structure and operation of the echo sounder is shown in Fig. 1. Clock generator G1 controls the interaction of the device components and ensures its operation in automatic mode. The short (0.1 s) rectangular pulses of positive polarity generated by it are repeated every 10 s.

With their front, these pulses set the digital counter PC1 to the zero state and close the receiver A2, making it insensitive to signals while the transmitter is operating. The falling clock pulse triggers the transmitter A1, and the emitter-sensor BQ1 emits a short (40 μs) ultrasonic probing pulse in the direction of the bottom. At the same time, the electronic key S1 opens, and oscillations of a reference frequency of 7500 Hz from the generator G2 are sent to the digital counter PC1.

At the end of the transmitter operation, the A2 receiver opens and acquires normal sensitivity. The echo signal reflected from the bottom is received by sensor BQ1 and, after amplification in the receiver, closes key S1. The measurement is completed and the PC1 counter indicators display the measured depth. The next clock pulse again resets the PC1 counter to zero, and the process repeats.

Fundamental echo sounder diagram with a depth measurement limit of up to 59.9 m is shown in Fig. 2. Its transmitter is a push-pull generator on transistors VT8, VT9 with transformer T1 tuned to the operating frequency. The positive feedback necessary for self-excitation of the generator is created by circuits R19C9 and R20C11." The generator generates pulses with a duration of 40 μs with radio frequency filling. The operation of the transmitter is controlled by a modulator consisting of a one-shot on transistors VT11, VT12, which generates a modulating pulse with a duration of 40 μs, and an amplifier on transistor VT10 The modulator operates in standby mode, triggering clock pulses are supplied through capacitor C14.

Echo sounder receiver assembled using a direct amplification circuit. Transistors VT1, VT2 amplify the echo signal received by the emitter-sensor BQ1, transistor VT3 is used in the amplitude detector, transistor VT4 amplifies the detected signal. A single-vibrator is assembled on transistors VT5, VT6, ensuring constancy of the parameters of the output pulses and the sensitivity threshold of the receiver. The receiver is protected from the transmitter pulse by a diode limiter (VD1, VD2) and resistor R1.

The receiver uses forced switching off of the receiver's monostable using transistor VT7. A positive clock pulse is sent to its base through diode VD3 and charges capacitor C8. When opening, transistor VT7 connects the base of transistor VT5 of the receiver monostable with the positive power wire, thereby preventing the possibility of it being triggered by incoming pulses. At the end of the clock pulse, capacitor C8 is discharged through resistor R18, transistor VT7 gradually closes, and the monostable receiver acquires normal sensitivity. The digital part of the echo sounder is assembled on DD1-DD4 microcircuits. It includes a key on element DD1.1, controlled by an RS trigger on elements DD1.3, DD1.4. The counting start pulse comes to the trigger from the transmitter modulator through transistor VT16, the end pulse comes from the receiver output through transistor VT15.

A pulse generator with an exemplary repetition frequency (7500 Hz) is assembled on the DD1.2 element. Resistor R33 and coil L1 form a negative feedback circuit that brings the element to the linear portion of the characteristic. This creates conditions for self-excitation at a frequency determined by the parameters of the L1C18 circuit. The generator is tuned exactly to a given frequency using a coil trimmer.

The reference frequency signal is fed through the switch to a three-digit counter DD2-DD4. It is set to the zero state by the edge of the clock pulse supplied through the diode VD4 to the inputs R of the microcircuits.

The clock generator that controls the operation of the echo sounder is assembled using transistors of different structures VT13, VT14. The pulse repetition rate is determined by the time constant of the R28C15 circuit.

The cathodes of the HG1-HG3 indicators are powered by a generator using transistors VT17, VT18.

Button SB1 ("Control") is used to check the functionality of the device. When you press it, the VT15 key receives a closing pulse and the echo sounder indicators display a random number. After some time, a clock pulse switches the counter, and the indicators should display the number 888, which indicates that the echo sounder is working.

The echo sounder is mounted in a box glued together from impact-resistant polystyrene. Most of the parts are placed on three printed circuit boards made of foil-coated fiberglass laminate with a thickness of 1.5 mm. On one of them (Fig. 3) a transmitter is mounted, on the other (Fig. 4) a receiver, on the third (Fig. 5) the digital part of the echo sounder. The boards are mounted on a duralumin plate measuring 172x72 mm, inserted into the lid of the box. In the plate and On the cover, holes were drilled for the power switch Q1 (MT-1), the SB1 button (KM1-1) and the VR-74-F socket of the coaxial connector XI, and a window for digital indicators was cut out.

The echo sounder uses MLT resistors, KLS, KTK and K53-1 capacitors. Transistors KT312V and GT402I can be replaced with any other transistors of these series, MP42B with MP25, KT315G with KT315V. Microcircuits of the K176 series are interchangeable with the corresponding analogues of the K561 series; instead of the K176IEZ (DD4) microcircuit, you can use K176IE4. If the echo sounder will be used at a depth of no more than 10 m, the DD4 counter and the HG3 indicator do not need to be installed.

The windings of transformer T1 are wound with PELSHO 0.15 wire on a frame with a diameter of 8 mm with a ferrite (600NN) trimmer with a diameter of 6 mm. Winding length - 20 mm. Winding I contains 80 turns tapped from the middle, winding II contains 160 turns. Transformer T2 is made on a ferrite (3000NM) ring of standard size K16X10X4.5. Winding I contains 2X 180 turns of PEV-2 wire, 0.12, winding 11-16 turns of PEV-2 wire, 0.39. Coil L1 (1500 turns of PEV-2 0.07 wire) is wound between the cheeks on a frame with a diameter of 6 mm made of organic glass. The diameter of the cheeks is 15, the distance between them is 9 mm. The trimmer is from the SB-1a armored magnetic circuit made of carbonyl iron.

The ultrasonic emitter-sensor of the echo sounder is made on the basis of a round plate with a diameter of 40 and a thickness of 10 mm made of barium titanate. Thin (0.2 mm in diameter) lead conductors are soldered to its silver-plated planes using Wood's alloy. The sensor is assembled in an aluminum cup from an oxide capacitor with a diameter of 45...50 mm (height - 23...25 mm - specified during assembly). In the center of the bottom of the glass, a hole is drilled for a fitting through which a coaxial cable (RK-75-4-16, length 1...2.5 m) will enter, connecting the sensor to the echo sounder. The sensor plate is glued with 88-N glue to a disk made of soft microporous rubber 10 mm thick.

During installation, the cable braid is soldered to the fitting, the central conductor is soldered to the terminal of the sensor lining glued to the rubber disk, and the terminal of the other lining is to the cable braid. After this, the disk with the plate is pushed into the glass, passing the cable into the opening of the fitting, and the fitting is secured with a nut. The surface of the titanate plate should be recessed into the glass 2 mm below its edge. The glass is fixed strictly vertically and filled to the edge with epoxy resin. After the resin has cured, the surface of the sensor is sanded with fine-grit sandpaper until a smooth surface is obtained. The mating part of connector XI is soldered to the free end of the cable.

To set up an echo sounder, you need an oscilloscope, a digital frequency meter and a 9 V power supply. After turning on the power, check the functionality of the counting device: if it is working properly, the indicators should display the number 88.8. When you press the SB1 button, a random number should appear, which, with the arrival of the next clock pulse, should again be replaced by the number 88.8.

Next, the transmitter is set up. To do this, a sensor is connected to the echo sounder, and an oscilloscope operating in the standby sweep mode is connected to winding 11 of transformer T1. With the arrival of each clock pulse, a pulse with radio frequency filling should appear on the oscilloscope screen. By adjusting transformer T1 (if necessary, select capacitor C10) the maximum pulse amplitude is achieved, which should be at least 70 V.

The next stage is the establishment of a pulse generator of exemplary frequency. To do this, the frequency meter is connected through a resistor with a resistance of 5.1 kOhm to pin 4 of the DD1 microcircuit. The generator is tuned to a frequency of 7500 Hz by adjusting coil L1. If the trimmer takes a position far from the average, select capacitor C18.

The receiver (as well as the modulator) is best tuned using echo signals, as described in [I]. To do this, the sensor is attached with a rubber band to the end wall of a plastic box measuring 300x100x100 mm (in order to eliminate the air gap between the sensor and the wall, it is lubricated with technical petroleum jelly). Then the box is filled with water, the VD3 diode is removed from the receiver and an oscilloscope is connected to the receiver output. The criterion for the correct configuration of the receiver, transmitter modulator, as well as the quality of the ultrasonic sensor is the number of echo signals observed on the screen, resulting from multiple reflections of the ultrasonic pulse from the end walls of the box. To increase the visible number of pulses, select resistors R2 and R7 in the receiver, capacitor C13 in the transmitter modulator and change the position of the transformer trimmer T1.

To adjust the receiver turn-on delay device, solder in the VD3 diode, replace the R18 resistor with a variable one (resistance 10 kOhm) and use it to make the first two echo signals disappear on the oscilloscope screen. Having measured the resistance of the introduced part of the variable resistor, it is replaced with a constant one of the same resistance. After setup, the number of echo signals on the oscilloscope screen should be at least 20.

To measure the depth of a reservoir, it is best to attach the sensor to a float so that its lower part is immersed in water by 10...20 mm. You can attach the sensor to a pole, with which it is immersed in water briefly while measuring depth. When using an echo sounder in a flat-bottomed aluminum boat to measure shallow depths (up to 2 m), the transducer can be glued to the bottom inside the boat.

It should be noted that on sunny days the brightness of the digital indicators may not be sufficient. It can be increased by replacing the Corundum (Krona) battery with a power source with a slightly higher voltage, for example, a battery made up of eight D-0.25 batteries (this will not require any changes to the circuit or design of the device).

A little theory

How do we see fish using an echo sounder?
Sound waves from an echo sounder are reflected from physical moving objects (i.e. places where the speed of sound changes). Fish are mostly made of water, but the difference between the speed of sound in the water and in the gas that is in the fish's air bladder is so great that it allows the sound to be reflected and returned. The air bubble allows the fish to stay at a certain depth without the help of fins (submarines are built on the same principle). Therefore, with the help of an echo sounder, we “see” not the fish itself, but its air bubble, which, by and large, makes no difference to the fisherman. If there is a bubble, then there is a fish. But you still need to know that each gas-filled air bubble, like the air flow in an organ pipe, has its own natural frequency. When sound waves of the same frequency reach the bubble, it resonates, and the resonance frequency is several times higher than the frequency of the wave itself. Therefore, the “goal” appears larger than it actually is.

Looking deeper, the tone of the air bubbles' resonance is determined by the water pressure, the size and shape of the bubble, and the physical obstructions within the fish itself.
These factors change as the fish moves vertically through different depths.

How does sonar show fish?
The picture shows a typical “nail oval” (arc), formed by the pattern of movement of one fish from the center to the corners, or the angle of a cone when the boat is stationary. The same effect can be created if the boat is moving and the fish is stationary. But you'll rarely see that perfect arc because the fish you're looking for is always moving outside the arc, and not necessarily level or centered. The larger the nail oval, the bigger the fish, right? No, not necessarily.

Fish of the same size swimming in the center of the arc towards the surface may remain in the arc for a short time and therefore produce a small print. If the same fish presses to the bottom and passes through the center of the arc, it will enter the target zone for a longer period of time and give a larger signal. Generally speaking, a fish will appear smaller the closer it is to the transducer and larger the further it is away from it.
This is exactly the opposite of what our eyes see in sunlight. Variations in this ideal “nail oval” can occur for a number of reasons. Fish swim up and down, they pass through the outer edges of the arc at irregular angles, the boat moves either slowly or quickly, the fish may be so close to the bottom that it is partly in the "dead zone". For example, you will find that a school of the desired fish , located in a close cluster in a horizontal layer, forms a large arc, but with angles that differ little from the mark of one fish. So, you will see many variations of this "oval nail" shape, but remember that it is a common display that is returned by the fish.
One mistake common to all fish finders that few fishermen know or even think about is that everything APPEARS as if it is under the boat when in fact it is not.

The picture shows what actually happens underwater with our sound cone and our impression of it based on a flashing scale or 2D image.

The picture shows how all echo sounders give an error in reading the fish located between the boat and the bottom.
This is due to the fact that the device tries to line up all the fish found within the cone in one straight line, which convinces us that the fish is directly under the bottom of the boat.
The figure also shows us what happens when two (or more) fish are detected at the same distance (from the transducer) when in fact they are at different ends of the cone.
All of them are marked by the echo sounder as being at the same distance, and therefore are shown as one fish.
Fishing with an echo sounder very interesting, and also adds confidence and, as a result, a catch.

Do-it-yourself fisherman's echo sounder

Currently, echo sounders for fishing are very popular among fishermen and athletes.
What gives echo sounder fisherman?
The answer to this question seems to be very simple - echo sounder searches and finds fish, and this is its main purpose. But the unambiguity of this answer may seem completely fair only to a novice fisherman. Every more or less competent fisherman knows that fish are not distributed moderately throughout the water bodies, but gather in certain places determined by the bottom topography, sudden changes in depth and even temperature differences between layers of water. Enthusiasm can be represented by snags, pebbles, holes, and vegetation. In other words, the fish not only looks for where it is deeper, but also where it is better for it to spend the night, hunt, camouflage, and feed. Therefore, the main task of an echo sounder is to determine the depth of a reservoir and study the bottom topography.
A block diagram that explains the structure and operation of the echo sounder is shown in Fig. 1. Clock generator G1 controls the interaction of device nodes and ensures its operation in automatic mode. The short (0.1 s) rectangular pulses of positive polarity generated by it are repeated every 10 s.

With their front, these pulses set the digital counter PC1 to the zero state and close the receiver A2, making it insensitive to signals while the transmitter is operating. The falling clock pulse triggers the transmitter A1, and the emitter-sensor BQ1 emits a small (40 μs) ultrasonic probing pulse in the direction of the bottom. The electric switch S1 immediately opens, and oscillations of an approximate frequency of 7500 Hz from the generator G2 are sent to the digital counter PC1.

Principle echo sounder diagram with a depth measurement limit of up to 59.9 m is shown in Fig. 2. Its transmitter is a push-pull generator on transistors VT8, VT9 with transformer T1 tuned to the operating frequency. The positive feedback required for self-excitation of the generator is made by circuits R19C9 and R20C11. The generator generates pulses of 40 μs duration with radio frequency content. The operation of the transmitter is controlled by a modulator consisting of a single-vibrator on transistors VT11, VT12, which generates a modulating pulse with a duration of 40 μs, and an amplifier on transistor VT10. The modulator operates in standby mode, the triggering clock pulses arrive through capacitor C14.

Echo sounder receiver assembled using a direct amplification circuit. Transistors VT1, VT2 amplify the echo signal received by the emitter-sensor BQ1, transistor VT3 is used in the amplitude sensor, transistor VT4 increases the detected signal. A single-vibrator is assembled on transistors VT5, VT6, ensuring constant characteristics of the output pulses and the sensitivity threshold of the receiver. The receiver is protected from the transmitter pulse by a diode limiter (VD1, VD2) and resistor R1.

The receiver uses forced switching off of the receiver's monostable using transistor VT7. A positive signal is supplied to its base through the VD3 diode. clock pulse and charges capacitor C8. When opening, transistor VT7 connects the base of transistor VT5 of the receiver monostable with the positive power wire, thereby preventing the possibility of it being triggered by incoming pulses. At the end clock pulse capacitor C8 is discharged through resistor R18, transistor VT7 is uniformly turned off, and the receiver’s monostable acquires normal sensitivity. The digital part of the echo sounder is assembled on DD1-DD4 microcircuits. It includes a key on element DD1.1, controlled by an RS trigger on elements DD1.3, DD1.4. The counting start pulse comes to the trigger from the transmitter modulator through transistor VT16, the end pulse comes from the receiver output through transistor VT15.

A pulse generator with an approximate repetition frequency (7500 Hz) is assembled on the DD1.2 element. Resistor R33 and coil L1 make up a negative feedback circuit that brings the element to the linear section of the property. This creates conditions for self-excitation at a frequency determined by the parameters of the L1C18 circuit. The generator is tuned exactly to a given frequency using a coil trimmer.

Read also

The approximate frequency signal is sent through the key to a three-digit counter DD2-DD4. It is set to the zero state by the edge of the clock pulse arriving through the VD4 diode to the R inputs of the microcircuits.

The cathodes of the HG1-HG3 indicators are powered by a generator using transistors VT17, VT18.

Button SB1 (“Control”) is used to check the functionality of the device. When you press it, the VT15 key receives a closing pulse and the echo sounder indicators display a random number. After some time, a clock pulse switches the counter, and the indicators should display the number 888, which indicates that the echo sounder is working properly.

Cheap wireless echo sounder from Aliexpress for fishing.

Echo sounder Program title: FishFinder (Erchang Fish Finder) Others echo sounders: .

Echo sounder on Arduino

The echo sounder uses MLT resistors, KLS, KTK and K53-1 capacitors. Transistors KT312V and GT402I can be replaced with any other transistors of these series, MP42B with MP25, KT315G with KT315V. Microcircuits of the K176 series are interchangeable with the corresponding analogues of the K561 series; instead of the K176IEZ (DD4) microcircuit, you can use K176IE4. If echo sounder will be used at a depth of no more than 10 m, the DD4 counter and the HG3 indicator need not be installed.

The ultrasonic emitter-sensor of the echo sounder is made on the basis of a round plate with a diameter of 40 and a thickness of 10 mm made of barium titanate. Thin (0.2 mm in diameter) lead conductors are soldered to its silver-plated planes using Wood's alloy. The sensor is assembled in an aluminum cup from an oxide capacitor with a diameter of 45.50 mm (height - 23.25 mm - specified during assembly). In the center of the bottom of the glass, a hole is drilled for a fitting through which a coaxial cable (RK-75-4-16, length 1.2.5 m) will enter, connecting the sensor to the echo sounder. The sensor plate is glued with 88-N glue to a disk made of soft microporous rubber 10 mm thick.

During installation, the cable braid is soldered to the fitting, the central conductor is soldered to the terminal of the sensor plate glued to the rubber disk, and the terminal of the other plate is soldered to the cable braid. After this, the disk with the plate is pushed into the glass, passing the cable into the opening of the fitting, and the fitting is secured with a nut. The surface of the titanate plate should be recessed into the glass 2 mm below its edge. The glass is fixed strictly vertically and filled to the edge with epoxy resin. After the resin has cured, the surface of the sensor is sanded with fine-grit sandpaper until a smooth surface is obtained. The mating part of connector XI is soldered to the free end of the cable.

Read also

To measure the depth of a reservoir, it is best to attach the sensor to a float so that its lower part is immersed in water by 10.20 mm. You can attach the sensor to a pole, with which it is immersed in water briefly while measuring depth. When using an echo sounder in a flat-bottomed aluminum boat to measure shallow depths (up to 2 m), the transducer can be glued to the bottom inside the boat.

The fishing process is becoming more technologically advanced and efficient. This is facilitated by the emergence of new devices that expand the capabilities of fishermen. A fish finder is one of the most common gadgets used in this field. Sensitive sensors scan the underwater space, providing the user with the necessary information through the screen. Today, an echo sounder for a smartphone on Android is becoming increasingly popular, the workflow of which only requires connecting a sensor. All recorded information is displayed on a mobile device without additional electronic devices.

What is a smartphone echo sounder?

This is a type of portable sonar sensor that can be attached to a fishing line or a special rope. The traditional design of the device is the shape of a ball into which the transducer is integrated. You can only use an echo sounder with a smartphone from the shore, since on a boat, especially while moving, it will be impossible to ensure its reliable fixation. There are models for iOS and Android operating systems. In this case, the second option is considered, but increasingly manufacturers provide support for both systems.

It is important to emphasize the absence of wires in the communication system. If stationary transom models have a cable connection to the display, then an echo sounder that works with a smartphone transmits a signal via Bluetooth or Wi-Fi. There are also modifications with radio modules.

Operating principle of the device

Despite the significant differences between portable wireless and stationary models, all echo sounders operate based on the emission of pulses, which are processed and presented to the user in a convenient form. The same smartphone, using a special application, will graphically reflect the bottom topography, show the depth and activity of fish - the specific set of information depends on the model. The main means of echolocation is the aforementioned transducer. This is an emitter sensor that sends signals to the bottom surface and receives reflected waves. During operation, the echo sounder and the smartphone can change interaction parameters depending on the conditions. In particular, the user can initially configure the communication properties himself, but high-tech models are able to automatically adjust, for example, the frequency of sending pulses. After the information appears on the smartphone screen, the user makes certain decisions to change fishing tactics. Such devices allow you to search for the most favorable places for fishing.

Power supply system

The lack of wires causes one of the main disadvantages of such sonars. The fact is that fishing is a long process, and the autonomy of wireless electronics is always limited to a few hours. The sensors are equipped with batteries with an average capacity of 500-1000 mAh. Although in standby mode the device can remain potentially ready for use for several days, the active operating format consumes energy in 8-10 hours. This applies to models with 700-800 mAh batteries. We are talking about average indicators, since the rate of reduction in battery capacity will also be affected by weather conditions. For example, a winter echo sounder for a smartphone consumes 15-20% more energy, which should be taken into account. Some manufacturers also provide several batteries in one set. Moreover, depending on the format of the battery, it may be possible to recharge it from a car cigarette lighter. In this case, you can ensure an almost non-stop scanning process by charging and changing batteries.

Main characteristics of the sensor

The efficiency of a device is primarily determined by its power. For portable sonars it rarely exceeds 300 W. Models with this potential are optimally suited for regular fishing from the shore with a casting range of about 30-40 m. Power affects the detection depth, which can reach from several tens to hundreds of meters - most models operate in the range of 40-500 m. The frequency will also affect the emission range. The lower it is, the higher the range of action. For example, 50 kHz will provide the same 500 m. But it is important to consider that the function of the wireless echo sounder sensor for a smartphone will also be affected by the characteristics of the water. Thus, in conditions of increased mineralization, the monitoring depth can be halved. However, you should not focus solely on power versus frequency. The scanning angle is also important, which on average varies from 15° to 45°. This is the amount of coverage of the underwater space - accordingly, from a narrow field to a wide one.

Model Deeper Smart Sonar

One of the best models of portable echolocators in the segment from the famous Estonian manufacturer Deeper. Features of the device include the presence of two radiation points - transducers with frequencies of 90 and 290 kHz cover angles of 55° to 15°. This means that the smartphone fish finder sensor will reflect the fish on the screen in high detail. The functionality of the model also deserves attention. The device has a GPS module, so scanning data can be superimposed on a real cartographic diagram in a special application. This feature allows you to record information about visited objects.

The high power of the sensor had a negative impact on autonomy. If you need a winter echo sounder for your smartphone, you will have to count on no more than 5 hours of operation on a single charge. Moreover, the battery volume is replenished for at least 2 hours. The disadvantages of this proposal include the high cost, which is about 20 thousand rubles.

Model Deeper Smart Fishfinder

A modification from the same manufacturer, but with more modest capabilities. The signal propagation reaches 40 m, and high scanning accuracy is maintained at depths of about 50 m. Moreover, the device also has two beams, but with smaller ranges. This version also inherited a lack of autonomy - the battery can function for 4 hours. As for the strengths, they are reflected in high-quality monitoring with a high degree of detail and the presence of a lunar calendar. On average, the price of an echo sounder for an Android smartphone of this modification is 10-11 thousand. That is, this is a budget version of the previous device with understandable limitations in technical and operational qualities.

FishHunter Directional 3D model

A high-tech model of a portable echo sounder that has five transducers. The frequency range extends from 381 to 675 kHz, which makes it possible to accurately reflect the position of the fish. However, the depth of exploration still limits this echo sounder for a smartphone on Android to 55 m. But the device also has a GPS module, with which you can create an underwater map of the object.

Additional functionality of the model includes tips for anglers. So, during the scanning process, the device signals which place is best to throw the hook. As for the 3D prefix, it indicates the possibility of three-dimensional modeling of the map with the highlighting of the relief texture. Previously, only stationary, expensive models were provided with such an option, but the price of an echo sounder for an Android smartphone from FishHunter is quite acceptable for its class - an average of 21 thousand.

How to choose the right model?

Mainly, the main operational qualities should be taken into account - radiation frequency, scanning depth and battery capacity.
You can then move on to additional functions. If the possibility of 3D mapping is more of an ergonomic option, then, for example, a GPS receiver can be classified as a useful practical tool. With its help, the fisherman will be able to draw up complete maps, indicating the places visited and the corresponding comments on them. In terms of quality selection, it is better to focus on large manufacturers. It is not advisable to purchase an echo sounder for a smartphone from China at prices of 5-7 thousand, since even with wide functionality they are unlikely to provide high accuracy of bottom research. Only in rare cases do such products confirm the high originally stated parameters in practice. The availability of external protection should also be taken into account - the sensitive element must have at least a waterproof shell and a coating that protects against mechanical influences.

Nuances of operating echo sounders for smartphones on Android

At the first stage of application, synchronization should be established between the mobile device and the sensor. Special applications from the sonar manufacturers themselves help to automatically perform this procedure. Next, you should secure the smartphone at the place of use. Since it will interfere with the fishing process, it would be a good idea to provide a special holder and secure the body to it. Some sensor kits include similar devices. After this, the echo sounder itself for a smartphone on Android must be securely fixed to a fishing line or a separately cast rope. But it is important not to confuse its direction - the beam on the working surface of the sensor should be oriented downward.

Conclusion

Using portable bottom monitoring equipment is certainly a convenient way for anglers to obtain the information they need. But their performance qualities are significantly inferior to their stationary counterparts with their own displays. This difference is especially visible in the examples of echo sounders for smartphones from China with price tags no higher than 8-10 thousand. As a rule, these are low-power models with low efficiency. But in this case, what justifies the use of such sensors other than ergonomics? Still, such gadgets can become useful if you plan to use them at shallow depths when casting from the shore. But for going out into open waters on a boat, for example, such equipment simply won’t make sense.

fb.ru

Getting to know the echo sounder, or the specifics of sonar

With the advent of inexpensive echo sounders, navigating the water has become much easier. Previously, the main tool of the “small size” was the pilot, which often had not seen the corrector’s hand for years, and therefore did not take into account changes in the structure of the bottom. Today, a picture of the bottom in real time will no longer surprise anyone.

For fishermen and diving enthusiasts, there are expensive structural scanners that show a color picture of the bottom with amazing accuracy.
Travelers have access to chart plotters that combine the functions of a navigator, echo sounder, and engine control panel.
Owners of slow-moving yachts are helped by forward-looking echo sounders. For high-speed vessels in shallow depths, these devices are not relevant, since they differ little in functionality from a conventional sonar. After all, the sensor is capable of “looking” ahead at only 2-3 depths.
The most popular segment is inexpensive single- and double-beam echo sounders. They are used by fishermen, tourists, and even ice fishing enthusiasts.

Even the simplest device is capable of measuring the temperature of sea water, reporting a drop in voltage on the on-board network, and also informing with an audible signal about a sharp decrease in depth. We will not consider the “fish” indication, because today we are talking about the benefits of sonar for navigation in conditions of insufficient depth.

Focusing on sound

The principle of operation of an echo sounder has not changed over the last hundred years. The size of the devices has been reduced and signal processing algorithms have been optimized. But the transceiver still sends a high-frequency signal deep into the water and waits for it to return, reflected from the bottom topography.

Depending on the density of the soil, the reflected signal weakens. To obtain depth data, the device analyzes the signal return time. The structure of the bottom is characterized by signal weakening. Thus, on the echo sounder screen we see the bottom topography of various shades - from black (rock) to light gray (silt).

Indication of “fish” is based on identifying air inclusions in the water column - swim bladders of the supposed fish. While this option may be of some interest to fishermen, for navigation it is absolutely useless and distracts attention.

In the process of controlling a high-speed motor boat on the navigable rivers of central Russia, the absolute values of the depth are not so important as the dynamics of its change. If there are 5-6 meters under the keel, and the picture of the bottom suddenly creeps up, this is a reason to correct the course - most likely, we have lost our way and are heading towards a landfall. In Karelia, it is quite possible to break a motor gearbox even at a depth of more than 5 meters. Pitfalls often stand alone and do not come to the surface. Coupled with fluctuations in water level in such reservoirs with a rocky bottom, you need to be especially careful.

It’s a different matter when the depth is 30, 50, or even more than 100 meters. In this case, the echo sounder readings do not have priority. However, do not underestimate the importance of this device - after all, sooner or later you will have to walk in the coastal strip, where there may be submerged piles, hulls of large ships and rock spits.

In order to avoid chaotic changes in readings at the speed of a planing vessel, it is enough to manually limit the depth range. Almost all devices allow you to do this. Thus, harmonics that are multiples of the actual depth are eliminated.

Installing an echo sounder with your own hands

It's a pleasure to spend time improving your boat. Installing a fish finder is a rewarding activity. Therefore, arm yourself with knowledge and begin installation.

There are not many options regarding the display. We install it on top of the horizontal part of the panel or on the inclined one facing the boatmaster. It is important that the screen does not block the view when moving under the awning and does not glare in sunny weather.

The situation with a remote sensor is much more complicated. Since it houses not only the receiver and transmitter, but also a temperature sensor, it is important to ensure reliable contact with water. By design, sensors differ in external (outboard) and built into the bottom. Each of these options has its own disadvantages.

Since we still belong to the endangered subspecies “Homo sovieticus”, since childhood we have had a desire for experiments, creativity and various studies. So we will place the echo sounder sensor from the inside on the bottom next to the transom.

We will consider possible options in the next chapter.

Glue the echo sounder sensor into the body

Indeed, it is very tempting to be able to use an echo sounder at any speed, without interfering with the bottom structure, without fear of damaging the sensor, and without having a fountain of splashes behind the transom. Why doesn't everyone do this? Let's consider cases when this method is impossible or requires too much R&D ☺

Body with transverse steps. The aerated bottom has a beneficial effect on the speed performance of the vessel, but is completely unsuitable for installation inside an echo sounder sensor due to air bubbles in the boundary environment. In this case, the echo sounder will only work while stationary and when moving in displacement.
Wooden body. Not plywood covered with fiberglass, but real wood. Due to the porous structure of the board, the device screen is treacherously silent.
Displacement hulls with a whaleboat stern, which ends up in the air in the waves. At this moment, the instrument readings are lost.
Some plastic enclosures are double-walled. In such “sandwiches” the space between the fiberglass is filled with two-component polyurethane foam, and to install the sensor you need to cut the inner “shell”, which is a shame, especially on a new boat.
The space in the area of the keel and longitudinal steps on the keel hulls. Swirls and air bubbles will not allow the device to work smoothly, so before final installation, we will check the functioning of the device in several places and select the best one.

To ensure a constant environment, antifreeze, epoxy resin, auto plasticine, silicone sealant, hot melt adhesive, and lubricant for a medical device (ultrasound) are used. It is clear that all these materials introduce errors into the instrument’s readings and impair sensitivity, but practice has shown that such a scheme works.

Bonded sensors work great on fiberglass and aluminum boats. However, no one can guarantee the functionality of the proposed circuits on your case. Therefore, it remains to proceed by trial and error.

Looking for an echo

So, the cable is stretched according to all the rules, the monitor is secured and carefully covered with a lid, and in the stern next to the bilge pump there is an echo sounder sensor. Our task is to find the optimal location so that the sensor does not interfere with communications (for example, draining subsoil water), and the readings are not too affected by air bubbles that get under the bottom while moving. There are three ways to achieve the desired result.

Method one

Screw the sensor to the transom from the inside, directing the beam down perpendicular to the surface of the water. In this case, a constant presence of a certain level of subsoil water is necessary so that there is no air wedge between the sensor and the bottom. The author of this article for a long time had a boat in which for the echo sounder to work correctly it was enough to pour only 2 liters of sea water under the sled.

Moreover, this was found experimentally when 5 or 6 sensor positions were tested. The echo sounder did not want to work. It was decided to stop the races and raise the boat. As usual, after being placed on the trailer, the drain scupper was opened to dry, but there was no water under the sleds. Deciding to straighten the boat on the trailer, he drove it back into the water without tightening the plug. Imagine the surprise when the echo sounder suddenly started working properly. Reception even at speeds over 60 km/h. As a result, each trip began with pouring a two-liter bottle on the floor, which surprised the guests.

Second way

It consists of gluing the sensor to silicone on a flat area of the bottom between the steps. We try to fix the sensor plane not parallel to the bottom, but parallel to the water. However, a slight deviation (up to 10-15 degrees) is acceptable.

We use silicone sealant or autoplasticine as a fixing mass. If the tests show that the chosen location is correct, you can re-glue the sensor with epoxy glue. However, you should make sure that there are no air bubbles between the sensor and the bottom.

Third way

To some extent, it combines the advantages of the first and second methods. Its purpose is to have a conductive liquid between the sensor and the bottom, but there is no liquid in the boat itself. A bit tricky, right? Let's try to figure it out and install the sensor.

For installation, we need a container with a narrow neck and a flat base. To do this, cut off the top part of a two-liter plastic bottle or polyethylene canister. We will fix the sensor under the dome closer to the bottom. The sensor wire will come out through the neck of the bottle.

The main task is to securely fix the edge of the container to the bottom. The connection must be tight and reliable. You can use silicone sealant or epoxy resin. For better joint strength, the edge of the plastic adjacent to the bottom is roughened using sandpaper. Leave the glued dome to dry. After polymerization, we proceed to the most important thing.

Fill the container through the neck with antifreeze. This will allow you to leave the boat with the sensor in the cold for the winter and forget that the echo sounder is installed in an abnormal way. If you can securely fix the dome to the bottom, and the sensor to the dome, you will get the best option for installing the sensor. It is worth noting that if you choose the third method, you should not lay the sensor cable in advance. The first step will be threading the connector into the neck of the bottle, then gluing, filling, testing, and only at the final stage - laying the cable.

It is worth noting that installation from inside the housing affects the accuracy of seawater temperature measurement, damping the readings. Therefore, if temperature is a priority indicator for you, either take the sensor overboard, or wait 5-10 minutes for changes in water temperature to reach the sensor, heating (or cooling) the bottom. In aluminum alloy cases this effect is minimal, in fiberglass cases it is more pronounced.

A correctly installed echo sounder sensor does not reveal its presence in any way and pleases the navigator with stable readings on the device display.

Let's sum it up

An echo sounder is not only a device that shows depth. This is an indispensable tool when operating a small boat. Based on its readings and checking them with the pilot, you can confidently navigate in difficult places, greatly reducing the risk of running aground or damaging the propulsion.

Expensive models of chart plotters occupy a central position on the panel, displacing other devices. Essentially, the chartplotter screen is the central console of the on-board system. It is capable of replacing all other telemetry - positioning on the map, navigation system, speedometer, compass, engine monitoring devices and clock. And only the principle of redundancy forces us to have a separate analog compass and a spare navigator.

proboating.ru

An amateur fisherman's echo sounder.

(Voitsekhovich V., Fedorova V.. Radio. 1988, No. 10, p. 32...36)

Not only fisherman, of course. An electronic fish finder can be useful in a wide variety of underwater applications.

The echo sounder can be manufactured in two versions: with depth measurement limits of up to 9.9 m (its display contains two luminescent indicators) and 59.9 m (three indicators). Their other characteristics are the same: instrumental error - no more than ±0.1 m, operating frequency - 170...240 kHz (depending on the resonant frequency of the emitter), pulse power - 2.5 W. The ultrasonic emitter, also known as the echo signal receiver, is a barium titanate plate with a diameter of 40 and a thickness of 10 mm. The power source for echo sounders is a Corundum battery. Current consumption is no more than 19 and 25 mA (in echo sounders for shallow and deep depths, respectively). Dimensions of echo sounders - 175x75x45 mm, weight - 0.4 kg.

A block diagram explaining the operation of the echo sounder is shown in Fig. 131. Clock generator G1 controls the interaction of the device components and ensures its operation in automatic mode. The short (0.1 s) rectangular pulses generated by it are repeated every 10 s. With their front, these pulses set the digital counter PC1 to the zero state and close the receiver A2, making it insensitive to signals while the transmitter is operating.

Rice. 131. Block diagram of an echo sounder

The schematic diagram of an echo sounder with a depth measurement limit of 59.9 m is shown in Fig. 132. Its transmitter, self-excited at the frequency of the ultrasonic emitter BQ1, is made using transistors VT8, VT9. Turning the transmitter on and off is controlled by a modulator - a standby monostable (VT11, VT12, etc.), which supplies power to the transmitter through its switch (VT10) for 40 μs.

Rice. 132. Schematic diagram of an echo sounder

*) Its calculation is simple: at a speed of sound propagation in water of 1500 m/s, in 1/7500 s the front of the signal traveling a double path will move 0.2 m; and, accordingly, the lowest unit on the meter display will correspond to a depth of 0.1 m.

apox.ru

Radio circuits for everyday use

An electronic echo sounder can be useful for a wide variety of underwater activities - not just fishing.
The echo sounder can be manufactured in two versions: with depth measurement limits of up to 9.9 m (its display contains two luminescent indicators) and 59.9 m (three indicators).
Their other characteristics are the same:
instrumental error - no more than ±0.1 m,
operating frequency - 170...240 kHz (depending on the resonant frequency of the emitter),
pulse power - 2.5 W.
The ultrasonic emitter, also known as the echo signal receiver, is a barium titanate plate with a diameter of 40 and a thickness of 10 mm.
The power source for echo sounders is a Corundum battery.
Current consumption is no more than 19 and 25 mA (in echo sounders for shallow and deep depths, respectively).
Dimensions of echo sounders - 175x75x45 mm, weight - 0.4 kg.

Schematic diagram of an echolocator

At the end of the transmitter operation, the A2 receiver opens and acquires normal sensitivity. The echo signal reflected from the bottom is received by the same BQ1 and closes the key S1. The measurement is completed, the measured depth is displayed on the indicators of the PC1 counter.
Depth calculation is simple: at a speed of sound propagation in water of 1500 m/s, in 1/7500 s the front of the signal traveling a double path will move by 0.2 m; and, accordingly, the lowest unit on the meter display will correspond to a depth of 0.1 m.

The next clock pulse will again transfer the counter PC1 to the zero state and the process will repeat.

The schematic diagram of an echo sounder with a depth measurement limit of 59.9 m is shown in Fig. 2.

The clock generator is assembled on transistors VT13, VT14. The pulse repetition rate depends on the time constant R28-C15.

The filaments of the luminescent indicators HG1-HG3 are powered by a voltage converter made of transistors VT17, VT18 and transformer T2.

Transformer T2 is made on a ferrite (3000NM) ring of standard size K16x 10x4.5. Winding I contains 2x180 turns of PEV-2 0.12 wire, winding II - 16 turns of PEV-2 0.39 wire.

Thin leads are soldered to the silvered planes of the emitter plate using Wood's alloy. The emitter is assembled in an aluminum cup with a diameter of 45...50 mm (the bottom part of the oxide capacitor housing). Its height - 23...25 mm - is specified during assembly. A hole is drilled in the center of the bottom of the glass for a fitting, through which a coaxial cable 1...1.25 m long will be routed, connecting the ultrasonic head with the electronic part of the echo sounder. The emitter plate is glued with 88-N glue to a disc made of soft microporous rubber 10 mm thick. During installation, the cable braid is soldered to the fitting, the central conductor is soldered to the terminal of the lining glued to the rubber disk, the terminal of the other emitter plating is to the cable braid. The emitter assembled in this way is pushed into the glass. The surface of the emitter plate should be 2 mm below the edge of the glass. The glass is fixed strictly vertically and filled to the edge with epoxy resin. After it is installed, the end of the emitter is sanded with fine-grained sandpaper until a smooth flat surface is obtained. The mating part of connector X1 is soldered to the free end of the coaxial cable.

Setting up an echo sounder

The operation of the transmitter is checked with an oscilloscope operating in standby sweep mode. It is connected to winding II of transformer T1. With the arrival of each clock pulse, a radio frequency pulse should appear on the oscilloscope screen. By adjusting transformer T1 (roughly, by selecting the capacitance of capacitor C 10), its maximum amplitude is achieved. The amplitude of the radio pulse on the piezo emitter must be at least 70 V.

The receiver and modulator are adjusted using echo signals. To do this, the emitter is attached with a rubber band to the end wall of a plastic box measuring 300x100x100 mm (to eliminate the air gap, this place is lubricated with technical petroleum jelly). Then the box is filled with water, the VD3 diode is removed from the receiver and an oscilloscope is connected to the receiver output. The criterion for the correct configuration of the receiver, modulator and the quality of the ultrasonic emitter is the number of echo signals observed on the screen, resulting from multiple reflections of the ultrasonic pulse from the end walls (spaced 300 mm apart) of the box. To increase the visible number of pulses, select resistors R2 and R7 in the receiver, capacitor C 13 in the modulator, and adjust transformer T1.

To measure the depth of a reservoir, the lower part of the ultrasonic head is immersed in water by 10...20 mm. It is better to have a special float for it.

(Voitsekhovich V., Fedorova V.. Radio. 1988, No. 10, p. 32...36)

radio-uchebnik.ru

What is a smartphone echo sounder?

Operating principle of the device

Power supply system

The lack of wires causes one of the main disadvantages of such sonars. The fact is that fishing is a long process, and the autonomy of wireless electronics is always limited to a few hours. The sensors are equipped with batteries with an average capacity of 500-1000 mAh. Although in standby mode the device can remain potentially ready for use for several days, the active operating format consumes energy in 8-10 hours. This applies to models with 700-800 mAh batteries. We are talking about average indicators, since the rate of reduction in battery capacity will also be affected by weather conditions. For example, a smartphone consumes 15-20% more energy, which should be taken into account. Some manufacturers also provide several batteries in one set. Moreover, depending on the format of the battery, it may be possible to recharge it from a car cigarette lighter. In this case, you can ensure an almost non-stop scanning process by charging and changing batteries.

Main characteristics of the sensor

Model Deeper Smart Sonar

Model Deeper Smart Fishfinder

FishHunter Directional 3D model

How to choose the right model?

Mainly, the main operational qualities should be taken into account - radiation frequency, scanning depth and battery capacity. Then you can move on to additional functions. If the possibility of 3D mapping is more of an ergonomic option, then, for example, a GPS receiver can be classified as a useful practical tool. With its help, the fisherman will be able to draw up complete maps, indicating the places visited and the corresponding comments on them. In terms of quality selection, it is better to focus on large manufacturers. It is not advisable to purchase an echo sounder for a smartphone from China at prices of 5-7 thousand, since even with wide functionality they are unlikely to provide high accuracy of bottom research. Only in rare cases do such products confirm the high originally stated parameters in practice. The availability of external protection should also be taken into account - the sensitive element must have at least a waterproof shell and a coating that protects against mechanical influences.