Hmm, yoda_daro claims that this is a test to determine their sexuality...
Instruction The frames of the film merge for us into continuous movement due to ...
An ultrasonic transducer is a generator of powerful ultrasonic waves. As we know, a person does not hear the ultrasonic frequency, but the body feels it. In other words, the ultrasonic frequency is perceived by the human ear, but a certain part of the brain responsible for hearing cannot decipher the data. sound waves. Those who build audio systems should be aware that high frequency is very unpleasant for our hearing, but if we raise the frequency to an even higher level (ultrasound range), then the sound will disappear, but in fact it is. The brain will try unsuccessfully to decode the sound, resulting in headache, nausea, vomiting, dizziness, etc.
Ultrasonic frequency has long been used in the most different areas science and technology. Using ultrasound, you can weld metal, wash and much more. Ultrasound is actively used to repel rodents in agricultural machinery, since the body of many animals is adapted to communicate with their own kind in the ultrasonic range. There is also data about repelling insects using ultrasound generators, many companies produce such electronic repellents. And we suggest that you independently assemble such a device, according to the above scheme:
Consider the design of a fairly simple high-power ultrasonic gun. The D4049 chip works as an ultrasonic frequency signal generator, it has 6 logic inverters.
The microcircuit can be replaced with a domestic analogue K561LN2. A 22k regulator is needed to adjust the frequency, it can be reduced to an audible range if the 100k resistor is replaced with 22k, and the 1.5nF capacitor is replaced with 2.2-3.3nF. The signals from the microcircuit are fed to the output stage, which is built on only 4 medium-power bipolar transistors. The choice of transistors is not critical, the main thing is to choose complementary pairs that are as close as possible in terms of parameters.
As a radiator, you can use literally any RF heads with a power of 5 watts or more. From the domestic interior, you can use heads like 5GDV-6, 10GDV-4, 10GDV-6. Such high-frequency heads can be found in acoustic systems manufactured in the USSR.
It remains only to arrange everything in the body. To direct the ultrasonic signal, you need to use a metal reflector.
ultrasonic generator is a device that converts mechanical or electromagnetic energy into the energy of acoustic vibrations of ultrasonic frequency. Modern ultrasonic generators operate from a household or industrial power supply, which means they are electrical appliances.
Usually, circuit diagram ultrasonic generator is based on semiconductor elements in the form of digital microcircuits and transistors.
The main elements of the circuit of any ultrasonic generator are the master pulse generator, which determines the frequency of the generated ultrasound, and power transistors, which amplify the pulses of the master generator to the required power, thereby determining the power of the ultrasound.Power transistors operate in a switching mode in which the transistors are either saturated or off. At the same time, the minimum power is dissipated in the collector circuit of each transistor, which increases the efficiency of the ultrasonic generator up to 90%.However, transistor circuits also have disadvantages. First, the speed of the transistor has a finite value, which is especially evident at high ultrasonic frequencies. The transistors do not have time to switch, and a through current occurs, which reduces the output power of the generator. Secondly, in the switching mode, the generator output produces rectangular pulses with higher harmonics of the fundamental frequency, which degrade the operation of transistors and ultrasonic transducers.
Depending on the required generator power, the output stage on power transistors can be made according to a push-pull circuit (generator power up to 100 W), half-bridge circuit (generator power up to 300 W) or bridge circuit (generator power > 300 W).
The figure below shows simplified diagrams of the output stages of ultrasonic generators.
Push-Pull Power Amplifier
In a push-pull circuit, the supply voltage is selected from the condition E< U k /2, где Е- напряжение питания, U k -максимально допустимое напряжение на коллекторе (или стоке) транзистора.
Half-bridge power amplifier
In a half-bridge circuit, the power supply is connected to a bridge, in which transistors are connected between points vg, and the output transformer is connected between points ab. The excitation pulses are fed to the transistors T1 and T2 from the transformer Tr1 in antiphase. On a closed transistor, the entire supply voltage E drops, so it is necessary that E< U k .
Bridge Power Amplifier
In the bridge circuit, the output stage of the ultrasonic generator is made up of four transistors. The power supply is connected to the diagonal ab, and the output transformer is connected to the diagonal vg. The arms of the bridge are made up of transistors T1-T4. The base voltage U b-e is applied to them so that when transistors T1 and T3 are open, then transistors T2 and T4 are closed, and vice versa. Such switching of transistors leads to the fact that the power dissipated in the load is four times the power supplied by a single transistor, and twice the power supplied by a push-pull or half-bridge circuit. The supply voltage is selected from the condition E< U k .
To obtain higher powers, a power addition scheme can be used. The figure below shows one of the options for such a circuit of an ultrasonic generator with the addition of the power of half-bridge cells.
Here, n cells are connected in series in the power supply circuit. Each of them is a cascade of power transistors, made according to a half-bridge circuit. The cells are excited from a common master oscillator G, and even and odd transistors are excited in antiphase. The outputs of all cells are connected to a common output transformer Tr2, where the power is added. The supply voltage E is selected from the condition E< n*U k .
The output stage of the ultrasonic generator, in addition to power transistors, also contains auxiliary elements that match the ultrasonic generator with an ultrasonic transducer, and also serve to indicate and adjust the generated ultrasound.
The master oscillator can be implemented according to different schemes, but three are commonly used:
A circuit based on an independent pulse generator that allows you to easily change the frequency of ultrasound over a wide range, but there will be no frequency stability.
A feedback oscillator circuit that allows generating ultrasound at the resonant frequency of an ultrasonic transducer in the self-oscillation mode. However, the stability of the frequency is determined by the consistency between the generator, the converter and the working tool.
A circuit based on a self-tuning oscillator that allows you to stabilize the frequency of ultrasound with any changes in the acoustic power of ultrasonic vibrations on a working tool.
The scheme of the master pulse generator is selected depending on the specific application of the ultrasonic generator. Simple portable ultrasonic instruments use a simple independent pulse generator circuit. If we are talking about industrial installations of ultrasonic processing of materials, where the stability of the ultrasound frequency is required, a circuit with auto-tuning of the frequency of the master oscillator is used.
The figure below shows a circuit variant of an ultrasonic generator with automatic frequency control.
The load of the generator is a magnetostrictive transducer M. The generator consists of two stages. The first is the exciter in the form of a master oscillator on transistors T1 and T2, powered by a rectifier with an output voltage of E1. The second is the output stage in a half-bridge circuit on transistors T3 and T4. The load M is connected to the generator output through a matching transformer Tr2, a matching circuit C1, L1 and C2, L2, a differential feedback transformer Tr3. The feedback voltage from the transformer Tr3 is fed into the base circuits of the transistors T1 and T2 and synchronizes the operation of the master oscillator.
The figure below shows a diagram of an ultrasonic generator based on thyristors TB2-160. This is a diagram of an industrial ultrasonic installation powered by a three-phase power supply.
Here, CU is a thyristor control unit, and BACH is an auto-tuning unit.
The figure below shows a variant of an ultrasonic generator based on a GU-39B vacuum tube. The load is a magnetostrictive transducer M, connected to the anode circuit of the lamp through a transformer Tr1. Resistor R2 is used to adjust the power of the generator.
Scheme of an ultrasonic generator on an electron tube
Below is a diagram of an ultrasonic generator based on GU-56 type electron tube triodes, made according to a push-pull circuit with self-excitation.
Scheme of an ultrasonic generator on two electron tubes.
Manufacturers of ultrasonic devices and installations do not provide a schematic diagram of the entire ultrasound generator in the description of their products. Therefore, it is not possible to give a diagram of a commercial ultrasound generator here on the site.
However, in radio engineering magazines such as, RADIO, and, RADIO HAMMER, one can find diagrams of simple ultrasonic generators, and descriptions are given below for self-manufacturing some ultrasonic devices.
An article from the magazine, RADIO, No. 7, 1990 provides a diagram of a switching power supply for a home-made computer, which can be used as an ultrasound generator if an ultrasonic emitter is connected to the secondary winding of the output transformer.
A slightly modified circuit is shown in Fig. 1
Figure 2 shows signal diagrams at characteristic points of the circuit.
The primary winding (I) of the main transformer Tr2 of the converter is included in the diagonal of the bridge formed by transistors VT1, VT2 and capacitors C9, C10. The base circuits of these transistors are powered by the windings II and III of the T1 transformer, the primary winding of which receives a step voltage from the shaper assembled on the DD1, DD2 microcircuits.
The master oscillator of the shaper is assembled on inverters DD1.1 and DD1.2 and generates oscillations with a frequency determined by the variable resistor R4.1, resistor R4.2 and capacitor C6. By changing the capacitance of the capacitor C6, it is possible to change the frequency of the generated ultrasound over a wide range, and by changing the resistance of the resistor R4.1, adjust the generator to the resonant frequencies of the ultrasonic emitter.
Pulses from the outputs of triggers DD2.1 and DD2.2 are fed to the inputs of the elements DD1.3 and DD1.4, as a result of which pulse sequences with a duty cycle of 4 are formed at their output. Their difference (Fig. 2, diagram, T1, exchange I ,) has the form of pulses of alternating polarity with the same duration and duration of pauses between them.
Through the transformer T1, this step voltage is transmitted to the base of the transistors VT1, VT2 and opens them in turn. The presence of pauses between pulses guarantees the complete closure of each of them before opening the other.
The shaper chips DD1, DD2 are powered by a voltage of 12 V from a transformerless source, consisting of a ballast capacitor C3, a rectifier bridge VD2, a zener diode VD3 and filter capacitors C7, C8.
The choice of such a supply voltage for microcircuits made it possible to use the T1 transformer with the highest possible transformation ratio (10: 1), which reduced the current load on the elements DD1.3, DD1.4 and made it possible to do without additional transistor switches in their output circuit.
The device is assembled on a printed circuit board (Fig. 3) from double-sided foil fiberglass with a thickness of 1.5 mm.
Transistors VT1, VT2 are mounted on a 40x22 mm plate made of double-sided foil fiberglass 1.5 mm thick, soldered perpendicular to the board. KT704A transistors can be replaced with KT872A transistors.
Transformer T1 is wound on an annular magnetic circuit of size K10x6x5 made of 3000NM ferrite.
Its winding I contains 180 turns of PELSHO 0.1 wire, windings II and III - 18 turns of PELSHO 0.27 each.
The magnetic circuit of the transformer T2 -K28x16x9 from ferrite 2000 NM. Winding I consists of 105 turns of PELSHO 0.27 wire, winding II of 14 turns of PEV-2 wire with a diameter of 1 mm.
The turns of the windings of each transformer must be evenly distributed throughout the entire magnetic circuit.
ULTRASOUND AGAINST RODENTS
(from the magazine, RADIO, No. 8 1996)
The proposed device (Fig. 1) is an ultrasonic generator, the oscillation frequency of which is modulated by infrasonic oscillations with a frequency of 6...9 Hz.
The infrasonic frequency generator is formed by elements DD1.1, DD1.2, resistors R1, R2 and capacitor C1. A chain of resistors R3, R4, R6, capacitor C2, diodes VD1, VD2 and transistor VT1 is designed to periodically, withdraw, the frequency of an ultrasonic oscillator-symmetric multivibrator assembled on elements DD1.3, DD1.4, resistors R5, R7 and capacitors C5 , C6. Its frequency periodically, with a frequency of 6 ... 9 Hz, changes from 25 to 50 kHz.
Transistors VT2-VT5, each of which is connected by an emitter follower, form a push-pull bridge amplifier, the load of which is the dynamic head VA1 - it emits frequency-modulated ultrasound. Diode VD3 and capacitors C3, C4 is a filter in the power circuit of the DD1 microcircuit. Diode VD3, in addition, protects the microcircuit from failure in the event of an erroneous polarity of switching on the power supply of the entire device.
What is the working principle of the ultrasonic siren? If, for example, the emitter junction of the transistor VT1 is closed with a wire jumper, it will be permanently closed, so the diodes VD1 and VD2 will also be closed and the ultrasonic generator will operate at a constant frequency of about 25 kHz. Since the values of resistors R5, R7 and capacitors C5, C6 included in the multivibrator are equal to each other, this generator generates strictly symmetrical rectangular pulses that provide the BA1 head with work without distortion, This is the lowest frequency of the device.
If now the upper (according to the scheme) output of the resistor R3 is switched to the positive conductor of the power source, and the jumper is removed from the emitter junction of the transistor VT1, then the transistor will be constantly in the open state. In this case, the diodes VD1 and VD2 will alternately open at a frequency of 50 kHz - twice the frequency of the ultrasonic generator, which is the highest frequency of the device.
In general, the device works as follows. When the low-level signal at the output of element D1.2 jumps to a high one, within about 30 ms the frequency of the ultrasonic generator changes (due to the smooth opening of the transistor VT1) from 25 to 50 kHz, after which it remains equal to 50 kHz for 35 ms. Then when the signal high level at the same output of the DD1.2 element, it is again replaced by a low one, the generator reduces its frequency within 30 ms (due to the smooth closing of the transistor VT1) from 50 to 25 kHz, after which it forms a low frequency pulse sequence for 35 ms. Further, the operation of the device is repeated cyclically.
The frequency of the infrasonic generator can be changed by selecting resistor R2, the rise and fall time of the frequency of the ultrasonic generator by selecting resistor R3, and the value of the highest frequency of the device by resistor R6. If it is necessary to change the lower frequency (usually in the direction of decreasing it up to 20 kHz), the resistance of the resistors R5 and R7 is simultaneously selected, while maintaining the equality of their ratings.
The power of ultrasonic vibrations will increase if a 6GDV-4 head is used as an ultrasonic emitter or two 3GDV-1 heads are connected in parallel.
It is recommended to power the device from a stabilized voltage source of appropriate power. So, with a supply voltage of 9 V and an eight-ohm load, the current consumed by the device does not exceed 0.5 A, and with a four-ohm load - 1 A.
To make it more difficult for rodents to adapt to a scaring signal, it is advisable to use a more complex infrasonic frequency generator, for example, a pseudo-random pulse train generator.
A diagram of the practical design of such a generator is shown in Fig. 2.
Fig.2
It contains two additional infrasonic generators on the elements DD2.1, DD2.2 and DD2.3, DD2.4, which are individually capable of generating rectangular pulses with a frequency of about 1.9 and 3.6 Hz, respectively. The frequencies of all three generators are chosen so that they are not a multiple of one another. Then, instead of methodical frequency modulation of ultrasound, it is possible to obtain whole trills, reminiscent (of course, in the audio range) not only bird singing, but also mouse and rat squeaks in stressful situation. A person can hear it if you approximately double the capacitance of the capacitors C5 and C6 of the generator on the elements DD1.3, DD1.4 and thereby reduce its frequency to the audio range. It is in this mode that a selection of resistors R9, R11 and R2 change the frequency of all three infrasonic generators.
A device with such an infrasonic frequency oscillation generator most accurately imitates the alarming squeak of rodents, which is not perceived by the human ear, but is perfectly distinguishable by rodents.
REPAIR OF THE RETONA ULTRASONIC WASHING MACHINE
(from the magazine, RADIO, No. 6 2006)
The schematic diagram, restored from the configuration of the printed conductors on the board, is shown in the figure.
The generator of ultrasonic vibrations is the simplest high-frequency generator based on a VT1 transistor, made according to the classical inductive, three-point scheme, with a BQ1 piezoelectric radiator as a frequency-setting element. The HL1 LED serves as an indicator of the operation of the generator - the presence of a high-frequency voltage at the emitter of the transistor. Diode VD1 protects the LED from reverse polarity voltage. Transformer T1 and a bridge of diodes VD2-VD5 feed the generator with a voltage pulsating at a frequency of 100 Hz.
DEVICE AND REPAIR OF ULTRASONIC WASHING MACHINE "ULTRATON MS-2000"
(from the magazine, RADIO, No. 1 2007)
The schematic diagram of the device is shown in fig. one.
Fig.1
The main element of the device is a pulse generator with a half-bridge output on the IR53HD420 chip.
Its internal components are shown in Fig.2. This hybrid IC is designed for use in low-power push-pull switching converters and is a well-known IR2153 IC for electronic ballasts, supplemented with output FETs and a diode with a fast reverse resistance recovery time.
The parameters of this chip are as follows:
The maximum supply voltage of the transistor half-bridge is 500 V
The resistance of the drain-source channels of field-effect transistors in the open state is 3 ohms
The maximum average drain current of these transistors at a case temperature of 85 ° C is 0.5 A
Maximum switching frequency - 1 MHz
Maximum power dissipation - 2 W
Diode reverse resistance recovery time - 50 nsec.
The mains voltage through the current-limiting resistors R1, R2 and the filter L1, C1, C2 is supplied to the diode bridge VD1. The rectified voltage pulsating at a frequency of 100 Hz, having passed through the FU1 fuse-link, is used to power the device. After 1...2 sec. after turning on the device in the network, the voltage across the capacitor C3 reaches 9 V and the DD1 chip starts working. Its supply voltage in steady state (12 ... 13 V) is limited by an internal zener diode. With the values \u200b\u200bof the circuit elements C4, R3, R4 indicated on the diagram, the frequency of the output pulses of the microcircuit is about 20.5 kHz ( exact value set with a trimming resistor R4).
When the switching transistors are turned on in turn, the potential of the connection point of the source, upper, transistor VT1 and drain, lower, transistor VT2 becomes approximately equal to either +310 V applied to the drain of transistor VT1, or zero. In this case, the voltage between the gate and the source of the transistor VT1 should vary from 0 to +12 V.
The primary winding of the transformer T1 is connected to the output of the IR53HD420 microcircuit through an isolation capacitor C6. Its secondary winding is loaded with a BQ1 piezoceramic ultrasonic transducer.
LED HL1, turning on after 1 ... 2 seconds. after applying mains voltage to the device, it signals the normal operation of the DD1 chip. Of course, it will also glow if there are breaks in the windings of the transformer T1 or if the emitter BQ1 is faulty, but such an indication is still better than simply monitoring the presence of mains voltage.
Troubleshooting table, ULTRATON MS-2000,
The operability of the device is restored by replacing the failed element. The frequency of the internal oscillator of the DD1 microcircuit is regulated by the trimmer resistor R4 to the maximum voltage on the emitter BQ1.
ULTRASONIC RAT REPELLER ON CHIP KR1211EU1
(from the magazine, RADIO, No. 7 2011)
The KR1211EU1 chip is designed to build unstabilized pulse voltage converters and, in particular, to control powerful transistor switches.
It contains a master oscillator, two powerful output stages operating in antiphase, as well as control nodes.
By selecting elements of an external frequency-setting circuit, the frequency of the generated signals can be changed over a very wide range. There is also a dedicated input for turning the output signals on and off.
Thanks to the described features, this chip can be used to assemble an ultrasonic rat repeller or other harmful animals. Such devices usually emit ultrasound with a frequency of 20 ... 30 kHz in a pulsed mode or in a frequency modulation mode. This increases the effectiveness of the repeller, making it more difficult for animals to get used to the ultrasound.
The scheme of the proposed device is shown in Fig. 1
Two low-frequency pulse generators are assembled on the DD1 chip. Rectangular pulses from the output of the generator on the elements DD 1.2 and DD 1.4 are fed to the FV input of the DA1 chip and turn on at a low logic level, and turn off the signals at the outputs Q1 and Q2 of the DA1 chip at a high logic level. Therefore, the ultrasonic signal is intermittent.
The sawtooth voltage generated by the generator on the elements DD1.1 and DD1.3 is fed to the input T of the DA1 microcircuit, to which the frequency setting circuit R4C4 of its internal generator is also connected. Due to this, the frequency of the generated pulses is modulated, changing by 20...30% according to the sawtooth law. Since the generators on the DD1 chip work on different frequency, then each ultrasonic message differs in frequency from the previous one. According to the author, this makes the repeller more effective.
In order to increase the power of the device and connect an ultrasound emitter with a resistance of several ohms to it, a bridge power amplifier was used on assemblies of complementary field-effect transistors VT1 and VT2. The resistance of the open channels of these transistors is 0.05 ... 0.1 Ohm, the allowable drain current is 3 ... 4 A (constant), 12A (pulse).
The power supply voltage of the repeller must be within the limits indicated on the diagram, the current consumption depends mainly on the resistance of the emitter VA1.
The device can be assembled on a printed circuit board shown in Fig.2.
Fig.2
It is made of fiberglass, foiled on both sides. The foil on one of them serves as a common wire. Connections with it of printed conductors located on opposite side boards are made with wire jumpers. They are passed through the holes indicated on the layout of the elements with crosses.
Chip K561LE5 can be replaced by K561LA7. Switch SA1 - any small-sized. As a BA1 emitter, a high-frequency dynamic head (, tweeter,) 2GD-36 or similar from among modern ones is suitable.
When adjusting the repeller, they select resistors and capacitors of the frequency-setting circuits of all generators of the device, trying to get the most unpleasant ultrasonic signal for animals. For smooth tuning of generators, you can temporarily replace the fixed resistors with variables. By temporarily connecting another capacitor C4 with a capacity of approximately 1000 pF in parallel, it is possible to lower the frequency of ultrasonic signals and transfer them to the audible range. This will make it possible, by ear, to evaluate the parameters of the modulation.
At the moments when the output signals of the DA1 chip are turned on and off, clicks are heard in the BA1 emitter. If this is unacceptable, then it is possible to abandon the pulsed mode of operation of the microcircuit, leaving only frequency modulation of ultrasound. To do this, resistor R2 and capacitor C2 must be removed, and pins 12 and 13 of the DD1 chip must be connected to a common wire.
Photo of the printed circuit board of the device
ULTRASONIC RAT REPELLENT GENERATOR
(from the magazine. , RADIO AMATEUR, No. 7 1996)
This generator can be used in grain storage and other food storage areas.
The generator circuit shown in the figure consists of a low frequency modulator (C1, C2, DD1.1, DD1.2, R1, R2), an ultrasonic vibration generator (C3, C4, DD1.3, DD1.4, R3, R4) , a power amplifier on transistors VT1 ... VT3 and a radiator, which is used as a high-frequency loudspeaker 4GDV-1. With the ratings indicated on the diagram, the generator emits frequency-modulated oscillations in the range of 15 ... 40 kHz. The generator frequency is controlled by resistor R4, the modulation frequency is controlled by resistor R2 within 2...10 Hz.
If contact S1 is set in such a way that this contact closes in case of unauthorized entry into the room, the generator can also work as a siren burglar alarm, since it begins to radiate frequency-modulated oscillations in the range of 1000 .... 2000 Hz.
It should be borne in mind that during prolonged work in one frequency range, rats can adapt, therefore, it is necessary to change the radiation parameters with resistors R2 and R4 2 ... 3 times a week. You can also apply this technique: connect the capacitor C4 to a piece of wire that creates an additional capacitance that changes with temperature, humidity, wind strength (if the wire is brought out), etc. Then the frequency will change according to a random law.
ULTRASOUND AGAINST RODENTS
(from the magazine, RADIO AMATEUR, No. 1 2007)
The figure shows a diagram of a five-stage generator (if desired, the number of output frequencies can be increased to 10). The clock pulse generator is assembled on a DA1 chip. The frequency of the generator determines the turn-on time of the frequencies of the ultrasound generator and is determined by the parameters of the elements R1 and C1. Rectangular pulses from the output of the DA1 chip are fed to the input of a decimal counter assembled on the DD1 chip.
The high frequency generator (60 ... 80 kHz) is assembled on a DD2 chip. The frequency of the generator is determined by the parameters of the elements C2, R5, R6 and alternately connected counter DD1 resistors R6...R10. From output 3 of the DD2 microcircuit, rectangular pulses are fed to the input of the DD3 trigger, and after dividing by 2 from the output of the DD3 trigger, antiphase rectangular pulses are fed to a bridge power amplifier assembled on complementary pairs of transistors VT1, VT3 and VT2, VT4, the load of which is a high-frequency piezoelectric dynamic head.
If the device is intended for use in small spaces (a small warehouse, pantry or barn), then you can reduce the output power by abandoning the amplifier, and connect the piezoelectric emitter directly to one of the outputs of the DD3 trigger.
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Some birds, as well as dogs, mice, rats, the bats and other animals can hear sounds up to 40,000 Hz. The circuit proposed here emits continuous ultrasound at a frequency higher than that perceived by humans in the range between 18,000 and 40,000 Hz. The device can be used to treat dogs and other animals, in biological experiments and for many other purposes.
The circuit (Fig. 1) generates a signal with a frequency of 18,000 to 40,000 Hz, but you can easily change this range by selecting the capacitance of the capacitor C1 or resistor R1. The range of capacitance C1 is from 470 pF to 0.001 μF, the resistance of the resistor R1 can be increased to 100 kOhm. The upper limit of the frequencies generated by the IC 4093 is 500 kHz.
The list of elements is given in the table.
The circuit can be placed in a small plastic case. the speaker is fixed on the front panel.
Ultrasonic generator 1. This circuit operates in the frequency range from 18 to 40 kHz
Ultrasonic generator second option
Using two 4093 ICs, you can make a powerful ultrasonic generator, as shown in the figure. As a load in the circuit, a piezo speaker or a piezo earphone with tens of milliwatts is used. The generator operates in the frequency range between 18000 and 40000 Hz.
The frequency can be varied by changing the capacitance C2. The upper frequency limit of the circuit is 1 MHz.
The generator is suitable for conducting biological experiments related to the study of the behavior of animals and their conditions of detention. Power supply is four AA batteries or a 9 V battery/accumulator. The circuit consumes only a few milliamps, while the battery life is up to several weeks.
In series with R1, you can turn on a variable resistor with a nominal value of 47 kOhm, which will allow you to adjust the frequency over a wide range.
The list of elements is given in the table. As a loudspeaker, you can use a high-frequency piezo speaker - a tweeter. There is a small output transformer inside this component as shown in the picture. You need to remove it.
List of elements of the ultrasonic generator 2
Ultrasonic generator third option
This is the third version of the ultrasonic generator. A piezoelectric tweeter is used. The output stage on transistors provides a powerful output signal. The speaker, which is the load of the output stage, can produce an ultrasonic signal with a power of up to 400 mW.
The circuit is powered by four AA batteries or a 9 V battery/battery, the current consumption is about 50 mA.
The frequency can be set by resistor R1 between 18000 and 40000 Hz. You can change the frequency by selecting the capacitance of the capacitor C1. Values between 470 and 4700 pF can be adjusted experimentally.
Although the tweeter is most efficient between 10,000 and 20,000 Hz, this transducer has been experimentally proven to work well up to 40,000 Hz.
In this circuit, there is no need to disconnect the internal transformer of the tweeter, as we did in the previous project. You can also use a special ultrasonic transducer with an impedance of 4 to 100 ohms.
Schematic diagram of the ultrasonic generator is shown in the figure. The list of elements is given in the table. The device can be assembled in a small plastic case.
To adjust the frequency, use a frequency meter by connecting it to pin 4 of the IC.
This circuit can output a few watts of ultrasonic signal using a piezoelectric tweeter or other type of transducer. The operating frequency is from 18000 to 40000 Hz, it can be changed by selecting the capacitance of the capacitor C1. At high capacitance values, a signal will be generated in the audio range, which allows the circuit to be used in alarms and other devices. In this case, the tweeter can be replaced by a conventional loudspeaker.
The circuit draws several hundred milliamps from a 9 or 12 V power supply. Batteries are recommended for short-term operation only.
You can use this device to repel dogs and other animals by placing it near garbage collection areas, etc.
The ultrasonic mode of operation is achieved when the capacitance C1 is from 470 to 2200 pF. The audio range signal requires a capacitance in the range of 0.01-0.012 uF.
A schematic diagram of a powerful ultrasonic generator is shown in the figure, a list of elements is given in the table.
Powerful ultrasonic generator. All transistors must be mounted on heatsinks
Transistors must be mounted on heatsinks. All components can be placed in a plastic case
For the scheme "Generators with a stable amplitude"
Radio amateur-designer with a stable amplitude. Generator with a stable amplitude. Fig.1 The generator of harmonic signals (Fig. 1) with frequencies from 10 Hz to 100 kHz has a high amplitude stability. The stabilization of the signal amplitude is carried out using a field-effect transistor included in the PIC circuit. The field effect transistor is controlled by a constant voltage, which is formed on the capacitor C1 and amplified by the op-amp DA2. The large transfer coefficient of the op amp DA2 holds the amplitude of the harmonic signal with an accuracy of tens of millivolts in the range from 1 to 9 V. The amplitude is adjusted by the potentiometer R9. The harmonic coefficient of the output signal is less than 0.1%. Stabilization of the signal amplitude using LEDs. The gain of the op-amp (Fig. 2) is set using resistors R3 and R4 and is equal to 3.2. This gain is needed to start the generator. As soon as the amplitude of the harmonic signal increases to 1.6 V, the diodes open and an additional feedback circuit appears. Fig.2 The gain drops, and the amplitude of the harmonic oscillation stabilizes at a certain level. The distortions introduced by the stabilization circuit do not exceed 1%. The amplitude of the output signal is adjustable from 2 to 5V. The frequency depends on the elements of the Wien bridge and can take values from units of hertz to hundreds of kilohertz. Generator with automatic signal amplitude control. The generator (Fig. 3) is assembled on a VT1 field-effect transistor with a double T-shaped bridge in the OS circuit. To stabilize the amplitude of the output signal in the collectors of transistors VT2 and VT3, the oscillations are rectified by a detector assembled on elements C6, C7, VD1, VD2. At the exit...
For the scheme "NOISE GENERATORS FOR OFFICE"
For the scheme "QUARTZ GENERATORS FOR PORTABLE RADIO STATIONS"
Nodes of amateur radio equipmentQUARTZ FOR PORTABLE RADIO STATIONS When designing portable radio stations with AM and FM modulation, separate receiving and transmitting paths are often used. In addition, each of them uses its own master generator. Such a construction is convenient when setting up, but requires a significant amount of space in the structure. But since the dimensions in a portable radio station are one of the fundamental factors, the use of a combined local oscillator seems to be a promising solution to the problem of miniaturization. On fig. 1 shows a diagram of a combined local oscillator with quartz frequency stabilization. Depending on where the control voltage is applied, it generates a voltage with a frequency of either 27 or 22 MHz. The generator is made according to the capacitive three-point scheme on the transistor VT1. Quartz is included between its base and collector. Schemes on ts106-10 When a voltage of +12 V TX is applied, conditions are created for the ZQ1 quartz to be excited (the L1C3 circuit is tuned to a frequency close to 27 MHz). If a control voltage of +12 V RX is supplied, then the ZQ2 quartz is excited (the L3C3 circuit is tuned to a frequency close to 22 MHz). The output signal is taken from the collector of the transistor VT1. Load - high-resistance cascades made on field-effect transistors KP350B. The divider R1R2 for setting the gate circuit voltages is common for both stages. Coils L1, L2 are wound with PEL wire 0.24 turn to turn on frames with a diameter of 5.5 mm. L1 contains 12, L2 - 24 turns. Trimmer from SB9a. It is expedient to use the described generator when the frequency spacing of quartz is not less than 3 MHz. With a smaller spacing, you should use a generator made according to the scheme with a capacitive three-point with a capacitive divider (Fig. 2). ...
For the scheme "HIGHLY STABLE TWO-POINT GENERATOR"
Units of amateur radio equipmentHIGHLY STABLE TWO-POINT GENERATOR PETIN, 344015, Rostov-on-Don, Eremenko str., 60/6 - 247, tel. 25-42-87. Three-point generators are most often used to generate high-frequency harmonic oscillations. In some cases (for design reasons) a two-point generator may be useful. Such a generator requires the use of two transistors. However, in a properly designed two-point generator (see figure), the total number of elements may be even less than in a three-point one. Due to the fact that the signal from the oscillatory circuit LI, C2 of the generator is fed to the gate VT2, which has a large input resistance, and the feedback signal is taken from the collector VT1, which has a large output resistance, the oscillatory circuit is very weakly shunted by the electronic circuit and retains its high quality factor. In addition, to increase the input resistance of the field effect transistor VT2, a resistor R2 is included in its source circuit, to increase the output resistance of the bipolar transistor VT1, a resistor R1 is installed in its emitter circuit. For this scheme It has been experimentally determined that the frequency drift in 1 s does not exceed 1...2 Hz at a frequency of 10 MHz, i.e. The thermostat circuit on a triac short-term frequency stability of this generator is close to the frequency stability of a quartz oscillator. The long-term frequency stability is much worse, and is mainly determined by the stability of the resonant frequency of the oscillatory circuit and the supply voltage. A change in the supply voltage by 1 V leads to a frequency drift of about 1000 Hz. With the same oscillatory circuit in a three-point generator based on a bipolar transistor according to a common base circuit, the frequency drift for 1 s turned out to be about 50 Hz. With the task of increasing the frequency stability, it is desirable to select the resistance of the resistor R3, the value of which determines the depth of positive feedback. With lower...
For the scheme "REFERENCE GENERATOR"
Components of amateur radio equipmentSUPPORT GENERATORV. EGORENKOV (RA3DAV), Kaliningrad, Moscow region. For. The formation of an SSB signal is sometimes used - electromechanical filters, the frequencies of which differ from the frequencies of standard low-frequency quartz resonators by several kilohertz. Electronic tuning of quartz resonators; at low "frequencies within these limits is impossible. Such a problem can be solved by separating the beats between the oscillations of two generators stabilized by high-frequency quartz resonators. Quartz (see figure) are assembled on transistors T1 and T3. Capacitors C1 and C8 are selected to adjust the frequency of the generators. Their capacitance can range from tens to thousands of picofarads.These work well in the range of 1-10 MHz, requiring almost no tuning.A simple thermostat on a triac In many cases, the chokes Dr1 and Dr3 can be replaced by resistors with a resistance of 2-6k. frequencies of 501.7 kHz, quartz resonators Kv1 7.0 and Kv2 7.5 MHz were used. The frequency stability depends mainly on the stability of the supply voltage. When the supply voltage changed by ± 1 V, the frequency changed by ± 40 Hz (control was carried out by an electronic frequency meter Ch3 -12).The mixer is made on the transistor T2.The capacitor C5 is selected according to the minimum non-linear distortion, controlling you input voltage with an oscilloscope. Coils L1 and L2 are wound on the SB-12a core and have 100 and 20 turns of PEL 0.1 wire, respectively. assembled on transistor T4). For a frequency of 22.5 MHz, the L3 coil has 6 turns of PEL wire 0.8, the frame diameter is ...
For the circuit "Electronic interrupter simulator"
The simulator is designed to test the electronic switches of the automotive ignition system using the oscilloscope method. To test the switch, it is necessary to apply rectangular pulses to its input with a duty cycle of approximately three and a repetition rate of 33 or 100 Hz. This corresponds to the rotation of the crankshaft of a four-cylinder engine at a frequency of 500 and 1500 rpm. Depending on the speed of the shaft, the duty cycle of the pulses at the output of the switch should change. Many radio amateurs have acquired oscilloscopes, but not everyone has the necessary generators. In the proposed device, rectangular pulses are generated by a multivibrator on transistors VT1 and VT2, which are fed to the key - transistor VT3. The collector VT3 of the simulator is connected to the terminal 7G of the switch. Instead of an ignition coil, as a load, you can connect an A12-45 + 40 (EL1) car lamp or a lamp close to it in power. The generator frequency is set by switch SA1. It is possible to detect malfunctions in the switch by comparing the voltage oscillograms at the control points of the "naughty" switch with the serviceable one. Using the SB1 button, the current is turned off through the ignition coil when the engine is stopped. When the button is pressed, the lamp should go out after a few seconds. P. SEVASTYANOV, Tashkent, Uzbekistan ....
For the circuit "HF generator on LF quartz"
Nodes of amateur radio equipmentHF generator on low-frequency quartz V. LENSKY, Krasnodar Due to the lack of high-frequency quartz to obtain highly stable oscillations in HF and VK In the ranges, radio amateurs often resort to multiplying low-frequency oscillations of the exciter. This complicates the scheme of the device, reduces its efficiency, increases the size and weight. These shortcomings can be eliminated by direct excitation of low-frequency quartz at odd mechanical harmonics. When excitation of quartz at mechanical harmonics, one should take into account the harmful effect of static capacitance (quartz holder and circuit elements) shunting quartz. Due to this capacitance, the activity of the quartz resonator rapidly decreases with increasing harmonic number. Therefore, excitation at harmonics above the fifth can only be with compensation or neutralization of static capacitance. Compensation generators, due to their tendency to self-excitation and the complexity of restructuring when changing the harmonic number, are not of particular interest to radio amateurs. Turn relay on the thyristor of the circuit It is more expedient to use the neutralization of static capacitance by placing quartz in one of the arms of the balanced bridge. Bridge harmonic quartz have a number interesting features. They have range properties - they allow excitation at various odd mechanical harmonics. For such a restructuring, it is enough to change the frequency of the circuit. When the static capacitance is neutralized, the quality factor of quartz increases with increasing harmonic number, reaches a maximum, and then gradually decreases. The power of the generated oscillations varies slightly with increasing serial number harmonics. Bridges have...
For the scheme "Using ultrasound"
Consumer Electronics Use Use ultrasound- this is another direction in the development of "Proximity Detectors". Figure 1 shows how such a device works. The top of the figure shows a possible configuration when the transmitter and receiver ultrasound abides opposite a friend of a friend. As long as nothing prevents the ultrasound from fully reaching the receiver, the circuit is on hold. And just the intruder, located between the emitter and the receiver, can prevent this. Options for ultrasonic burglar alarms Such a device is able to provide a very high level of reliability. After all, any decrease in the signal level from the transmitter or even the termination of its operation in general will be regarded by the receiver circuits as a danger. The above examples may appear simply when the transmitter is disabled. Another effective receiver and transmitter arrangement is shown at the bottom of the figure. Scheme of a simple radio transmitter for 6p45s In this case, ultrasound is reflected from a solid object at a distance and enters the receiver. The signal emitted by the transmitter must be quite strong. Naturally, every object that gets in the way of the sound will trigger an alarm. Another way of operating the device is possible. In this case, the sound reaches the receiver only by bouncing off the burglar in the vicinity of the transmitter and receiver. All of the methods described are good, so choose the one that best suits your conditions. Ultrasonic Watchman with Separate Receiver and Transmitter Figure 1 is a schematic diagram of an ultrasonic transmitter. It is based on a 555 type timer, and the operating frequency is determined by the values of the resistors R1 and R4 and the capacitor C1. ...
To make an ultrasonic generator, you need to additionally purchase two rectangular pulse generators, but also pre-develop a power amplifier according to the classical bridge circuit. In addition, it is necessary to further develop circuit diagram, along which further assembly of the ultrasound device will be carried out. Yes, in electrical circuit there must be resistors to control the sound frequency, capacitors to smoothly change the output frequency, field-effect transistors as part of the bridge circuit, inverters to continue the sound, a choke to rectify the current, and a power supply to supply the operating voltage to the electrical circuit. To a simple layman such a task, alas, is beyond the power, therefore, when drawing up a diagram and carrying out additional calculations, it still does not hurt to first consult with a professional.
There are two types of schemes for creating an ultrasonic generator: with the presence of a transformer and without its participation. The principal circuits are different, however, in both cases, the finished device functions properly and perfectly copes with its direct duties - generating sound of various frequencies. In the first version, the electrical circuit does not contain a transformer, and the push-pull driver chip LDS KF1211EU1 becomes the source of the main signal. It is from it that the signal comes out and immediately goes to the key drivers, which, in turn, are controlled according to the principle of a transistor bridge. A timer is additionally introduced into the circuit, connected to a control button, which works according to classical principle"On off". The mains voltage after assembling such a design can reach 500 V according to direct current, while the power of a homemade generator is constantly increasing.
If the operating voltage is too high, it can be corrected using resistors that lower it by introducing additional resistance into the circuit diagram. The main thing here is correct given parameters specific circuit to determine the type of such a part, otherwise, out of ignorance, the finished mechanism will burn out from increased voltage. Additional resistance is calculated according to Ohm's law for an alternating current circuit. In addition, approximate physical calculations in the examples can always be found on the worldwide web - on specialized radio amateur sites. In this case, it is better not to experiment with increased voltage: The ultrasonic generator can be permanently damaged in this way. Moreover, a circuit diagram is known that functions perfectly at an operating voltage of 35 V. It is also easy to reproduce it at home, the main thing is to prepare the required materials.
To make an ultrasonic generator for a voltage of 35 V, it is recommended to take as a basis printed circuit board made of textolite or fiberglass. The lower component of the board will be the screen and wire, and the wiring diagram can be viewed on the Internet for clarity. According to the scheme, collect all the required elements, and finished structure Finally varnished. Making such a device will not be easy for a person who has nothing to do with electrical and radio engineering. So this one important point it is also important to take note so that in the absence of the required "baggage of knowledge" do not waste precious time.
Modern man clearly understands how important and irreplaceable an ultrasonic generator is in everyday life; that is why he tries to get it for personal use. A wide range of models is presented in specialized stores, but the cost of such copies starts from 10,000 rubles. In general, this is a profitable purchase if you constantly use it for its intended purpose. In the absence of the declared amount, it is quite realistic to build such a structure at home, but first find the manufacturing instructions, understand the principle of operation of this complex mechanism and determine its feasibility in a particular case. If the device is really needed, then without the help of a specialist, certain difficulties will arise in the process of its development.
