Do-it-yourself powerful ultrasonic gun. Yagma Medical Physics High Wave Impedance Devices

MODERNIZED ULTRASONIC GUN "IGLA-M"

Have a ltrasound are elastic waves of high frequency. Usually, the ultrasonic range is considered to be the frequency range from 20,000 to several billion hertz. Now ultrasound is widely used in various physical and technological methods. The fact that ultrasound actively affects biological objects (for example, kills bacteria) has been known for over 70 years. Electronic equipment with a scanning ultrasound beam is used in neurosurgery to inactivate individual areas of the brain with a powerful focused high-frequency beam. High-frequency vibrations cause internal tissue heating.

Until now, there are discussions about the physical effect of ultrasonic vibrations on the cell and even about the possible disruption of DNA structures. Moreover, there is evidence that at the micro level - not at the level of the structure of the body, but at some more subtle level, ultrasonic exposure turns out to be harmful.

Ultrasound can be obtained from mechanical, electromagnetic and thermal sources. Mechanical emitters are usually all sorts of intermittent sirens. They emit vibrations into the air with a power of up to several kilowatts at frequencies up to 40 kHz. Ultrasonic waves in liquids and solids are usually excited by electro-acoustic, magnetostrictive, and piezoelectric transducers.

The industry has long been making devices forultrasonic effects on animals, for example:

Appointment

A miniature dog repeller is a wearable electronic device (assembled in a mini-flashlight housing) that emits ultrasonic vibrations that are audible to dogs and not perceived by humans.

Operating principle

The device is designed to protect against attacks from dogs: ultrasonic radiation of a certain power usually stops an aggressive dog at a distance of 3 to 5 meters or makes it flee. The greatest effect is achieved when exposed to aggressive stray dogs.

Specifications

• Supply voltage (1 battery type 6F22 (KRONA)), V 9
• Consumption current, not more, A 0.15
• Weight with batteries, no more, g 90

As you can imagine, this is a weak toy, but we will make the device much more powerful! Continuing the experiments with ultrasound (), a number of interesting improvements and improvements were made. Thus, a revolutionary method of exposure (naturally negative) was produced on a living organism of two ultrasonicemitters with a difference frequency of several hertz. That is, the frequency of one emitter, for example, 20,000 Hz, and the other, 20010 Hz. As a result, onultrasonic radiation superimposed infRazvukovoe, which greatly enhances the destructive effect!

The circuit is standard, a generator on CD4069 + an amplifier on three N-P-N transistors. Power supply not less than 12 V, at current up to 1 A.

To enhance the directional effect, we use cylindrical sound resonators. Their role will be played by an ordinary nickel-plated tube from a vacuum cleaner.Just do not spoil the vacuum cleaner, the tube is sold separately at the bazaar or in the spare parts store.

We cut two pieces to an experimentally determined length (about a couple of centimeters), and attach them to HF heads of the 5GDV-4 type or any others. You can buy a double nozzle for a car exhaust pipe, the installation is much more convenient, and the effect will be even better.

We insert the high-frequency speakers inside, and in the back we mount the board with the battery.

Returning from work at night or wandering through dark alleys, there is a danger of being attacked by stray dogs, whose bites are sometimes life-threatening, if you do not see a doctor in time. It was for these cases that smart human brains came up with an ultrasonic repeller.

Industrial repellents have a rather complex scheme and are made on rather scarce components.

In this article we will consider a variant of such a repeller using the famous 555 timer series. The timer, as you know, can work as a generator of rectangular pulses, it is this connection that is used in the circuit.

The generator operates at a frequency of 20-22 kHz, as you know, many animals "communicate" in the ultrasonic range. Experiments have shown that frequencies of 20-25 kHz cause artificial fear in dogs, thanks to the tuning regulator, the generator can be tuned to a frequency of 17-27 kHz.

The circuit itself contains only 6 components and will not cause any difficulties. It is advisable to use a multi-turn regulator for more accurate tuning to the desired frequency.
The piezo emitter can be taken from a calculator or any other musical toys, you can also use any HF heads with a power of up to 5 watts, there is simply no point anymore.

The device works effectively at a distance of 3-5 meters, since there is no additional power amplifier in the circuit.

As a power source, it is convenient to use a crown, or any other source with a voltage of 6 to 12 volts.

List of radioelements

Designation	A type	Denomination	Quantity	Note	Score	My notebook
	Programmable timer and oscillator	NE555	1			Into notepad
R1	Resistor	2.2 k Ohm	1			Into notepad
R2	Resistor	1 kΩ	1			Into notepad
R3	Variable resistor	4.7 k Ohm	1			Into notepad
C1	Electrolytic capacitor	10 μF	1			Into notepad
C2	Capacitor	10 nF	1			Into notepad
	Piezo emitter		1

Ultrasonic Shocker Emitter

Active alarm actuator

This device is intended for demonstration testing in a laboratory environment only. The company is not responsible for any use of this device.

A limited deterrent effect is achieved by exposure to powerful ultrasonic radiation. At strong intensities, ultrasonic vibrations have an extremely unpleasant, irritating and painful effect on most people, causing severe headaches, disorientation, intracranial pain, paranoia, nausea, indigestion, and a feeling of complete discomfort.

The ultrasonic frequency generator is made on D2. The multivibrator D1 generates a triangular signal that controls the sweep of the D2 frequency. Modulation frequency 6-9 Hz lies in the area of ​​resonances of internal organs.

D1, D2 - KR1006VI1; VD1, VD2 - KD209; VT1 - KT3107; VT2 - KT827; VT3 - KT805; R12 - 10 Ohm;

T1 is made on a ferrite ring М1500НМЗ 28x16x9, windings n1, n2 each contain 50 turns D 0.5.

Disable the emitter; disconnect resistor R10 from capacitor C1; with a trimmer resistor R9 set to pin. 3 D2 frequency 17-20 kHz. Resistor R8 set the required modulation frequency (pin. 3 D1). The modulation frequency can be reduced to 1 Hz by increasing the capacitance of the capacitor C4 to 10 μF; Connect R10 to C1; Connect the emitter. Transistor VT2 (VT3) is installed on a powerful radiator.

As an emitter, it is best to use a specialized piezoceramic head BA of imported or domestic production, which provides a sound intensity level of 110 dB at a nominal supply voltage of 12 V: You can use several powerful high-frequency dynamic heads (speakers) BA1 ... BAN, connected in parallel. To select a head, based on the required ultrasound intensity and distance of action, the following technique is proposed.

The average electric power supplied to the speaker Рср = Е2 / 2R, W, should not exceed the maximum (passport) power of the head Рmax, W; E - signal amplitude at the head (meander), V; R is the electrical resistance of the head, Ohm. In this case, the effectively supplied electric power to the radiation of the first harmonic is Р1 = 0.4 Рav, W; sound pressure Psv1 = SdP11 / 2 / d, Pa; d is the distance from the center of the head, m; Sd = S0. 10 (LSd / 20) Pa W-1/2; LSd - level of characteristic sensitivity of the head (passport value), dB; S0 = 2. 10-5 Pa W-1/2. As a result, the sound intensity I = Npsv12 / 2sv, W / m2; N is the number of parallel-connected heads, s = 1.293 kg / m3 is the air density; v = 331 m / s is the speed of sound in air. Sound intensity level L1 = 10 log (I / I0), dB, I0 = 10-12 I m / m2.

The level of pain threshold is considered equal to 120 dB, rupture of the tympanic membrane occurs at an intensity level of 150 dB, destruction of the ear at 160 dB (180 dB burns through the paper). Similar foreign products emit ultrasound with a level of 105-130 dB at a distance of 1 m.

When using dynamic drivers, it may be necessary to increase the supply voltage to obtain the required intensity level. With an appropriate heatsink (needle with an overall area of ​​2 dm2), the KT827 transistor (metal case) allows the parallel connection of eight dynamic heads with a coil resistance of 8 0m each. 3GDV-1; 6GDV-4; 10GI-1-8.

Different people tolerate ultrasound in different ways. Young people are most sensitive to ultrasound. It's a matter of taste if you choose powerful sound radiation instead of ultrasound. To do this, it is necessary to increase the capacity of C2 tenfold. If desired, you can turn off the frequency modulation by disconnecting R10 from C1.

With increasing frequency, the radiation efficiency of some types of modern piezoelectric emitters increases sharply. With continuous operation for more than 10 minutes, overheating and destruction of the piezoelectric crystal is possible. Therefore, it is recommended to choose a supply voltage lower than the nominal one. The required level of sound intensity is achieved by switching on several emitters.

Ultrasonic emitters have a narrow directivity pattern. When using an actuator for the protection of large rooms, the emitter is aimed in the direction of the alleged intrusion.

Taken from http://patlah.ru/etm/etm-11/e-shokeri/e-shokeri/e-shok-09.html

"Encyclopedia of Technologies and Techniques" Patlakh V.V. 1993-2007

Medical Faculty

1 course

1 semester

1 stream

Lecture number 5

"Ultrasound"

Compiled by: Babenko N.I.

2010 r.

Ultrasound and its receipt. Ultrasound emitters.

Ultrasound is mechanical vibrations with a frequency of more than 20,000 Hz, which propagate in elastic media in the form of longitudinal waves. Sources of ultrasound are:

1. Natural:

2. Artificial:

acousto-mechanical transducers;

electroacoustic transducers (piezoelectric, magnetostrictive).

Natural sources of ultrasound are sources not created by human hands and independently existing in nature.

Live springs: grasshoppers, crickets, fish, bats, dolphins. Inanimate sources: wind, landslides in the mountains, earthquakes.

Artificial sources of ultrasound are called acoustic transducers because they convert mechanical or electrical energy into the energy of ultrasonic vibrations.

Acoustic-mechanical transducers are transducers in which ultrasonic vibrations occur when the flow of a liquid or gas is interrupted. Examples: Galton whistle, ultrasonic siren.

Electroacoustic transducers are transducers in which ultrasonic vibrations occur when some substances are acted upon by alternating electric or magnetic fields.

Piezoelectric transducers (piezo - pressure) are transducers that use the phenomenon of the inverse piezoelectric effect to obtain ultrasound.

The piezo effect can be direct and inverse.

The direct piezoelectric effect consists in the appearance of charges on the surface of some crystals (piezodielectrics) under the action of mechanical stress (compression, tension, bending). Fig. 1.

With direct piezoelectric effect:

the amount of charge on the surface is proportional to the applied mechanical stress;

the sign of the charge is determined by the direction of the mechanical action.

no impact compression tension

The inverse piezoelectric effect is the phenomenon of a change in the size (deformation) of a dielectric when it is placed in an alternating electric field.

Substances with pronounced piezoelectric properties are called piezoelectrics or piezodielectrics: Rochelle salt, barium titanate, quartz.

Magnetostrictive transducers are transducers that use the phenomenon of magnetostriction to generate ultrasound. Magnetostriction is the phenomenon of a change in the shape (size) of some ferromagnetic substances under the influence of an alternating magnetic field.

These substances include:

Nickel and its alloys;

Cobalt and its alloys;

Ferrites are ceramic compounds based on oxides of iron, nickel, zinc.

A substance in the form of a rod is placed inside the coil. When the coil is connected to a source of alternating electric voltage of ultrasonic frequency, the electric current acts on the rod with its magnetic component and causes its deformation (elongation) at the current frequency. Fig. 2

A few days ago I received another order. The buyer wanted to order a powerful ultrasonic cannon to combat drunken youth, for whom the day begins at night when all normal people are asleep. Without thinking twice, I chose a proven scheme of a powerful ultrasonic emitter. The gun itself is built on just one standard logic microcircuit.

Literally any similar microcircuit containing 6 logic inverters will do. In our case, a CD4049 (HEF4049) microcircuit was used, which can be successfully replaced with a domestic one - K561LN2, only you need to pay attention to the pinout, since K561LN2 differs from the one used by some conclusions.

Since the circuit is quite simple, it can be implemented on a breadboard or in a hinged manner. The amplifier is assembled on complementary pairs of KT816 / 817, due to the use of these keys, the power of our gun is 10-12 watts.

As an emitter, it is desirable to use high-frequency heads of the 10 GDV type or import; it is not advisable to use a piezo emitter.

The case - from a Chinese electronic transformer 10-50 watts, had to be redone, since the board did not fit.

The 1.5nF capacitor is responsible for the frequency (which was then replaced by 3.9 nF, since with the capacitor indicated in the circuit, the lower frequency limit is exactly 20kHz, and with such a replacement, the frequency can be adjusted within 10-30kHz) and a variable resistor (as a result, the setting do by rotating this resistor).

Base resistors can be replaced with 2.2k ohm resistors, which are more common than those shown in the diagram. This emitter is powered by a stabilized 5 Volt power supply with a current of 1 A (supply voltage range of 3.7-9 Volts).