Simple patterns for beginners. Unusual sounds simulator Professional sound simulator

Some of the parts are mounted on a printed circuit board (Fig. 48), which is then placed inside a suitable housing. The battery is also installed there. The dynamic head and switch can be mounted on the front wall of the case.

If all parts are in good working order and installed without errors, the simulator does not require any adjustment. Nevertheless, remember the following recommendations. The repetition frequency of trills can be changed by selecting resistor R5. Resistor R7, connected in series with the head, affects not only the sound volume, but also the frequency of the blocking oscillator. This resistor can be selected experimentally, temporarily replacing it with a variable wire resistor with a resistance of 2...3 Ohms. When achieving the highest sound volume, do not forget that distortion may appear, deteriorating the sound quality.

Rice. 48. Simulator circuit board
When repeating this simulator, in order to obtain the desired sound, it was necessary to slightly change the values of the parts and even rebuild the circuit. Here, for example, are the changes made to one of the designs. The chain C4, C5, R6 is replaced by a capacitor (oxide or other type) with a capacity of 2 μF, and instead of resistor R5, a chain of a series-connected constant resistor with a resistance of 33 kOhm and a trimmer resistor of 100 kOhm is included. Instead of the chain R2, C2, a capacitor with a capacity of 30 μF is included. Resistor R4 remained connected to the terminal of inductor L1, and between the terminal and the base of transistor VT2 (and therefore the positive terminal of capacitor C1) a resistor with a resistance of 1 kOhm was connected, and at the same time a resistor with a resistance of 100 kOhm was connected between the base and emitter of transistor VT2. In this case, the resistance of resistor R2 is reduced to 75 kOhm, and the capacitance of capacitor C1 is increased to 100 μF.

Such changes can be caused by the use of specific transistors, a transformer and inductor, a dynamic head, and other parts. Listing them makes it possible to experiment more widely with this simulator to obtain the desired sound.

In any case, the functionality of the simulator is maintained when the supply voltage changes from 6 to 9 V.
^ TRILLS OF THE NIGHTINGALE
Using part of the previous design, you can assemble a new simulator (Fig. 49) - the trill of a nightingale. It contains only one transistor, on which a blocking oscillator is made with two positive circuits feedback. One of them, consisting of inductor L1 and capacitor C2, determines the tonality of the sound, and the second, composed of resistors Rl, R2 and capacitor C1, determines the trill repetition period. Resistors Rl - R3 determine the operating mode of the transistor.

^ Rice. 49. Circuit of a nightingale trill simulator on one transistor
The output transformer, inductor and dynamic head are the same as in the previous design, the transistor is of the MP39 - MP42 series with the highest possible current transfer coefficient. Power source - any (from galvanic batteries or rectifier) with a voltage of 9... 12 V. Resistors - MLT-0.25, oxide capacitors - K50-6, capacitor SZ - MBM or another.

There are few parts in the simulator and you can arrange them yourself on a board made of insulating material. The relative position of the parts does not matter. Installation can be either printed or mounted, using racks for parts leads.

The sound of a simple simulator largely depends on the parameters of the transistor used. Therefore, setting up comes down to selecting parts to obtain the desired effect.

The tone of the sound is set by selecting the capacitor SZ (its capacity can be in the range from 4.7 to 33 µF), and the desired duration of the trills is by selecting resistor R1 (ranging from 47 to 100 kOhm) and capacitor C1 (from 0.022 to 0.047 µF). The plausibility of the sound largely depends on the operating mode of the transistor, which is set by selecting resistor R3 in the range from 3.3 to 10 kOhm. The setup will be greatly simplified if, instead of constant resistors R1 and R3, variables are temporarily installed with a resistance of 100 - 220 kOhm (R1) and 10 - 15 kOhm (R3).

If you want to use the simulator as a doorbell or sound alarm, replace the capacitor SZ with another, larger capacity (up to 2000 µF). Then, even with a short-term supply of power to the bell button, the capacitor will instantly charge and act as a battery, allowing you to maintain a sufficient duration of sound.

A diagram of a more complex simulator, which requires virtually no setup, is shown in Fig. 50. It consists of three symmetrical multivibrators that produce oscillations different frequencies. Let's say the first multivibrator, made on transistors VT1 and VT2, operates at a frequency of less than a hertz, the second multivibrator (it is made on transistors VT3, VT4) - at a frequency of several hertz, and the third (on transistors VT5, VT6) - at a frequency of more than a kilohertz. Since the third multivibrator is connected to the second, and the second to the first, the oscillations of the third multivibrator will be bursts of signals of different durations and slightly varying frequencies. These “bursts” are amplified by a cascade on the transistor VT7 and are fed through the output transformer T1 to the dynamic head BA1 - it converts the “bursts” of the electrical signal into the sounds of a nightingale trill.

Note that to obtain the required simulation, an integrating circuit R5C3 is installed between the first and second multivibrators, which allows “converting” the pulse voltage of the multivibrator into a smoothly rising and falling one, and between the second and third multivibrators a differentiating circuit C6R10 is connected, providing a shorter duration control voltage compared to with a prominent resistor R9.

The simulator can operate transistors of the MP39 - MP42 series with the highest possible current transfer coefficient. Fixed resistors - MLT-0.25, oxide capacitors - K50-6, other capacitors - MBM or other small-sized ones. Transformer - output from any transistor receiver with a push-pull power amplifier. Half of the primary winding of the transformer is connected to the collector circuit of the transistor. Dynamic head - any low-power one, for example 0.1GD-6, 0.25GD-19. Power source - 3336 battery, switch - any design.

Rice. 50. Circuit of a nightingale trill simulator using six transistors
Some of the simulator parts are placed on a board (Fig. 51), which is then installed in a housing made of any material and suitable dimensions. A power source is placed inside the case, and a dynamic head is mounted on the front wall. You can also place a power switch here (when using the simulator as an apartment bell, instead of a switch, connect the bell button located at the front door with wires).

^ Rice. 51. Simulator circuit board
Testing the simulator begins with the third multivibrator. Temporarily connect the upper terminals of the resistors R12, R13 to the negative power wire. A continuous sound of a certain tone should be heard in the dynamic head. If you need to change the tone, just select capacitors C7, C8 or resistors R12, R13.

Then restore the previous connection of resistors R12, R13 and connect the upper terminals of resistors R7, R8 to the negative wire. The sound should become intermittent, but not yet similar to the singing of a nightingale.

If this is the case, remove the jumper between resistors R7, R8 and the negative wire. Now a sound similar to a nightingale trill should appear. A more accurate sound of the simulator can be achieved by selecting parts of the frequency-setting circuits of the first two multivibrators - base resistors and feedback capacitors.
^ FOR DIFFERENT VOICES
Some rearrangement of the circuit of the electronic “canary” - and now a circuit appears (Fig. 52) of another simulator, capable of producing the sounds of a wide variety of feathered inhabitants of the forest. Moreover, adjusting the simulator to a particular sound is relatively simple - just move the handle of one or two switches to the appropriate position.

As in the electronic “canary”, both transistors operate in a multivibrator, and VT2 is also part of the blocking oscillator. The frequency-setting circuits of the simulator include sets of capacitors of different capacities, which can be connected using switches: using switch SA1, the tonality of the sound is changed, and using SA2, the repetition frequency of trills is changed.

In addition to those indicated in the diagram, other low-power germanium transistors can operate with the highest possible transmission coefficient (but not less than 30). Oxide capacitors - K50-6, the rest - MBM, KLS or other small-sized ones. All resistors are MLT-0.25 (MLT-0.125 is possible). The choke, output transformer and dynamic head are the same as in the “canary”. Switches - any design. Suitable, for example, are 11P2N biscuit switches (11 positions, 2 directions - it is made up of two boards with contacts connected by one axis). Although such a switch has 11 positions, it is not difficult to bring them to the required six by moving the limiter (it is located on the switch handle under the nut) into the corresponding hole in the base.

Rice. 52. Scheme of a universal trill simulator

Rice. 53. Simulator circuit board
Some parts are mounted on a printed circuit board (Fig. 53). The transformer and inductor are attached to the board with metal clamps or glued. The board is installed in a housing, on the front wall of which switches and a power switch are fixed. The dynamic head can also be placed on this wall, but good results are obtained by mounting it on one of the side walls. In any case, a hole is cut out opposite the Diffuser and covered from the inside of the body with a loose fabric (preferably radio fabric), and from the outside with a decorative overlay. The power source is secured at the bottom of the Housing with a metal clamp.

The simulator should start working immediately after turning on the power (if, of course, the parts are in good condition and the installation is not messed up). It happens that due to the low transmission coefficient of the transistors, the sound does not appear at all or the simulator operates unstable. The best way in this case, increase the supply voltage by connecting another 3336 battery in series with the existing one.
^ HOW DOES A CRICK CLICK?
The cricket chirping simulator (Fig. 54) consists of a multivibrator and an RC oscillator. The multivibrator is assembled using transistors VT1 and VT2. Negative pulses of the multivibrator (when transistor VT2 closes) are supplied through diode VD1 to capacitor C4, which is the “battery” of the bias voltage for the generator transistor.

The generator, as you can see, is assembled on just one transistor and produces sinusoidal oscillations of audio frequency. This is a tone generator. Oscillations arise due to the action of positive feedback between the collector and the base of the transistor due to the inclusion between them of a phase-shifting chain of capacitors C5 - C7 and resistors R7 - R9. This chain is also frequency-setting - the frequency generated by the generator, and therefore the tone of the sound reproduced by the dynamic head BA1, depends on the ratings of its parts - it is connected to the collector circuit of the transistor through the output transformer T1.

During the open state of transistor VT2 of the multivibrator, capacitor C4 is discharged, and there is practically no bias voltage at the base of transistor VT3. The generator does not work, there is no sound from the dynamic head.

Rice. 54. Cricket sound simulator circuit

Rice. 55. Simulator circuit board
When transistor VT2 closes, capacitor C4 begins to charge through resistor R4 and diode VD1. At a certain voltage at the terminals of this capacitor, transistor VT3 opens so much that the generator begins to work, and a sound appears in the dynamic head, the frequency and volume of which changes as the voltage across the capacitor increases.

As soon as transistor VT2 opens again, capacitor C4 begins to discharge (through resistors R5, R6, R9 and the emitter junction circuit of transistor VT3), the sound volume drops, and then the sound disappears.

The repetition frequency of the trills depends on the frequency of the multivibrator. The simulator is powered from source GB1, the voltage of which can be 8...I V. To isolate the multivibrator from the generator, a filter R5C1 is installed between them, and to protect the power source from generator signals, capacitor C9 is connected in parallel with the source. When using the simulator for a long time, it must be powered from a rectifier.

Transistors VT1, VT2 can be of the MP39 - MP42 series, and VT3 - MP25, MP26 with any letter index, but with a transmission coefficient of at least 50. Oxide capacitors - K50-6, the rest - MBM, BMT or other small-sized ones. Fixed resistors - MLT-0.25, trimmer R7 - SPZ-16. Diode - any low-power silicon. The output transformer is from any small-sized transistor receiver (half of the primary winding is used), the dynamic head is 0.1 - 1 W with a voice coil with a resistance of 6 - 10 Ohms. The power source is two 3336 batteries connected in series or six 373 cells.

The simulator parts (except for the dynamic head, switch and power supply) are mounted on a printed circuit board (Fig. 55). It can then be mounted in a case, inside which the power supply is located, and on the front panel - the dynamic head and power switch.

Before turning on the simulator, set the trimmer resistor R7 to the lowest position according to the diagram. Apply power to switch SA1 and listen to the sound of the simulator. Make it more similar to the chirping of a cricket with trimming resistor R7.

If there is no sound after turning on the power, check the operation of each node separately. First, disconnect the left terminal of resistor R6 from parts VD1, C4 and connect it to the negative power wire. A single-tone sound should be heard in the dynamic head. If it is not there, check the installation of the generator and its parts (primarily the transistor). To check the operation of the multivibrator, it is enough to connect high-impedance headphones (TON-1, TON-2) in parallel with resistor R4 or the terminals of transistor VT2 (through a capacitor with a capacity of 0.1 μF). When the multivibrator is working, clicks will be heard in the phones, following after 1...2 s. If they are not there, look for an installation error or a faulty part.

Having achieved the operation of the generator and multivibrator separately, restore the connection of resistor R6 with diode VD1 and capacitor C4 and make sure that the simulator is working.
^ WHO SAID “MEOW”!
This sound came from a small box, inside of which was an electronic simulator. Its circuit (Fig. 56) is a bit reminiscent of the previous simulator, not counting the amplification part - an analog integrated circuit is used here.

^ Rice. 56. Scheme of the “meow” sound simulator
An asymmetrical multivibrator is assembled using transistors VT1 and VT2. It produces rectangular pulses, following at a relatively low frequency - 0.3 Hz. These pulses are supplied to the integrating circuit R5C3, as a result of which a signal with a smoothly increasing and smoothly decreasing envelope is formed at the terminals of the capacitor. So, when the transistor VT2 of the multivibrator closes, the capacitor begins to charge through resistors R4 and R5, and when the transistor opens, the capacitor is discharged through resistor R5 and the collector-emitter section of transistor VT2.

From the capacitor SZ, the signal is sent to a generator made on transistor VT3. While the capacitor is discharged, the generator does not work. As soon as a positive pulse appears and the capacitor is charged to a certain voltage, the generator “triggers” and an audio frequency signal (approximately 800 Hz) appears at its load (resistor R9). As the voltage across the capacitor SZ increases, and therefore the bias voltage at the base of the transistor VT3, the amplitude of oscillations at the resistor R9 increases. At the end of the pulse, as the capacitor discharges, the amplitude of the signal drops, and soon the generator stops working. This is repeated with each pulse removed from the load resistor R4 of the multivibrator arm.

The signal from resistor R9 goes through capacitor C7 to variable resistor R10 - the volume control, and from its engine to the audio power amplifier. The use of a ready-made amplifier in an integrated design made it possible to significantly reduce the size of the design, simplify its setup and ensure sufficient sound volume - after all, the amplifier develops a power of about 0.5 W at the specified load (BA1 dynamic head). “Meow” sounds are heard from the dynamic head.

Transistors can be any from the KT315 series, but with a transmission coefficient of at least 50. Instead of the K174UN4B. microcircuit (former designation K1US744B), you can use K174UN4A, which will increase slightly output power. Oxide capacitors - K53-1A (C1, C2, C7, C9); K52-1 (NW, S8, S10); K50-6 is also suitable for a rated voltage of at least 10 V; the remaining capacitors (C4 - C6) are KM-6 or other small ones. Fixed resistors - MLT-0.25 (or MLT-0.125), variable - SPZ-19a or another similar one.

Dynamic head - power 0.5 - 1 W with voice coil resistance 4 - 10 Ohms. But it should be taken into account that the lower the resistance of the voice coil, the greater the amplifier power that can be obtained from the dynamic head. The power source is two 3336 batteries or six 343 cells connected in series. Power switch - any Design.

“Based on the developments published in the magazine “Modelist-Constructor”, I built myself a photoelectronic shooting range. Works flawlessly. It’s a pity that the circuit does not provide for imitation of sounds. Help!". The sound of machine gun fire, the screech of mines, the heavy bass of land mines... A fairly simple device made with only three transistors imitates a similar sound picture of a battle.

As can be seen from the circuit diagram, the simulator of battle sounds consists of a self-exciting pulse generator - a multivibrator on transistors VT1 and VT2, an amplifier (semiconductor triode VT3) and a dynamic head BA1. And they choose sound effects the users themselves by pressing certain control buttons.

To simplify the design, one common generator is used, the operating mode of which is changed by appropriate switching. In the “machine gun” mode, this multivibrator receives power directly from battery GB1 through switches S4 (it turns on the simulator) and S1, which (thanks to contacts S1.2, S1.3) in parallel with capacitors C5, C7 connects relatively larger electrical capacitances C3 and C6 than a “queue” is provided with a certain frequency of “shots”. If desired, you can, by adjusting the value of capacitors C3 and C6, change the frequency with which the machine gun “scraps.” The current value of the transistor VTZ, indicated in the diagram, is set by selecting resistor R5.

When simulating the passage of a mine, power is supplied from a pre-charged capacitor C1 when the moving contact of the switch group S2.1 is moved to the right position according to the diagram. At the same time, capacitor C4 is connected to the multivibrator arm by group S2.2. As capacitor C1 discharges, the voltage on the multivibrator smoothly decreases, while the generated frequency increases and a sound appears, reminiscent of the screech of a flying mine.

The organization of power supply to the multivibrator in the “rocket” mode is similar - from capacitor C2 through switch s3. In this case, only capacitors C5 and C7 work in the arms of the multivibrator. The sound, starting from a low note, gradually rises to a very high note and seems to disappear into the distance.

Simulation signals are amplified in cascade on transistor VT3, connected according to a common emitter circuit. Its load is the dynamic head BA1 in the collector circuit of transformer T1.

The simulator's power source is a Corundum battery or two 3336 cells connected in series. It is possible to use a network unit (adapter). For switches S1-S3, it is better to use buttons or toggle switches with self-return to their original position. A knife-type band switch from a portable radio can also be used as S1. Automatic return to the open state will be ensured here if the switch handle is equipped with a spiral spring.

The circuit board of the simulator is made of foil fiberglass laminate. The corresponding oxide capacitors K50-6 or MBM (C4), KLS (C1-SZ, C5-C8), resistors (all of them are MYAT type, with a power of no more than 0.5 W) and other elements of the fundamental circuit are soldered to its “printed” pads. electrical circuit.

It is possible to replace the used parts with their analogues. In particular, instead of the transistors indicated on the circuit diagram, others from the MP39-MP42A series, as well as (all at once) MP35-MP38A will be suitable structures p-p-p. But in the latter option, you will have to reverse the polarity of connecting the power supply and oxide capacitors.

Transformer T1 - output, from radio receivers of the "Selga-404" type. Dynamic head - 0.1 GD-8 or another, having a voice coil resistance of 8-10 Ohms.

(on MP transistors)

Models of bygone steam locomotives are undoubtedly impressive. This impression can be strengthened by building the proposed simulator of the sounds that accompanied the periodic release of steam from a real locomotive. People of the older generation remember that when the locomotive was parked, excess steam was released by a special valve with a frequency close to 1 Hz, and as the locomotive began to move and gained speed, the frequency of steam release increased.

Electrical diagram A simulator of such sounds is shown in Fig. 1. It includes an infra-low frequency generator, a white noise source, an AF signal amplifier and a sound emitter. The generator is made using transistors VT1, VT2 according to an asymmetrical multivibrator circuit. The frequency of the pulses it generates is determined by the resistance of resistors R1, R2 and the capacitance of capacitor C1. Using a variable resistor R1, you can change the time constant of the chain of these parts, and therefore achieve the best sound effect.

From resistor R3, the generator signal goes to the cascade, in which transistor VT3 operates with the collector turned off. As a result, the signal passing through the cascade is “colored” with a characteristic hiss. The generated signal is fed further through capacitor C2 and an AF amplifier assembled on transistors VT4 - VT6. Transistor operating mode DC stabilized by introducing negative feedback from the emitter of the amplifier's output transistor to the base of the input transistor. The amplifier is loaded onto the dynamic head BA1, which acts as a sound emitter.

In place of transistors, p-n-p structures can be MP39 - MP42 with any letter index or MP25, and in place of transistors n-p-n structures- MP35 - MP38 also with any index. For the role of the “noise” transistor VT3, you should try several copies from among those available and choose the most “noisy” one (this can be done, of course, only after checking and adjusting the simulator.

Fixed resistors - MLT with a power of up to 0.5 W, variable resistors K1 - SP-0.4, SPO-0.15. Capacitor C2 - two parallel-connected CLS or MBM with a capacity of 0.1 μF, the rest are oxide K53-1, K50-6. Dynamic head 0.25GDSh-2 or other small-sized with a power of up to 0.5 W and a voice coil with a resistance of 30...50 Ohms. The power source can be two 3336 batteries connected in series or six galvanic cells - it all depends on the requirements for the dimensions of the device and the expected intensity of its use.

The simulator parts are mounted on a board (Fig. 2) made of one-sided foil material. The connecting conductors on the board are formed as a result of cutting grooves in the foil. The board with the power supply can be placed in a case of suitable dimensions or inside a power supply unit, if it is used in working together with a simulator.

After assembling the board and checking the installation, supply power with switch S1 and check the current in the dynamic head circuit. If necessary, it is installed within the limits indicated in the diagram by selecting resistor R7. Then they select the most “noisy” transistor VT3, after which they move the variable resistor motor from one extreme position to another several times and check the limits for changing the frequency of “blowing off steam”. If they are insufficient, select parts R1, R2, C1.

In the case of using a simulator with an electrified model railway, in which the speed of the locomotive is controlled by a rheostat handle, it is advisable to mechanically connect the rheostat slider to the slider of the variable resistor R1, which will allow for a more natural sound simulation.

Radio No. 7, 1995 p. 29-30.

Unusual sounds and sound effects obtained using simple radio-electronic attachments on CMOS chips can capture the imagination of readers.

The circuit of one of these set-top boxes, shown in Figure 1, was born in the process of various experiments with the popular K176LA7 (DD1) CMOS chip.

Rice. 1. Electrical diagram of "strange" sound effects.

This circuit implements a whole cascade of sound effects, especially from the animal world. Depending on the position of the variable resistor motor installed at the input of the circuit, you can get sounds that are almost real to the ear: “croaking of a frog”, “nightingale’s trill”, “meowing of a cat”, “mooing of a bull” and many, many others. Even various human inarticulate combinations of sounds like drunken exclamations and others.

As is known, the nominal supply voltage of such a microcircuit is 9 V. However, in practice, to achieve special results, it is possible to deliberately lower the voltage to 4.5-5 V. In this case, the circuit remains operational. Instead of the 176-series microcircuit in this version, it is quite appropriate to use its more widespread analogue of the K561 series (K564, K1564).

Oscillations to the sound emitter BA1 are supplied from the output of the intermediate logical element of the circuit.

Let's consider the operation of the device in the "wrong" power supply mode - at a voltage of 5 V. As a power source, you can use batteries from cells (for example, three AAA cells connected in series) or a stabilized mains power supply with an oxide capacitor filter installed at the output with a capacity of 500 µF with an operating voltage of at least 12 V.

A pulse generator is assembled on elements DD1.1 and DD1.2, triggered by a “high voltage level” at pin 1 of DD1.1. The pulse frequency of the audio frequency generator (AF), when using the specified RC elements, at the output of DD1.2 will be 2-2.5 kHz. The output signal of the first generator controls the frequency of the second (assembled on elements DD1.3 and DD1.4). However, if you “remove” the pulses from pin 11 of element DD1.4, there will be no effect. One of the terminal element inputs is controlled through resistor R5. Both generators work in close conjunction with each other, self-exciting and implementing a dependence on the input voltage in unpredictable bursts of pulses at the output.

From the output of element DD1.3, pulses are supplied to a simple current amplifier on transistor VT1 and, amplified many times, are reproduced by piezo emitter BA1.

About details

Any low-power silicon device will be suitable as VT1 pnp transistor conductivity, including KT361 with any letter index. Instead of the BA1 emitter, you can use a TESLA telephone capsule or a domestic DEMSH-4M capsule with a winding resistance of 180-250 Ohms. If it is necessary to increase the sound volume, it is necessary to supplement the basic circuit with a power amplifier and use a dynamic head with a winding resistance of 8-50 Ohms.

I advise you to use all values of resistors and capacitors indicated in the diagram with deviations of no more than 20% for the first elements (resistors) and 5-10% for the second (capacitors). Resistors are MLT type 0.25 or 0.125, capacitors are MBM, KM type and others, with a slight tolerance for the influence of ambient temperature on their capacitance.

Resistor R1 with a nominal value of MOhm 1 - variable, s linear characteristic resistance changes.

If you need to focus on any one effect you like, for example, “the cackling of geese,” you should achieve this effect by rotating the engine very slowly, then turn off the power, remove the variable resistor from the circuit and, after measuring its resistance, install it in the circuit constant resistor the same denomination.

With proper installation and serviceable parts, the device begins to work (make sounds) immediately.

In this embodiment, sound effects (frequency and interaction of generators) depend on the supply voltage. When the supply voltage increases by more than 5 V, to ensure the safety of the input of the first element DD1.1, it is necessary to connect a limiting resistor with a resistance of 50 - 80 kOhm into the conductor gap between the upper contact R1 in the diagram and the positive pole of the power source.

The device in my house is used for playing with pets and training the dog.

Figure 2 shows a diagram of a variable audio frequency (AF) oscillation generator.

Fig.2. Electrical circuit of an audio frequency generator

The AF generator is implemented on the logical elements of the K561LA7 microcircuit. A low-frequency generator is assembled on the first two elements. It controls the oscillation frequency of the high-frequency generator on elements DD1.3 and DD1.4. This means that the circuit operates at two frequencies alternately. To the ear, mixed vibrations are perceived as a “trill”.

The sound emitter is a piezoelectric capsule ZP-x (ZP-2, ZP-Z, ZP-18 or similar) or a high-resistance telephone capsule with a winding resistance of more than 1600 Ohms.

Performance property of the K561 series CMOS chip wide range supply voltages used in sound scheme in Figure 3.

Fig.3. Electrical circuit of a self-oscillating generator.

Self-oscillating generator on the K561J1A7 microcircuit (logic elements DD1.1 and DD1.2-fig.). Receives supply voltage from a control circuit (Fig. 36), consisting of an RC charging circuit and a source follower on field effect transistor VT1.

When the SB1 button is pressed, the capacitor in the transistor's gate circuit is quickly charged and then slowly discharged. The source follower has a very high resistance and has almost no effect on the operation of the charging circuit. At the output of VT1, the input voltage is “repeated” - and the current is sufficient to power the elements of the microcircuit.

At the output of the generator (the connection point with the sound emitter), oscillations with decreasing amplitude are formed until the supply voltage becomes less than permissible (+3 V for K561 series microcircuits). After this, the vibrations stop. The oscillation frequency is selected to be approximately 800 Hz. It depends and can be adjusted by capacitor C1. When the AF output signal is applied to a sound emitter or amplifier, you can hear the sounds of a “cat meowing”.

The circuit presented in Figure 4 allows you to reproduce the sounds made by a cuckoo.

Rice. 4. Electrical circuit of a device with imitation of a “cuckoo”.

When you press the S1 button, capacitors C1 and C2 are quickly charged (C1 through diode VD1) to the supply voltage. The discharge time constant for C1 is about 1 s, for C2 - 2 s. The discharge voltage C1 on two inverters of the DD1 chip is converted into a rectangular pulse with a duration of about 1 s, which, through resistor R4, modulates the frequency of the generator on the DD2 chip and one inverter of the DD1 chip. During the pulse duration, the generator frequency will be 400-500 Hz, in its absence - approximately 300 Hz.

Unusual sounds and sound effects obtained using simple radio-electronic attachments on CMOS chips can capture the imagination of readers.

The circuit of one of these set-top boxes, shown in Figure 1, was born in the process of various experiments with the popular K176LA7 (DD1) CMOS chip.

Rice. 1. Electrical diagram of "strange" sound effects.

Oscillations to the sound emitter BA1 are supplied from the output of the intermediate logical element of the circuit.

A pulse generator is assembled on elements DD1.1 and DD1.2, triggered by " high level voltage" at pin 1 of DD1.1. The pulse frequency of the audio frequency generator (AF), when using the specified RC elements, at the output of DD1.2 will be 2-2.5 kHz. The output signal of the first generator controls the frequency of the second (assembled on the elements of DD1 .3 and DD1.4). However, if you “remove” the pulses from pin 11 of element DD1.4, there will be no effect. One of the inputs of the terminal element is controlled through resistor R5. Both generators work in close conjunction with each other, self-exciting. realizing the dependence on the voltage at the input into unpredictable bursts of pulses at the output.

From the output of element DD1.3, pulses are supplied to a simple current amplifier on transistor VT1 and, amplified many times, are reproduced by piezo emitter BA1.

About details

Any low-power silicon pnp transistor, including KT361 with any letter index, is suitable as VT1. Instead of the BA1 emitter, you can use a TESLA telephone capsule or a domestic DEMSH-4M capsule with a winding resistance of 180-250 Ohms. If it is necessary to increase the sound volume, it is necessary to supplement the basic circuit with a power amplifier and use a dynamic head with a winding resistance of 8-50 Ohms.

Resistor R1 with a nominal value of 1 MOhm is variable, with a linear characteristic of resistance change.

If you need to focus on any one effect you like, for example, “the cackling of geese,” you should achieve this effect by rotating the engine very slowly, then turn off the power, remove the variable resistor from the circuit and, having measured its resistance, install a constant resistor of the same value in the circuit.

With proper installation and serviceable parts, the device begins to work (make sounds) immediately.

The device in my house is used for playing with pets and training the dog.

Figure 2 shows a diagram of a variable audio frequency (AF) oscillation generator.

Fig.2. Electrical circuit of an audio frequency generator

The sound emitter is a piezoelectric capsule ZP-x (ZP-2, ZP-Z, ZP-18 or similar) or a high-resistance telephone capsule with a winding resistance of more than 1600 Ohms.

The ability of the K561 series CMOS chip to operate over a wide range of supply voltages is used in the audio circuit in Figure 3.

Fig.3. Electrical circuit of a self-oscillating generator.

Self-oscillating generator on the K561J1A7 microcircuit (logic elements DD1.1 and DD1.2-fig.). It receives the supply voltage from the control circuit (Fig. 36), consisting of an RC charging chain and a source follower on the field-effect transistor VT1.

The circuit presented in Figure 4 allows you to reproduce the sounds made by a cuckoo.

Rice. 4. Electrical circuit of a device with imitation of a “cuckoo”.

The discharge voltage C2 is supplied to the input of the AND element (DD2) and allows the generator to operate for approximately 2 s. As a result, a two-frequency pulse is obtained at the output of the circuit.

The schemes find application in household devices to attract attention with a non-standard sound indication to ongoing electronic processes.