Dog Repeller: review of schemes for making their own hands

Dog Repeller: review of schemes for making their own hands

Repeller dogs, affectionate and good friends of man, is not necessary, but make animal repeller aggressive and evil - a sacred thing. Well still find a working scheme, is not it?

Let us consider some schemes for those who work with their hands.

Driving dogs repeller on modern element base



In the scheme (enlarged diagram here) as a generator uses a standard 555 timer on the chip IC1, operating at a frequency of 40 kHz (annoying frequency for dogs and cats).

To increase the signal power used by power transistors TR1-TR4. A second similar 555 timer IC2 forms antipodal signal. The circuit is optimized for high power output at ultrasonic frequencies. As the ultrasonic transducer oscillator is used. You can use a dual 556 timer.

The effectiveness of the scheme was tested by reducing the oscillator frequency to an audible level and replacement ultrasound transducer speaker. The device is powered from an external source and current consumption 4 A signal strength reached 110 dB!

The circuit consumes a relatively large current. Therefore, for manual execution of the power switch to perform better as a button for a short turn. When using the device in a stationary mode, in order to prevent, for example, unwanted damage garden or flower bed is better to use lead-acid batteries, it is desirable to control the device by any motion sensors.(D. Stringwell, Scunthorpe, North Lines, «Everyday Practical Electronics», December 2003)

Overview of Russian schemes Dog Repeller

The scheme from the magazine "РадиоКонструктор» №4 / 1999

Circuit solutions shown. There are two work-flop - infrasound on the D1.1 and D1.2 cells, generating pulses of a frequency of 2 Hz, and ultrasonic to D1.3 and D1.4, generating pulses of varying frequency from 20 kHz to 60 kHz.


Analogs to use Russian transistors, diodes and chips:

  • КТ315 - BFP719, 2SC633, BFP721, BFP722
  • КТ814, КТ815 - BD139, BD140
  • КД102А - 1N4004, 1N4007, 1A7, 0112, 0102
  • К561ЛА7 - CD4011A

Works scheme so. Flicker on D1.1 D1.2 generates pulses. Once installed on the D1.1 output unit, is allowed to work on the multivibrator D1.3 and D1.4 (unit arrives at their conclusions 8 and 12). Flicker begins to produce certain frequency (about 20 kHz). At the same time it begins to increase the voltage on C2 (charge through R2) and opens VT5 transistor including frequency control resistor R5 parallel additional resistance R4 + RK3. As a result, the total resistance is reduced and the frequency of the pulses at the outputs of the multivibrator D1.3 D1.4 quickly increased to 60 kHz. When the output D1.1 reappears low, ultrasonic flip-flop temporarily (for the duration of the negative half cycle of the output D1.1) is turned off. Thus obtained parcels pulse with a period of 0.5 seconds, imitating the barking of a much larger dog.

This is followed by a push-pull output stage transistors VT1-VT4 with the tweeter output.

The details - the chip can be K176LA7 Russian or equivalent CD4011, high-frequency head any sufficiently powerful and miniature.

Reviews of contradictory pattern: someone runs directly without setup, someone not.

The scheme described in the forum of the city Solntsevo site (

The scheme this repeller dogs collected by only one digital chip (DD1) and five transistors (VT1-VT5). On DD1.1 logical elements. and DD1.2, resistors R1, R2 and capacitors C1, C2 formed infrasound generator (multivibrator is symmetrical, forming rectangular pulses a frequency of about 1.5 Hz).


Analogs to use Russian transistors, diodes and chips:

  • КД521А - 1N4148, 1N3063, 1N3065, 1N3604
  • КТ315Г - BFP722, 2SC380, 2SC634
  • КТ3102А - BC546, BC547,
  • КТ3107А - BC556, BC557, 2SA733

Second multivibrator symmetrical elements built on DD1.3, DD1.4, Resistors R6, R7, capacitors C5, C6 and represents the ultrasonic generator of rectangular pulses whose frequency is 20 kHz and periodically (every 0.66 s) is increased by approximately 4 times. Relatively smooth periodic "withdrawal" of ultrasonic frequency up performs assembly comprising resistors R3-R5, NW capacitor, transistor VT1 and diodes VD1, VD2.

Formed on the output terminals 10 and 11 DD1 chip ultrasonic vibrations of rectangular shape have a small capacity. Therefore, they are amplified by the power push-pull bridge amplifier collected on transistors VT2-VT5. Emitter load of the amplifier is a piezoelectric transducer BF1, ultrasonic vibrations, infrasound modulated, are excited by it after clicking on the SB1 button functions as a conventional power switch. DD1 chip power supply circuit is protected from accidental "polarity" battery GB1 diode VD3, and filter capacitors C4 and C7 provide a passing through the chain of supply, respectively, high and low frequency vibrations.

GB1 battery can be composed of six to ten battery cells (316), batteries, or use ready-made 12-volt battery L1028. K561LA7 (CD4011A) chip can replace K176LA7 (CD4011). Diodes VD1-VD3 - any silicon compact, VT1 transistor - any low-power silicon with a current gain of the base of not less than 30. The transistors VT2. VT4 and VT3, VT5 replaceable by any of the series respectively KT3102 and KT3107.
When configuring to repeller dogs which mainly consists in the selection of the resistor R3, it was possible to monitor it on the ear at the time of parallel capacitors C5 and C6 connected by soldering two capacitor least 6800pF each.

Corps to build the repeller was the case from the failed FM radio stations of the Chinese manufacture.

About piezo BF1 SQ-340L. It is possible to recommend to use instead opovestiteli ultrasonic MFC-200 having a high sound pressure to 85 dB, and therefore long range.

Review: "Gathered in this one scheme alone, but she did not want to work. When the ultrasound gives a short signal at 0.5 ... 1 seconds and stops."

The scheme a powerful repeller dogs (as posted in the forum of the city Solntsevo site (


Analogs to use Russian transistors, diodes and chips:

  • КП501А - ZVN2120
  • К561ТЛ1 - CD4093A
  • КД522А - 1N4148

In this scheme, the first logic element assembled generator modulating frequency, which prolongs the life of the battery and increases the effectiveness of scaring dogs. The frequency of the generator should be located in the vicinity of 14 Hz.

The second logic element assembled ultrasonic signal generator frequency of 24-25 kHz, which is controlled by the first generator. Thus obtained pulse train with a frequency of 24-25 kHz.

Subsequent logic elements are buffered and partitioned into 2 output signal cascade. ZVN2120

The output stages are implemented with transistors КП501A (ZVN2120) with a valid reverse voltage - 100 V. The load they are DR (3.3 or 4.7 mg) - MH and consistently included diodes with reverse voltage of 200 V and a frequency of at least 100 kHz. These diodes eliminate parasitic oscillations that occur in chokes and summarize them to the amplitude of the pulse. Thus, they are added to the 10 V high voltage pulse amplitude obtained.

The piezoceramic transducers TR2516T1 resonance and are designed to operate in the frequency range of 24-26 kHz. Their own capacity of 2000 pF. There may only be replaced with others with similar parameters.

LED connected via a zener with a voltage of 5.1 V and a series resistor, it is the low battery indicator. When the LED is dimly lit or completely extinguished - it is necessary to change the battery. The second LED - device power indicator. Used burning bright LEDs.

Field effect transistors may be others - most importantly, the maximum reverse voltage is not less than - 100 V (preferably 150-200 C). The fact is that when a random emitters disconnecting the drain voltage is increased to 100 V.
Note. Do not burn the input of the oscilloscope, taking into account such stress on the radiators.

Device configuration

Check whether the voltage pulse to the emitter - it should be of the order of - 60 V and a frequency (24-25 kHz).

Instead of a resistor (12K, which is marked with an asterisk) are temporarily soldered trimmer nominal value of 15-20K and rotate it in a small range, while controlling impulses to the radiators. Upon reaching transducer resonance becomes maximum amplitude pulse and it becomes as depicted in the diagram. Its top should be slightly flat. Then measure the resulting resistor value and a fixed resistor soldered. Check pulses to the device then 2 channels.

Circuit current consumption - no more than 20 mA and depends on the correct setting.

Indicator LED - yarkogoryaschy. If other LEDs is necessary to choose the dropping resistor (10 K) in the direction of decreasing the nominal value.

Adjust frequency ultrasound is necessary because the emitters resonances are spread in frequency. If possible, the radiators also have to pick up on the maximum amplitude of the pulse on them.

Reviews of fitness to work there.

The scheme Dog Repeller by Cosmonaut (форум

The following is quoted author's text.

Collected here are a deterrent. Effective on dogs in different ways, from 90% stray escape, a trained anyway. The sound is loud, very unpleasant as dB do not know, there is nothing to measure, but it lays the ears well. As the radiator applied the horn of a car alarm, but can equally well using conventional speaker 4 ohms, of course, more powerful speaker, the louder the sound, but within the capability of the amplifier. The circuit consumes a large current, so you need a good battery with a voltage of 6 to 12V (with a "crown" will have no effect).

The advantage of this scheme is that it can help to customize virtually any speaker on its resonant frequency, and get in the end a very loud sound. In this case, with this horn frequency it is within 2.5-2.7 kHz. Moreover, the sound is very pure, since the output sinusoidal signal is obtained. Serve meander from an external source, the effect is not worse, but will still be present and "buzz". Even this may be better not to use pugalka dogs and rodents living storages in conjunction with a motion sensor. Such a sharp sound they are unlikely to enjoy, and at the same time no one will bother. Here the scheme itself, the inclusion of this model K174UN7 chip (ТBА810AS, LA4420), with the difference that the output of the amplifier is connected to the input of the capacitor and the desired frequency is adjusted by the variable resistor. Such ready ULF on a separate circuit board can be removed from the old TV, and you can use any other similar power.


Analogs to use Russian transistors, diodes and chips:

К174УН7 - A210K, ТBА810AS, LA4420, A205K,D, A210K,DUL1481PT, ULA6481