Scaring birds away from the garden, summer cottage, household plots, industrial and other buildings is not an easy task. For these purposes, I came up with and assembled a simple device – a bioacoustic repeller (repeller), which will effectively save inveterate summer residents and gardeners from feathered adversity. Also, this applies to farmers and agricultural landowners for whom birds do more harm than good.
First, I suggest watching a video on my YouTube channel:
Visual symbols of birds of prey have long been actively used at airports.
devices for certain types of birds.
Earlier, I rejoiced at the pandemonium of different species of birds during the spring digging of my summer cottage. Thinking about how many pests – caterpillars and various other insects – are destroyed by birds at this time of the year.
But, after a cherry tree appeared on my site, my attitude towards the winged “angels” changed radically. Over the course of several years, these winged creatures have feasted on the fruits of my back-breaking labor, both literally and figuratively. Every spring I watched my early, May cherry, as it is deliberately destroyed by flocks of starlings.
In addition to the crows, one fine morning an incredibly beautiful bird flew in to feast on the fruits of ripe cherries – in yellow-green plumage. As a result, with each passing day, cherries became less and less. My family and I had to be content with unripe or pecked fruit, in the form of tasting.
Thus, measures had to be taken to preserve the harvest. The first experience was an attempt to escape from flying “squadrons” with the help of sparkling CDs and foil. A classic scarecrow made of some kind of overalls, which was located in a neighboring area, scared me more by its appearance than exterminators of fruit and vegetable crops.
Of course, such a pest control method did not bring any practical effect. The next year, tactics had to be changed. In addition to the fact that I started eating unripe cherries – green-red in color, I also tried other methods of protection from birds. I read somewhere that fruit trees can be protected from birds with a net. That is, covering a garden, or a separate fruit tree with a plastic net, you can save most of the harvest. I really liked this idea, and given the small size of my tree, I used a more affordable material.
For these purposes, potato bags made of plastic mesh are perfect. Used bags, even torn ones, are fine. First, you need to cut the bottom, and after that the bag is put on a branch of a fruit tree. Also, one end is tied using an existing twine, and the other end of the bag is attached to the base of the branch, using a soft wire or rope. This measure of protection takes some time, but the effect was obvious: the starlings could not reach the cherry fruit with their beaks. Partially they managed to peck at the surface of the fence. And for several years this measure has been the most effective. But this year I am tired of tying and untie these notorious mesh bags.
To implement this project, you will need the following materials and tools:
– case for the device: plastic container ( or any other suitable size);
– photo sensor body: plastic capsule from “Kinder Surprise” (or any other transparent/translucent body);
– one and a half liter PET bottle;
– scotch tape;
– VT1 – 2N3906 (bipolar PNP); (BD234, BC307, KT3107);
– VT2 – AOD436 (MOSFET NPN); (IRFZ44N, IRF630/640);
– VD1 – LED red (640nm) L-53SRD-E;
– PH – SK-KE-10720 (Light Dependent Resistor 650nm 5MM);
– R1 – 1k Variable resistor;
– R2 – 10;
– R3 – 10k;
– R4 – 680 (1-1.5k);
– MP3 Player (FQ # 59 Digital speaker);
– Li-Ion battery 18650, 3.7V, 2000 – 40000 mAh.
– charging/power supply 5V, current from 1A and above;
– solar battery 5-18V current from 250mA and above;
– speaker in the form of a horn;
– dc-dc voltage converter;
– charging board for lithium-ion batteries with protection;
– electrical wires and connectors;
– plastic ties;
– and other consumables (heat shrink, adhesive tape, etc.).
– soldering iron and consumables for him;
– glue gun;
– assembly knife;
– nippers, screwdriver, and other tools.
Device connection diagram Electronic circuit of the device In the circuit I have developed, the light sensor is a photoresistor PH, which, together with the trimming resistor R1, forms a voltage divider, which allows you to change the level of the controlled voltage to the base of the transistor VT1. As soon as the light level rises, lowering the resistance of the photoresistor gives enough voltage to turn on the pnp transistor. This type of transistor is used for a reason, it opens with a negative voltage. If you use a transistor with an npn junction structure, then the circuit will work the other way around. That is, the transistor will open at dusk, for the device to operate at night. This circuitry can be used if you need to turn on, for example, an LED lamp: turn it on when the level of natural light decreases.
Further, the opening of the transistor VT1 causes a change in the gate operation threshold VT2. By using a field-effect MOSFET to connect the load, the effect of hysteresis is reduced. The properties of a field-effect transistor are to open with a small electric field, which is ideal for its operation as a switch transistor. In the binding of this key, I set the standard protective resistance R2 at 10 ohms, as well as resistance R3 at 10 kΩ.
The voltage divider created on the resistors R2 and R3 can adjust the control voltage between the drain and the source to turn on the field-effect transistor VT2. To indicate the operation of the photo sensor, between the emitter and the minus of the power supply, you can install the VD1 LED, with a limiting resistor R4. Thus, when the transistor VT1 opens, a current flows between the emitter and the collector, which feeds this chain. If you do not need this light indication, then it can be excluded. The load in this circuit is connected to an MP3 player.
When a field-effect transistor is triggered a current flows between the drain and the source, which feeds the load. The MP3 player is powered by a single lithium battery. The voltage in the region of 4 Volts is quite enough for the operation of this circuit, and it also simplifies the design as a whole.
I would also like to say about the use of a field-effect transistor in this circuit as a key. I used a small size TO 252 transistor that I found in old motherboards from computers. Usually, low-voltage (with a switching threshold of about 4 volts) radio-electronic components are used there. If you use other field-effect transistors, then you need to take into account the voltage of their work.
MOSFETs (metal-oxide-semiconductor field-effect transistors) have great advantages in such circuits:
They use minimal control power and have high current gain. Also resistant to large voltage pulses. In key mode, they have a high switching speed. Thus, in this circuit, the use of a field-effect mosfet transistor simplified the circuitry of its connection and lowered the level of hysteresis during its operation. Initially, I set the task of creating as simple a photo relay circuit as possible for controlling bioacoustic bird scaring.
The minimum set of parts in this circuit makes it simpler and more reliable, and also allows you to solder all the components with a simple hinged installation. These radio parts can be found in old boards from computers and other electronics. And the MP3 player can be replaced with another information carrier, say an old phone, by adding a small standard amplifier that can be connected to the speaker output of this phone.
In the photos you can see the process of assembling the bioacoustic repeller. Assembling and installing components is easy to repeat.
Setting up the device converges to adjusting the line-by-line resistor R1 in the photo relay circuit. It is necessary to find such a position of the line-by-line resistor so that the photo relay turns on at dawn and turns off at sunset (at about 8-9 pm).
I set the interlinear in the region of 2 kOhm. In this device, the recording is played from morning to evening, that is, during the daytime.
The audio recording is played back at intervals of about 10 minutes for 1 hour after that everything starts over. At night, the device does not work and thus does not disturb the neighbors. The device is powered by solar energy. A small solar panel paired with two batteries does the job. In case of cloudy weather, the battery will have to be additionally charged from the mobile phone charger.
In an open field, care must be taken to install the speaker at a height of about 2 m or higher. Also take care of the tightness of the device case. The speaker or horn must be installed so that no water gets into it and condensation does not accumulate.
The device is being tested confirmed my hopes, and proved to be effective against birds. Within about one week, I got rid of annoying starlings that ate cherries. After this “biotherapy” the birds avoided my site and no longer nest on my farm.
I think that the radius of my device is about 0.3 – 0.5 hectares (the exact parameters of the horn are not recorded on it). Well, if you need to save a large area for example – a few hectares of planting watermelons, then an additional amplifier must be added to this installation and, accordingly, a larger speaker.
To speaker sounded louder, to which I added a kind of horn made from a plastic bottle.
In order for it to fit snugly to the base of the speaker, you need to warm it up a little over a fire or use a building hair dryer.
All this is fixed to the base with adhesive tape.
On the back side, it is also desirable to isolate the speaker from the effects of weather conditions.
In the manufacture of this circuit, I was pushed by the fact that once, a long time ago, a future schoolboy, I assembled a simple photo relay to turn on the lighting in the chicken coop. Reading old magazines such as Science and Life, Young Technician, Modelist Constructor, Radio and other similar publications, I tried to find some innovative applications for my knowledge. Thus, I assembled a primitive photo relay on a huge photoresistor FD2, and an even more huge old relay. My grandmother, in the village, liked this idea of lighting the chicken coop very much, because the chickens began to lay more often. The only thing that annoyed her was the bounce of the relay. At dusk, for some time the relay made an unbearable sound of switching the winding contacts. Therefore, I am a future member of the radio circle, I assembled another circuit consisting of a KP302 field-effect transistor and a thyristor-based load control. The scheme was not simple, found in some magazine. After etching the board and collecting all the components, I suffered for a very long time with its adjustment. I no longer remember what happened to the egg production of chickens, but fluorescent lamps hung in the chicken coop of my grandparents for a long time. Most likely, they already served as lighting for cleaning the chicken coop, and not for the performance of birds. Here's a story. Now times have changed, but the “birds” have remained the same!
PS If you need an audio recording to scare away birds – write to me on the mail or on the Youtube channel.
I wish you creativity and useful homemade products. Best regards, FLOMASTER. I will sell this homemade product or make it to order. Email me or leave comment for discussion details.