An electric shepherd or electric fence is a kind of device that is used for various purposes. It helps protect animals or protect against animals. The design of the ignition coil device is quite simple, so you can create it yourself. Strictly speaking, an electric shepherd is a generator that transmits current through a wire. Voltage helps scare away large animals, protect crops, or protect livestock from attacks by wild animals.
Why do you need an electric shepherd and how does it work?
- Metal wire, which makes up the main part of the fence.
- Generator, it transmits current through the wire.
The device of the electric shepherd is simple. The live wire does not allow the animal to leave the pen or go beyond its boundaries. If cattle are grazing in a certain place, the electric shepherd will not allow them to leave the pasture area. But you can see what a factory device for cows looks like.
Circuit and software component of the electric shepherd.
If cows graze freely, which is suitable for, then the fence will help protect crops, haystacks, flowers and other decorative plants from them.
On the video - why an electric shepherd is needed:
On some farms, such a fence is used to protect the feeders of other animals from pigs.
Electric shepherds are also used to protect their own plot of land from “encroachments and raids” by various animals. The fence is installed around the perimeter.
What is needed to create a device from an ignition coil with your own hands - diagram
- metal wire or mesh a (it should not touch the ground);
- pillars, capable of withstanding high voltage;
- grounded source high voltage pulses.
Do not be afraid that the current will harm a person or animal. The impulses will not cause harm and are not life-threatening. Contact with a fence is fraught with the occurrence of inconspicuous sensations and severe discomfort, which will scare away the animal, but will not cause significant harm to its health. Provided that all safety rules are followed. It may also be useful for you to know what this problem looks like and what can be done about it.
On the video - how to make equipment with your own hands:
Cons and pros
Among the advantages of a fence it is worth highlighting:
- Reliable protection from cattle raids and more.
- Relative ease of creation.
- Relatively low cost.
If you construct a fence yourself, problems may arise:
- with source material;
- with the diagram and its understanding.
It is advisable to have certain design skills; this will help to avoid mistakes when creating an electric shepherd. But what the symptoms of mastitis in cows may be will help you understand.
The principle of creating a homemade electrical device for shepherds for livestock
You will need an ignition coil. It will act as a voltage source and as a device that converts voltage into impulse. In order for the fence to only scare away livestock and not kill them, it is necessary to focus on the transmission of short impulses.
They will be repeated at a certain frequency (interval). It is not difficult to make a generator if you take a completely finished transistor, which will transmit impulses or directly to the ignition coil from a passenger car. But what breeds of dairy cows there are and how to raise them correctly are indicated.
The ignition coil plays the role of a transformer; it is a device that performs 2 functions. The coil “generates” voltage and converts it into impulses.
High voltage pulses in the car are transmitted to the spark plugs, and in the electric shepherd they are sent to the fence. What to do with mesh or wire, as well as poles, is very clear. After the structure is installed, it should be connected to the generator. You may also be interested in learning about what it looks like and what conditions exist for its maintenance.
Creating and connecting a generator
- Step-by-step analysis of creating a generator:
- To obtain a voltage source, it is necessary to apply voltage to the “primary”; it consists of pulses formed in “packs” that are repeated with a certain periodicity.
- The pulses will be transmitted to 3 555 brand timers.
- If we take timers A1 and AZ as a basis, they can become a source of infrasound and sound vibrations.
- A one-shot monovibrator will be created based on timer A2.
- The voltage from the coil will flow to the “primary” T1 and go through the switch on the transistor.
- In order for the required voltage to appear on the “secondary” T1, it is necessary to ensure that the current pulsates on the “primary”, creating pulses.
- As a result, it is possible to obtain the formation of a pulsating voltage on the “primary” T1, it is induced on the “secondary”, which makes it possible to obtain an alternating voltage on the “secondary”.
- Through the level at output 4 AZ it will be possible to control the generator. But in order for the generator to operate fully at this level, it is necessary to ensure the presence of a logical unit voltage.
- Logical zero will allow you to block the device and set the same indicator at the output of the generator.
- The A1 base will allow you to make a sound generator that will generate sound pulses. You can regulate the pulse frequency and configure them using resistor K1.
- Voltage in the form of pulses will go to outputs 2 A2 from pin 3 A1.
- The frequency of pulse transmission to the fence will depend on this device.
If we take the A2 timer circuit as a basis, we can create a one-shot circuit. When voltage is applied to pin 2, it will form a certain pulse, the duration of which can be selected independently using resistor number K4. This signal is in the nature of a pulse and will be sent to resistor B10. It goes to the gate of the switching, field-effect and fairly powerful transistor UT1. In its stock circuit there will be a connection to the “primary” of a standard ignition coil from a T1 passenger car. You may also be interested in information about how to increase your milk yield.
It is worth noting that any ignition coil is suitable for creating a fence, but it is better to give preference to a car coil with a contact ignition system, such as the following cars:
- Moskvich 412;
- Moskvich 2140;
- Zhiguli 2106;
- Zhiguli 2101.
But you can find other suitable cars with a contact ignition coil, which is suitable for creating an electric shepherd. But you can read how much hay a cow needs for the winter and what feed is the most effective.
Consequences of using electric drives for sheep and cows
It is advisable to choose a scheme with a short pulse, because if the pulse is long and quite powerful, the animal will not be able to leave the dangerous place. The unpredictable behavior of the animal (this rule applies to horses to a greater extent) is caused by muscle spasm.
Different animal species require different characteristics. Therefore, before starting to manufacture an electric fence, you should familiarize yourself with the related information.
Disadvantages of such a generator:
- It works constantly, consumes a lot of energy, which leads to rapid wear of the battery.
To protect your plot of land from animals (and not only) you can use an electric fence, which is made of wire or metal mesh stretched on insulating posts; it does not come into contact with the ground, but is connected to a grounded source of high-voltage pulses. In relation to the life of animals or people, this does not pose a danger, but it gives a rather unpleasant and frightening feeling.
In order for the electric fence to perform only a repellent function, it is necessary to apply short high-voltage pulses to it, which are repeated at a certain interval.
You can make a pulse generator according to the circuit shown in Fig. 1. The generator is based on a ready-made high-voltage transformer; its role can be played by an ignition coil taken from a passenger car. The ignition coil is a transformer with a low-resistance primary and high-resistance secondary coils. When current ripples in the primary, high voltage pulses are formed on the secondary. In a car they go to the spark plugs, but here they go to the fence.
For the circuit to operate, a pulse voltage must be applied to the primary, which consists of intermittent trains of audio frequency pulses; they are repeated after a certain period of time. The circuit for recreating these pulses is made using three 555 integrated timers.
Generators of infrasound and sound vibrations, respectively, were manufactured based on timers A1 and AZ. Based on timer A2 - one-shot.
The current to the primary of the ignition coil T1 goes through the switch on the field-effect transistor LG 1. In order for a high voltage to form in the secondary T1, the current must pulsate in the primary. A sound pulse generator is made based on the AZ timer. When it works, audio frequency pulses from its output (pin 3) go to the gate of the transistor. As a result, a pulsating current is formed on the primary T1, which induces a high alternating voltage on the secondary.
The sound pulse generator is controlled by the level at pin 4 AZ. In order for the generator to operate at this pin, a logic one voltage is needed. At logical zero, the generator is blocked and its output is set to logical zero.
An infrasound generator is made based on the A1 timer; it generates pulses. The frequency of these pulses can be adjusted using variable resistor K1. The frequency of supplying high-voltage pulses to your fence depends on this generator. Pulses from pin 3 of A1 go to pin 2 of A2.
Printed circuit board
A one-shot circuit is made based on timer A2. Upon arrival of each pulse at pin 2, it forms one pulse of a given duration, which can be adjusted using variable resistor K4. This pulse signal goes through resistor B10 to the gate of the powerful key field-effect transistor UT1A, in its drain circuit the primary of the standard automobile ignition coil T1 is connected. Almost any ignition coil can be used. It is better to use a coil from cars with a “contact” ignition system. For example, from Zhiguli VAZ - 2101 or 2106, from Moskvich 412 or 2140.
The basis of the article is taken from the magazine "RADIO CONSTRUCTION"
"represents the following design: the pasture is fenced with bare wire suspended on insulators. A voltage of 1.5...5 kV is supplied to it from a pulse generator. Having touched the wire, the animal receives an unpleasant electric shock, which, of course, is safe for its life.
After several touches, the animal develops a conditioned reflex, and it no longer tries to go beyond the fence. The current can be up to 15 mA (sinusoidal current with a frequency of 50 Hz), with short pulses the pulse generator current can increase to 500 mA. From a safety point of view, the pulse duration should not exceed 0.1 s, and the interval between pulses should be at least 0.75 s. In factory-made electric fences, the pulse duration is several milliseconds with a repetition rate of about 1 Hz, a voltage of 5 kV and a current of up to 300 mA (electric charge of up to 3 mC). Animals are most affected by impulses with a frequency of 250 Hz.
In Fig. 1.1,a shows a circuit diagram "electronic fence" This high voltage generator, producing a voltage of 1.6...2 kV with a frequency of 1 kHz. The voltage pulse appears once per second and lasts about 100 ms. It depends on the capacitance value of the capacitor C1 and resistor resistances R1, R3. The main part of the device is the transformer Tr1. It uses a ferrite core from a TV's horizontal scan transformer. The primary winding has 55 turns of PEV 0.71 wire and the secondary winding has 18 turns of PEV-1 0.25 wire. The third high-voltage winding is taken ready-made from the line transformer. You can wind the high-voltage winding yourself, but it is difficult. It consists of 1600 turns of insulated wire with a diameter of 0.12 mm, wound in layers of 100 turns each with layers of capacitor paper. For the fence, use copper or galvanized steel wire with a diameter of 1- 1.5 mm. It is stretched between the posts, which are placed every 25 m.
Rice. 1.1. "electric shepherd"
a - basic electrical diagram (L1- 55 turns PEV 0.71; L2- 18 turns
PEV 0.26; L3- 1600 turns PEV 0.12; b -TV line transformer
converted to work in a generator.
Rice. 1.2. "Electronic fence":
o - wire fencing design; b - insulators for portable fencing.
Insulators - high-voltage insulators from power lines, or, in extreme cases, ordinary, porcelain. Insulators for portable fences can be made from plastic or glass bottles (Fig. 1.2, b) mounted on wooden stakes driven into the ground. Fence wire wraps around the neck of each bottle. It should not touch bushes, grass, etc. It is necessary to pay attention to good quality grounding. The ground is used as the second wire of the high voltage line. The distances between the fence wire and the ground for various cases are shown in Fig. 17.8, A.
Setting up the device consists of obtaining the maximum voltage at the output of the pulse generator. The magnitude of the voltage is judged by the length of the spark that is formed between the output terminal of the generator and the wire connected to the ground. Adjustment is made using variable resistors R1 and R2.
It is necessary to follow safety rules and under no circumstances touch exposed wires!
The operation of the device is checked by carefully bringing your hand to the wire; at a distance of 10 mm to the wire, a spark should jump with a dry crackle of a discharge, and a slight tingling sensation will be felt. Animals come under voltage at a distance of 2...4 mm. The fenced area is 5...10 hectares.
A few words about the benefits "electric shepherds" The fencing allows for the grazing of a larger number of animals than usual. This gives a 20...25% increase in milk or meat production. The fence protects farms and gardens from the invasion of uninvited four-legged guests.
They asked us to make an electric fence. I googled, there are a lot of diagrams, but nothing really caught my eye. Circuits powered by 220 volts are out of the question: stupid and dangerous. The common circuit on three 555 timers surprised with its redundancy; an electric chair based on the PWM ignition coil principle will not give a sufficient spark length and is just as dangerous.
What is an electric sheath? In the simplest case, it is a plot of land fenced with a wire or special tape under voltage.
So what happened:
The circuit operates from 10 to 14 volts. The primary converter charges C4+C5 to 400 volts, after which they are discharged to the ignition coil. The discharge frequency is regulated by R2 and limited by R3; these resistors are responsible for the duty cycle of the primary converter pulses. The converter itself is powered by the common SG3525 microcircuit, which in this connection requires a minimum of wiring. The frequency of the converter (C1 and R1) is selected depending on the transformer, in my case ~66kHz. In my case, the maximum duty cycle is limited by resistor R3 at ~18%, and the maximum current consumption from a 12-volt source is ~250mA. If the power is not limited, you may need a snubber and replacing the transistor with something more powerful, such as IRF3205.
C2 at 25 volts. Transformer T1 on the RM8 N87 AL=250 core is redundant, but no smaller cores were found. Calculate the turns in the Old Man program, in the secondary winding there are ~250 turns, this is enough with a margin on almost any core, and since This is a flyback, I highly recommend layer-by-layer insulation to avoid breakdown.
Next come two diodes and a current-limiting resistor R5, which uselessly consumes power, heats up and helps to lock the thyristor in this connection. It is better to make it a composite of two parallel or series resistors with a power of 2 watts of suitable ratings. Capacitors C4 and C5 at 630 volts. C3 can be taken at 50 volts. Ratings of the dinistor and thyristor in the diagram.
Resistor R6 regulates the response voltage of the threshold unit, I set it to 400 volts, which seems to me excessive, the spark is too powerful, all this will be adjusted during the experiments.
T2 – ignition coil, the primary winding is shunted by 3 serial HER208 diodes.
I don’t like the threshold node because of R5, it will be redone, but for experiments it will do just fine.
At the moment, the discharge frequency at maximum (R2) power is about 4Hz, it seems to me that more is not needed, but most likely less, if you leave this frequency and reduce the operating voltage of the threshold unit to 100-200 volts, the consumption will be about 50-100 milliamps, respectively, from a car battery this circuit will live forever.
For safety, it is planned to connect the HV output of the ignition coil to the fence through a 5 megaohm composite resistor, which will allow limiting the current that offends animals to a safe level.
Upd: The electric shepherd was tested, here is the video:
The voltage on the capacitors is reduced from 400 to about 150-200 volts, the spark is about two centimeters, maybe a little more.
Please enable JavaScript to view theIf the area allocated for pasture is large, then it can be difficult to fence it all off. And sometimes animals belonging to other owners also come to someone’s fields. In all cases, an electric shepherd comes to the rescue.
This device is a strip or wire that can be easily installed on a fence or moved to another location. The article will discuss how to make the device itself and a generator for an electric shepherd with your own hands.
How does the device affect animals?
When contacting such a fence, a current is passed through the animal’s body and goes into the ground. It is not life-threatening, but the horse, for example, will remember the unpleasant sensations it received here and will no longer approach such a place.
When the device is turned on, it generates and supplies voltage pulses emanating from the enclosing wire.
The generator for the electric shepherd organizes a walk that is safe and well controlled. You can simply forget about ropes, chains and similar devices, as well as all the hassle associated with them.
Kit in store
A generator for electric cattle shepherds can be purchased in the online store. It comes in foreign and domestic production. Typically the kit includes the following components:
- a unit that supplies voltage, powered by a battery or directly through the network;
- woven ribbon (it comes in different colors);
- pegs for insulators;
- the insulators themselves on which the tape is installed;
- wire for connecting the block and the grounded pin;
- the pin itself.
Instead of buying
Not everyone will want to pay personal money for this device. An alternative is the ability to make a generator for an electric shepherd yourself. As you can see from the kit, any radio amateur can assemble the device.
It is better to purchase the block in the store - it is sold separately. But if there is a circuit for a pulse generator for an electric shepherd, then that too can be made at home. Everything else can be easily assembled from what is on hand.
Useful tools at hand
A device made independently will be the most economical option.
Thin welding wire is used as an electric fence. And in order for the animals to see it, they stretch an additional ribbon with flaps. You can immediately provide a wide tape, but you will have to pay for it. True, in the wind it sags, and when wet snow falls, the latter settles and freezes on it, so the conductivity can be reduced.
But for the construction of insulators, you can come up with a lot of means, for example, a wooden stake with plastic bottles (as self-tapping screws), in which two vertical slits are made and a tape is threaded through them. Or you can simply wrap the post with tape. Instead of plastic bottles, some people use other things.
Grounding can be done using an ordinary piece of reinforcement or an iron rod, a little more than a meter in length. It is driven into the ground about a meter. For best performance, it is good to water the soil in dry weather.
To connect the block, conductor and fence, so-called crocodile cords for cars are used. They are cut in two.
If you buy columns, they will not be cheap. A lot of them are usually required, since the maximum distance from each other should be ten meters. But it is advisable to install them even more often. At companies, the posts are made of plastic. It is extremely difficult to find flattering reviews about such devices. They are praised only when the installation is temporary. But for long-term stationary installation, it is better to use wooden ones, made independently.
Of course, it will be more difficult to score them. It will hardly be convenient to hammer with a sledgehammer. And some people get out of this situation by first driving in metal corners and then screwing wooden posts to them. Alternatively, you can purchase a hand drill and use it instead of driving.
In general, if you use the device itself and the electric shepherd generator correctly, it will do its job perfectly. However, when the stallion is overly active, even such an electric fence will not be able to stop him. For such individuals, it is better to duplicate the fence. Although the matter will be troublesome and cost a pretty penny, the horse will be saved.
Some nuances
Make sure that the tape does not touch the ground, grass or snow. Otherwise, the battery will be constantly discharged on the ground.
The animal is accustomed to the device. After all, if panic sets in at the first collision, then the horse may rush in the other direction and break the wire there.
In addition, to avoid unnecessary troubles, you need to post signs for people warning about the presence of voltage.
Generator for electric shepherd
The diagram below can be used to assemble the device. A base from a ready-made transformer is used, namely from a car. This is a device with low-resistance primary and high-resistance secondary windings.
When pulsating, impulses arise. If in a car they act on candles, then in a processed form the current is supplied to the electric fence.
To operate the device, a pulse voltage (rhythmically repeating audio frequency pulses) is sent to the primary winding. The process is implemented on three 555 timer chips, where infrasound, sound vibrations and a monovibrator are collected.
The current for the electric shepherd is supplied to the primary winding via a switch. Voltage is generated on the secondary winding, and audio frequency pulses are output from the third timer to the gate of the transistor. Thus, a pulsating current appears in the primary winding of the pulse generator for the electric shepherd.
The device is controlled by sound pulses on the fourth pin A3. The launch occurs through the logical unit level.
The infrasonic generator is assembled on the first timer. The frequency can be adjusted by variable resistance R1.
From the third output of the first timer, the pulses go to the second output of the second timer, where the one-shot device is built. Each pulse arriving at the second output of the timer causes the generation of a corresponding pulse (the duration of which can be adjusted using resistance R4).
The pulses of the third output are transferred to the fourth through resistance R6. It turns out that the second timer sets the duration of the high-voltage pulses, which are transferred to the electric fence. In this case, the first timer sets their frequency.
Through the resistance, the pulse is sent to the gate of transistor VT1. The primary winding of the transformer is connected to the drain circuit, and alternating voltage pulses are generated on the secondary winding.
Conclusion
Thus, assembling the generator is the most difficult of all device manufacturing. However, with basic knowledge, a radio amateur can do this without difficulty.