Old Soviet and pre-revolutionary coins onthe market are quite expensive. You can also find them in the abandoned old villages and towns. However, the search for such small objects, in most cases already sprinkled with earth, without a special tool, would, of course, be extremely difficult. Therefore, modern treasure hunters use special detectors for this purpose.
Types of such devices on the current marketthere are many. And the simplest is "Butterfly". The metal detector (the photo of it is presented on the page) of such a construction is relatively inexpensive and at the same time quite convenient in operation. Therefore, consumer reviews, he deserved just excellent.
Design Features
This instrument got its name for having two coils resembling butterfly wings and located in the same plane. Such a metal detector works on the principle of disrupting the synchronization of frequency generators. The elements of its design are:
IC on operational amplifiers. Two of them receive coil signals. The third amplifier calculates the difference.
Speaker. The difference of signals is displayed on it.
The capacitor is variable. This element is designed to prevent capacitance distortion during adjustment.
Dielectric box under the scheme. It can be made of different materials.
Base for coils and rods. Its length can be 30-45 cm.
Rod made of dielectric material.
PEL wire 0.3-0.35 mm.
Batteries.
Two-core cable.
As you can see, the design of this metal detector is really simple. Including therefore he deserved quite good responses from consumers.
При желании сегодня можно приобрести metal detector "Butterfly" and with one coil. Such models work, of course, somewhat worse than usual. However, some coin seekers still consider them quite promising.
Operating principle
Distance between coils of the Butterfly toolis about 10 mm. As soon as any metal object, including underground, falls into the zone of action of one of them, the process of synchronization of generators breaks off. As a result, the sound signal penetrates the coin finder headphones.
Metal detector "Butterfly": reviews
Of course, most of the more complex and expensivemodels in terms of ease of use tools "Butterfly" inferior. However, using this detector you can find objects in the ground effectively. For example, the “Butterfly” “sees” a five-kopek coin of the times of the USSR at a distance of about 15 cm, covers from cans - 30 cm, hatches - 60 cm. Consumers have a good opinion about this device also because it can work under water.
The advantages of this metal detector, many includealso long work. One battery charge "Butterfly" is usually enough for as much as 20-30 hours. According to most searchers, it is also convenient to work with this device because it doesn’t weigh too much - only about 500 g.
Достоинств у этого прибора, таким образом, there are many. However, he has some drawbacks. For example, many coin seekers note the fact that ears often break in coils of the Butterfly device. In addition, such devices sometimes frayed the wires in the cable. In some cases, these metal detectors can malfunction and regular coils themselves.
Another indirect disadvantage of this devicethe opinion of many consumers, is that if it breaks down, finding a master for its repair can be difficult. For people who have no experience with electronics, this often becomes a problem. However, the device of this device is actually simple. And even if there is a minimum of skills with radio engineering, it will not be particularly difficult for a home craftsman to repair such a metal detector. Moreover, all sorts of parts for it are not too expensive and you can usually find them on sale easily. They are sold both in specialized and just in hardware stores.
Metal detector device and circuit
So, reviews of these devices are good, including because of their simple design. What kind of device does the Butterfly metal detector have? Let's deal with this in more detail.
In order for the tool to work effectively,the diameter of its coils should be not less than 21 cm. The coils of the wires on them should be 30. The withdrawal usually goes from the 10th. On the basis of the device fixed rod. The sensitivity adjustment system is also fixed here. Inside the boom, along with the headphone outputs, a cable is stretched. The power source for metal detectors of this type sometimes even serves as a simple battery from a mobile phone (in homemade models).
Кабель внутри штанги в таких металлоискателях extends along with headphone jack. This item is designed to turn on / off the device. Reviews of devices of this design are, therefore, quite good also because they begin to work immediately after the connector is inserted into the headphones.
Выше представлена схема простого металлоискателя "Butterfly" on two transistors. As you can see, it is not very complex. In any case, the scheme of this device is not critical in relation to the nominal details, the number of turns and power.
For what else deserves good reviews device
Искать монеты с помощью этого устройства на самом it's not too difficult. Consumers have a good opinion about the Butterfly devices also because they can automatically adjust to any soil. Also, the coin finder can determine the type of metal underground by the sound of the signal. In addition, due to the simplicity of the design of this device, it can be easily improved if desired. For this, of course, also feedback from consumers, he deserved just excellent.
In some cases, homeworkers are not evenacquire parts for the metal detector "Butterfly", and just take them from the old equipment. For example, for the coils of this device is suitable cable from the deviating system and demagnetization loop of the TV. The only thing in these devices are usually used headphones with high resistance. Unfortunately, it is quite difficult to find them. Ordinary audio headphones from old equipment cannot be used with this device. The sound on them in the search process will simply not be heard.
The main drawback of the device
Thus, the disadvantages of inexpensiveMetal detector "Butterfly", according to many consumers, almost none. In particular, it concerns the work efficiency and usability. This device finds coins at the same depth as the majority of quite expensive, including imported, models.
However, with regard to ease of use with thisdevices, one pretty serious flaw still exists. During operation of the Butterfly metal detector, there is often an inconvenience in adjusting the operating frequency of the generator. Finding the right rod position per millimeter fractions in a steppe or forest is, of course, quite difficult.
Nuances of manufacture
Do the metal detector "Butterfly" do it yourself,as mentioned, quite simple. The scheme of this device is not particularly complex. The only thing with its assembly should be to ensure that the left and right parts of it were the same. The device board is placed in a plastic box. Glue it to the frame-coil. The second board is usually supplemented with an amplifier with contact pads for three batteries and a headphone jack. Petals are cut from a tin can.
In the presence of an amplifier, the Butterfly metal detector can be used even with ordinary 30-60 ohm headphones. This, among other things, provides an economical mode of operation of the device.
К плюсам этого устройства многие потребители also include what is already mentioned, it can be easily improved. In addition to headphones, if desired, it will be easy to make the Butterfly metal detector with your own hands and be more convenient with respect to fine frequency tuning. To do this, on the board to which the petals are soldered, one should place a variable resistor with a resistance of 100 ... 150 Ohms. Then this board, like the first one, is placed in a box, and then the last one is attached on a rod near the handle.
How to make a metal detector "Butterfly" do it yourself: detailed instructions
This device is actually assembled as follows:
the bar is made, for example, from a plastic pipe of 26 mm.
to one of its ends is attached to the wheel of the bike;
the basis is made of plywood, polycarbonate, etc.
the assembled circuit is attached to the base together with the coils;
also on the basis of fixed rod and the node sensitivity adjustment;
wire is drawn inside the rod;
The battery from the mobile phone is glued to the base;
wires of power supply of generators and charging connector are soldered to its contacts;
the coil and the scheme are covered with furniture lacquer, and then - with silicone;
next to the coil, a trim knot is glued;
the armrest is made of a water pipe.
A plastic nut and screw with a piece of aluminum are used to adjust the metal detector during operation. The thread of this assembly is lubricated with grease.
Instead of concluding
So, judging by the reviews, the metal detector "Butterfly"can be considered a device in operation quite convenient. Using it, it is easy to find coins, both small and large, as well as any other metal objects in the ground. Of course, this cheap device also has its drawbacks. Some seekers even call it a "toy" for beginners. However, if desired, this device can always be slightly improved and made more convenient and efficient in operation.
