Metal detector with his own hands Terminator-3 from the md4yu forum: schemes and instructions
Metal detector - a specific tool. Not every user may need this interesting device, but still want to buy a metal detector or, as some call it, metal detector enough. Of course, you can find and buy a device, but why, if it is possible to do it yourself, according to the following scheme of the metal detector -Terminator 3.
On the Internet you can find a large number of schemes and instructions for making a metal detector with your own hands, but will be presented below ??one of the most popular variations of homemade devices of this type.
Simple and reliable metal detector Terminator-3
This version of the metal detector is called by many one of the most popular. The inventor of such a reliable device are the developers Yatogan and Radiogubitel - both users of the forum md4u.ru. On this forum, by the way, you can find a lot more interesting for those who want to assemble their own metal detector.
A few words should be said about that, that setting up and assembling this IB device will be very difficult for users, who have not done so before. We can say, which is even almost impossible. This can scare readers, but do not be afraid in any case.
Depth of detection:
- Five Russian rubles - 22-24 cm;
- Catherine's Penny - 27-30 cm;
- Helmet - approximately 80 cm;
- Beer can - up to a meter.
Depth calculated for chernozem with sensor, that has 240 mm on a wire. By the way, we can say a few words about the discrimination of this metal detector. The point is, that at that time, how many such devices are able to determine the location of a metal element at a certain depth, but can't find out what kind of metal it is, Terminator-3 copes with this task. It can detect most metal objects at the detection depth limit.
Assembly of the metal detector Terminator-3
To assemble and configure this device you will need to use the following devices:
- multimeter;
- oscilloscope;
- LC meter;
- generator;
- frequency meter.
Of course, if you buy the whole set of devices presented yourself, then have to spend. But you can try to create a virtual measuring system yourself on the basis of a regular personal computer. In Internet, by the way, you can find quite a number of programs for this purpose.
Scheme of a metal detector:
Terminator-3 metal detector is one of the most popular devices of this type. In essence, it is a typical coin, which has undergone some refinement, was able to detect gold, while ignoring other non-ferrous metals.
In addition, at least Terminator-3 and coin, he is also able to search for scrap metal, for which it is simply necessary to enter in the scheme a special mode of "all metals", since the scheme is taken first, on which this mode is absent.
Execution of the scheme is carried out with non-standard application of logic as the OP. Of course, there is a downside, which is, that the KU of the chips themselves is unknown, and the noise level is higher. You can apply domestic logic, but will have to put up with a larger range of parameters. It is possible, truth, perform replacement of the domestic chip of the sound generator, without harm and without additional problems.
By the way, Terminator-3 according to the following indicators, as the depth and accuracy of target identification, can be compared with models of branded brands, which are in the middle price range. Compared to cheaper branded counterparts, then Terminator-3 overtakes them in all respects. But so be it, you should assemble the metal detector properly, and not how it turns out.
Regarding the installation of the metal detector Terminator-3
To begin, you should pay attention to the nodes, marked on the diagram, as it is on them it is necessary to be guided later. This will come in handy during the setup process. When connected to the autogenerator transmission coil (TH) it begins to produce current fluctuations. These oscillations are in the form of a meander from the MC1 chip.
Then proceed to the receiving coil (RX), which also has current, given TX and creates a field. In this field, the coil should be balanced with TX. In other words, the RX field must be subtracted from the TX field. This will require a compensation coil (SH). According to different sensors, it appears differently: in the "RING" CX sensor - real, in the form of a coil, and in the DD CX sensor - virtual. It should be connected as follows, so that the current in it flows to the opposite side relative to the receiving coil. By gradually unwinding from the compensation coil, TX and RX current balance is achieved.
The balance is monitored by an oscilloscope, which allows to achieve the minimum amplitude at all positions of the handle in turn. When you reach a certain point, at which the amplitude begins to grow again, the tuning loop starts to operate, which is made from one end of the compensation coil. Before that, be sure to tune the TX and RX in frequency, at the same time, what rx is done on 100 Hz below, than TX. The coils are tuned to the desired frequency by connecting each of them in turn to the oscilloscope and the generator of the device.
CX frequency does not need to be adjusted. A situation is formed, in which the balance is disturbed if a metal object appears under the sensor, resulting in current running in the RX, which from there falls into the preamplifier, where it is then amplified and fed to the synchrodetector (SD), which, in turn, detects the phase of the incoming signal and outputs everything to the amplifier channels. In them everything amplifies and then gets to the MC8 comparator, whose task is to compare signal levels in the channels, then the comparator gives permission to operate the sound generator.
In principle, this is how almost all balancers work, truth, with slight differences. Differences, in many ways, concerning nuances with reconstruction of the metal detector from soil. In Terminator-3 reconstruction is phase.
Check the device board after the final soldering:
To check the board of the metal detector after soldering all the elements of the circuit, a number of procedures should be performed, which will determine whether the circuit was soldered correctly.
To do this, follow these steps:
-
To begin, you need to thoroughly rinse the board from the flux, which could stay there during soldering. It is highly undesirable to leave any redundancies on the board, otherwise you will have to face the unpleasant consequences of your negligence;
- Then turn on the power on the board, but not including the sensor;
- You need to unscrew the sensitivity knob by that time, when a steady beep sounds;
- Then just one finger touch of the sensor connector, for, to sound, issued by the speaker, interrupted for just a second. If this happened, it possible to praise yourself, since, if the sound broke, then you can be sure of that, that the board was soldered correctly.
- When the power is turned on, the diode must blink and go out. Otherwise, when the power is off, the diode should light up and gradually go out.
A few words should be said about battery discharge indications. It looks like this: the metal detector starts giving frequent signals at regular intervals. The diode must be lit constantly, and sensitivity drops sharply.
All settings for the frequency of the metal detector should be made with the same cable, with which the device will later be used. After, as the user has made all the necessary frequency settings, it must never be changed to the length of the cable.
Presented above ??picture, which describes the sensitivity of the device. Some data on several materials are given, which can be detected by this metal detector.
conclusion
In principle, to assemble such a metal detector is not difficult, So, this may require effort, time and money, but there are a number of advantages, which the user receives as a bonus, still collected this metal detector.
Terminator-3 is a very powerful device, if you compare it with branded models of metal detectors, and given that, that it can be made with your own hands, it makes it even nicer and better.
Of course, it will be much more difficult for the user to assemble such a device, if he does not have proper experience. But there are always guides and instructions for beginner radio amateurs, who will be able to find there a lot of interesting information for further work with electronics.
