RU2756834C1 - Hand-held metal detector activated by casing - Google Patents

Abstract

FIELD: electronic equipment.SUBSTANCE: invention relates to manual metal detectors. The essence of the invention consists in the fact that a manual metal detector automatically switches to a state of reduced energy consumption or a switched-off state when it is placed in a case and automatically switches to a working state when it is removed from the casing.EFFECT: increase in the speed and productivity of searching for metal objects, an increase in the energy efficiency of the metal detector, an increase in the depth range when using the metal detector under water.3 cl, 4 dwg

Description

1. Field of technology

The present invention relates to hand-held metal detectors with a device for carrying and storing them, designed to detect objects made of non-ferrous and ferrous metals hidden in dielectric or weakly electrically conductive media and can be used in treasure hunting, archeology, in the field of security (personal search, inspection baggage or correspondence) and other areas.

2. Prior art

The present invention relates to hand held metal detectors. As a rule, such metal detectors are made in the form of a portable case intended for hand-held use, inside which is placed a primary transducer and electronics for detecting metal objects, as well as a power supply. Control and indication elements are placed on the surface of the case. Hand-held (portable) metal detectors are widely known and are available in a variety of designs.

Known hand-held metal detectors designed primarily for personal searches and public safety: "SPHINX" VM-311 [1], HAND DETECTOR WITH WIRELESS TRANSMISSION AND DATA RECEPTION [2], GARRETT SUPER SCANNER V [3], CEIA PD 240 [4 ].

Bibliographic data [1]: https://www.sphinx-md.ru/catalog/BM-311.html (date of access 09/01/2020).

Bibliographic data [2]: MANUAL DETECTOR WITH WIRELESS TRANSMISSION AND RECEPTION OF DATA [Text]: US Pat. 2714524 Rus. Federation: G01V 3/11 (2006.01) / Khairulin Alexander Abdulmyanovich (RU), Khairulin Sergey Alexandrovich (RU), Khairulin Pavel Alexandrovich (RU), Kryukov Alexander Sergeevich (RU); patent holders: Khairulin Alexander Abdulmyanovich (RU), Khairulin Sergey Alexandrovich (RU), Khairulin Pavel Alexandrovich (RU), Kryukov Alexander Sergeevich (RU); -No.2019116876, 05/31/2019; publ. 02/18/2020 Bul. No. 5.

Bibliographic data [3]: https://garrett.com/security/hand-held/super-scanner-v-hand-held-metal-detector (date of access 09/02/2020).

Bibliographic data [4]: https://www.ceia.net/security/product.aspx?a=PD240 (date of treatment 09/02/2020).

In this description, the terms "metal detector", "metal detector", "metal detector", "pinpointer" are synonymous.

Also widely known are hand-held metal detectors designed and mainly used in treasure hunting and archeology: METAL FINDER (PINPOINTER) SPHINX 01 [5], METAL DETECTOR WITH HERMETIC HOUSING [6], XP MI-6 [7].

Bibliographic data [5]: https://www.sphinx-md.ru/catalog/nHHnoHHTep.html (date of access 09/02/2020).

Bibliographic data [6]: METAL DETECTOR WITH HERMETIC HOUSING [Text]: application 14582455: G08B 3/00, G08B 5/00, G08B 7/00, G01D 5/12, H04R 1/02 / Gerald L. Johnson (US) , Robert J. Podhrasky (US), Brent C. Weaver (US); applicant: Garrett Electronics (US); - publication number US 9347798; app. 12.24.2014; publ. 05/24/2016; publication type B1.

In addition, information about METAL DETECTOR WITH HERMETIC HOUSING is presented on the manufacturer's website at the link: https://garrett.com/sport/pro-pointer/pro-pointer-at (date of treatment 09/02/2020).

Bibliographic data [7]: http://www.xpmetaldetectors.com/metal-detector/mi-6/ (date of treatment 09/02/2020).

Structurally and functionally, all of the listed known hand-held metal detectors are similar. All of them contain a housing made of thermoplastic material, intended for manual use, inside which there is an electrical circuit of a metal detector, which includes a primary transducer and creates an electromagnetic field, when a metal object appears in which an alarm signal is generated (eddy current method for detecting the presence of metal objects). There is also a battery in the case. The controls are brought out to the surface of the case and are mechanical buttons or switches.

All mentioned handheld metal detectors can be in two functional states: search state and low power state. The transition between these states is carried out exclusively by means of manual control - by pressing a mechanical button or switch. The search state is the operating state of the instrument in which metal objects are detected when they appear in the control area of the metal detector. This state is characterized by the maximum power consumption of the device. A low power state is a state in which the metal detector is unable to detect metal objects and is characterized by the lowest power consumption of the instrument. Some appliances transition to an off state instead of a low power state. The difference between the low power state and the off state is that in the off state all metal detector units are de-energized and the power supply is not consumed. In a low-power state, the metal detector units continue to function in "sleep" mode or are partially de-energized. The advantage of the low power state over the off state is a shorter transition time of the device into an operating state due to the complete or partial absence of transients in the power circuits. In this case, the off state is more energy efficient.

Typically, to conserve energy for the power source of the metal detector, the user switches the metal detector from one state to another and vice versa. For example, when providing security in order to save energy, the user can turn off the device when personal search is not required and turn on (put into the search state) when it is necessary to quickly carry out a search. With a large number of people being searched, the process of manually transferring a metal detector from one state to another can take up a significant part of the time that could be spent directly on the inspection and thereby increase the user's productivity. Often, for this purpose, the user does not intentionally switch the metal detector off, even when no inspection is required, which negatively affects the energy efficiency of the metal detector.

In the field of treasure hunting, the problem is no less acute, since the result directly depends on the search performance. As a rule, in treasure hunting, portable hand-held metal detectors are auxiliary devices and are placed in a separate class, the name of which is "pinpointers". The user searches with a hand-held metal detector with a rod, which has a larger scanning area than a hand-held metal detector. A handheld metal detector is used to locate a metal object detected by a metal detector on a rod. The less time the user spends on manipulations related to the control and adjustment of the handheld metal detector, the more area he can explore in the same time.

Thus, the need to manually switch the device from the search state to the off state (low power state) and vice versa to save energy of the power source can be attributed to the vulnerable indicators of the known hand-held metal detectors.

In addition, the aforementioned treasure hunting metal detectors [5], [6] and [7] have a degree of protection against penetration of foreign objects and water, corresponding to IP68, which makes it possible to use these devices under water. The permissible immersion depth is determined by the manufacturer and is limited by the depth at which the control buttons of the metal detector are clamped under the influence of water pressure. As a rule, the depth at which such a metal detector can be used does not exceed 12 m. Thus, the use of mechanical buttons as controls for hand held metal detectors and the lack of alternative control methods limit the depth range when using the metal detector underwater.

The overwhelming majority of manufacturers of hand-held metal detectors offer special devices for carrying and storing them complete with devices, the so-called cases (holsters, clips, cases, etc.), allowing you to carry and store the metal detector when not in use. In this description, the terms "cover", "holster", "clip", "case", "pocket" are synonymous and are united by the concept of "cover" - a device for carrying and storing a hand-held metal detector, as well as having the ability to perform special functions. The covers have various configurations and for ease of use can be attached to the user's belt (for example, LEATHER FIXING FOR COMFORTABLE WEAR ON A BELT [8] or BELT HOLDER [9]), on the leg (for example, COBURA FOR PINPOINTER [9]), on a hand-held metal detector with a barbell (for example, PP CLIP STEM [10]) or be part of a bag (for example, an OPEN FIND BAG WITH PINPOINTER COMPARTMENT [11]).

Bibliographic data [8]: https://www.sphinx-md.ru/aksessuary/ (date of treatment 09/07/2020).

Bibliographic data [9]: https://garrett.com/security/hand-held/super-scanner-v-hand-held-metal-detector (date of access 09/07/2020).

Bibliographic data [10]: http://www.xpmetaldetectors.com/metal-detector/category/accessories-deus/ (date of access 09/07/2020).

Bibliographic data [11]: http://xp-russia.ru/aksessuari/ryukzaki-sumki/sumka-dlya-nahodok-otkritaya-s-otdeleniem-dlya-pinpointera/ (date of access 07.09.2020).

All known cases for hand-held metal detectors have a single function of carrying and storing the metal detector, which is in no way related to the operation of the device. This fact can be attributed to the vulnerable indicators of well-known covers. As a rule, when searching for metal objects, the user acts according to the following algorithm, regardless of the scope of the metal detector:

1. removing the metal detector from the case;

2. manual activation of the metal detector (manual transfer of the metal detector to the search state);

3. search for a metal object;

4. manual shutdown of the metal detector (manual transfer of the metal detector to a state of reduced power consumption);

5. placement of the metal detector in the case.

Automatic switching on and off of a manual metal detector when it is removed and placed in a case, respectively, will allow to exclude items 2 and 4 from the user's work algorithm and thereby significantly save time searching for metal objects and increase the energy efficiency of the device, as mentioned earlier. To implement this technical solution, it is necessary to have a connection between the case and the hand-held metal detector, thanks to which the metal detector can unambiguously determine whether it is in the case or not.

Some known cases have metal elements in their construction that will affect the operation of the metal detector if it is placed in the case when it is switched on. But the use of signals from the metal elements of the cover for the automatic transfer of the metal detector from an operating state to a state of low power consumption and back is not possible due to their identity with the signals from the detected metal objects during the search.

The closest solutions in terms of the technical essence and set of technical features are inspection MANUAL METAL DETECTOR [12] and BELT FIXING [13].

The MANUAL METAL DETECTOR, in addition to the electrical circuit that provides the detection of metal objects, contains an accelerometer, which automatically determines when the metal detector is used directly for inspection operations (is in motion), and when the metal detector is not in use (at rest). In the case when the metal detector is at rest (inspection is not carried out), on a signal from the accelerometer, the microcontroller turns off the power supply to the main part of the circuit, thereby significantly reducing power consumption.

Bibliographic data [12]: MANUAL METAL DETECTOR [Text]: pat.175760 Ros. Federation: G01V 3/11 (2006.01) / Aleev Timur Marsovich (RU); applicant and patentee: Aleev Timur Marsovich (RU); - No. 2017121519; app. 06/19/2017; publ. 12/18/2017 Bul. No. 35.

The key feature that neutralizes the effect of reducing energy consumption with the use of the accelerometer is that for the accelerometer the process of inspection and the fact that the metal detector is moving are equivalent processes. In many cases (for example, between inspection processes or, in the area of treasure hunting, at the time of using a hand-held metal detector with a rod), the user stores the hand-held metal detector in a case fixed to the body. Thus, the metal detector is always in motion, even when no inspection is being carried out, and the transition to a low power consumption mode is not possible.

BELT FIXING is a cover made of composite materials that can be attached to the user's waist belt using a textile fastener and provides the ability to carry and store the handheld metal detector. In addition, the BELT MOUNT has a metal ring that allows you to attach the hand-held metal detector's tripod to reduce the chance of losing the instrument.

Bibliographic data [13]: https://www.sphinx-md.ru/catalog/Pinpointer.html (date of access 07.09.2020).

As with the previously described cases, a vulnerable BELT FIXED metric is the lack of communication between the case and the handheld metal detector, allowing the detector to determine whether it is in the case or not.

3. Disclosure of the essence of the invention

The task of the technical solution is to create a hand-held metal detector that automatically switches to a state of reduced power consumption or off when it is placed in a case and automatically switches to an operating state when it is removed from the case.

The technical result consists in:

- increasing the speed and productivity of searching for metal objects due to the lack of actions aimed at manually turning on and off the metal detector by the user during the operation of the device;

- increasing the energy efficiency of the metal detector by automatically switching to a reduced power consumption mode;

- increasing the range of depths when using the metal detector under water due to the absence of the need to use mechanical buttons, which remain in the pressed position when exposed to water pressure.

The technical result is provided by the fact that the MANUAL METAL DETECTOR ACTIVATED BY THE CASE includes a primary transducer, an electronic circuit of a metal detector, a power source located in a portable case, and a case that contains an element that activates the automatic transition of the metal detector to a state of reduced power consumption or shutdown when the metal detector is placed in a case without additional user actions and automatic transition to a working state when removing the metal detector from the case without additional user actions. At the same time, the metal detector contains a unit for determining the location and removing the metal detector from the case for automatic transition to a state of reduced power consumption or shutdown when the metal detector is placed in the case without additional user actions and for automatic transition to an operating state when the metal detector is removed from the case without additional user actions.

In special cases, the block for determining the room and removing the metal detector from the case may include:

- a magnetically sensitive system, while the cover contains an activating element in the form of a magnetic field source.

- at least one sealed mechanical control, wherein the cover contains an activating element that mechanically acts on the control when the metal detector is placed in the cover.

4. Brief Description of Drawings

The design and principle of operation of the MANUAL METAL DETECTOR, ACTIVATED BY THE CASE, is illustrated by the following figures:

FIG. 1 shows a block diagram of a hand-held metal detector;

FIG. 2 is a General View of a Handheld Metal Detector;

FIG. 3 is a General View of the Carrying and Storing Carrying Case for the Handheld Metal Detector;

FIG. 4 is a General view of a hand held metal detector placed in a case, where:

1 - inductance coil of the primary converter of the metal detector; 2 - autogenerator; 3 - amplitude detector; 4 - microcontroller; 5 - power supply; 6 - voltage stabilizer; 7 - block for determining the room and removing the metal detector from the case; 8 - manual control and indication unit; 9 - metal detector housing made of thermoplastic material; 10 - search element of the corpus; 11 - battery compartment cover; 12 - metal detector control button; 13 - sound chamber; 14 - stiffener; 15 - an eyelet for attaching a trainer; 16 - light guide; 17 - magnetosensitive system; 18 - printed circuit board; 19, 20 - Hall converter 1, Hall converter 2, respectively; 21 - cover loop; 22 - cover base; 23 - metal ring for attaching the metal detector trench; 24 - the place of installation of the magnet; 25 - cover; 26 - hand held metal detector.

5. Implementation of the invention

The metal detector is made in a portable case intended for manual holding, inside of which there are an electronic circuit of the metal detector, a primary eddy current transducer with at least one detecting inductance coil, a power source and a unit for determining the location and removing the metal detector from the case. The primary eddy-current transducer can be made absolute or transformer, differential or parametric. A compartment is made in the handle of the detector to accommodate a rechargeable or disposable power supply. On the outer side of the housing there is at least one manual control for the metal detector. A mechanical tact button, a touch button, a rocker switch, etc. can be used as a manual control element. The manual control element can be used to turn on / off the metal detector, select its operating mode, select the sensitivity level, turn on / off the flashlight, etc. several manual controls, each with a different function.

Light-emitting diodes, sound and tactile indicators in various combinations and designs can be used to indicate the operating modes of the metal detector and indicate the presence of metal objects.

The cover is made in the form of a rigid plastic base, trimmed with synthetic fabric and a synthetic fabric loop, fixed on the base, into which a hand-held metal detector is placed. The loop is tapered to prevent the detector from falling out of the case. On the back of the base there is a textile fastener or a metal clip for attaching the cover to a waist belt and other items of clothing, finds bags or hand-held metal detectors with a barbell. In addition, on the base of the case, a metal detector trench attachment is provided to prevent its loss. It is possible to design a cover with adjustable length straps made of synthetic fabric or leather for attaching to the leg. The case is also available as part of a finds bag. In this embodiment, the cover is a part of the bag and the surface of the bag, on which the loop is fixed, serves as the basis for it. For the manufacture of the cover, natural fabric, synthetic fabric, natural leather, artificial leather, plastic in various combinations can be used.

In contrast to the known technical solutions in the HAND-HELD METAL DETECTOR ACTIVATED BY THE CASE, there is a connection between the hand-held metal detector and the activating case, due to which the metal detector can uniquely determine whether it is in the case or not.

HAND-HELD METAL DETECTOR ACTIVATED BY THE CASE includes a primary transducer, an electronic circuit of the metal detector, a power supply located in a portable case, as well as a case that contains an element that activates the automatic transition of the metal detector to a state of low power consumption or shutdown when the metal detector is placed in a case without additional user action and automatic transition to working state when removing the metal detector from the case without additional user action. At the same time, the metal detector contains a unit for determining the location and removing the metal detector from the case for automatic transition to a state of reduced power consumption or shutdown when the metal detector is placed in the case without additional user actions and for automatic transition to an operating state when the metal detector is removed from the case without additional user actions.

In special cases, the block for determining the room and removing the metal detector from the case may include:

- a magnetically sensitive system, while the cover contains an activating element in the form of a magnetic field source.

- at least one sealed mechanical control, wherein the cover contains an activating element that mechanically acts on the control when the metal detector is placed in the cover.

Various technical implementations of the connection between the hand held metal detector and the case are possible, but the ones listed below are the most reliable during operation:

1.mechanical;

2. eddy current;

3. magnetic;

4. radio frequency;

5.acoustic magnetic.

Mechanical connection. With this method of communication, at least one metal ring is installed in the loop of the case, which closes two contacts brought out to the surface of the case of the hand-held metal detector when it is placed in the case. Thus, the contacts are in the closed position when the metal detector is in the case, and in the open position when the metal detector is removed from the case. The advantages of this communication method are ease of implementation and energy efficiency. The disadvantages include corrosion and abrasion of metal contacts over time, increased requirements for ensuring the cleanliness of contacts, as well as the inability to operate the metal detector under water.

Another mechanical method of realizing the connection between the hand-held metal detector and the cover is possible, which consists in the implementation of mechanical action on the manual controls of the metal detector by the structural element of the cover. Sealed switches, switches, sliders and other elements that do not lose their functionality under water with increasing depth can be used as manual controls. The advantages of this communication method are also ease of implementation, energy efficiency and the possibility of using it under water. Disadvantages of the method: increased requirements for the reliability and tightness of manual controls due to constant mechanical contact with the cover.

When using a mechanical connection, it is possible to transfer the metal detector not only to a state of reduced power consumption, but also to an off state.

Eddy current communication. To implement this communication method, several electrically conductive objects are installed in the cover, which affect the primary eddy-current transducer of the metal detector when it is in working condition. The objects are preferably positioned at the base of the sheath along the path of the handheld metal detector as it is placed in the sheath. Thus, during the process of placing the metal detector in working order in the case, electrically conductive objects located in the case create a unique signal, by which the electronic circuit of the metal detector determines that the device is placed in the case. The advantage of this method is the simplicity of implementation, since in order to receive signals from electrically conductive objects located in the case, no changes are required in the circuitry of the metal detector, contactlessness and the possibility of using it under water. The disadvantage of this method is its low energy efficiency, since the constant generation of an electromagnetic field is required to track the moment of removing the metal detector from the case and automatically switch to the operating state.

Magnetic connection. To implement the magnetic connection, a permanent magnet is installed in the case, preferably in the base. The handheld metal detector is equipped with a magnetically sensitive system, the sensitive elements of which are located inside the metal detector housing in that part of it that is opposite the permanent magnet installed in the case when the device is placed in the case. Thus, when the metal detector is placed in the case, the magnetically sensitive system detects the presence of a constant magnetic field created by the case magnet and generates a signal that can be used by the electronic circuit of the metal detector to recognize the case and put the metal detector in a reduced power state. When removing the metal detector from the case, the magnetic field acting on the magnetosensitive system disappears, which leads to the transfer of the metal detector to the operating mode. Hall transducers, magnetoresistive transducers, reed switches, etc. can be used as sensitive elements of a magnetically sensitive system. The advantages of the magnetic method for realizing the connection between the hand-held metal detector and the case are: contactlessness, energy efficiency, relative ease of implementation and the possibility of using it under water. The disadvantages include the directionality of magnetosensitive elements, requiring their strict orientation relative to the direction of the magnetic flux of a permanent magnet located in the case. In this case, in order for the magnetically sensitive system to reliably record the presence of the magnetic field of a permanent magnet installed in the case, for any orientation of the metal detector, it is preferable to install several magnetically sensitive elements with different orientations in space.

When using a magnetic connection, it is possible to transfer the metal detector not only to a state of reduced power consumption, but also to an off state (when using reed switches).

Radio frequency communication. To implement the radio frequency communication method, the so-called automatic identification of objects (English Radio Frequency Identification or RFID) is used. Any RFID system consists of a reader and an RFID tag. An RFID tag is a miniature device that consists of an antenna and a chip that stores data. The tag does not contain a power source and is powered by electromagnetic radio frequency radiation from the reader. Unlike RFID tags, the reader requires an external power source. The reader is a radio frequency signal generator that acts on the tag to write and read the data stored in the RFID tag.

For a CASE-ACTIVATED HAND-HELD METAL DETECTOR, the RFID tag fits into the case, preferably the base, and the reader into the hand-held metal detector. When the latter is placed in the cover, the cover is identified by the metal detector, and if the mark installed in it is recognized, the metal detector goes into a state of reduced power consumption. The advantages of this method are contactlessness, the ability to use underwater and increased reliability of the case recognition, since the RFID tag contains a unique identification number, the probability of repetition of which in other systems is close to zero. The disadvantage of this method is not high energy efficiency, since in order to track the moment of removing the metal detector from the case and automatically switch to an operating state, it is required to track the presence of an RFID tag by the reader (constant or periodic generation of radio frequency signals).

Another embodiment of the radio-frequency method is the use of a parallel high-Q resonant circuit consisting of an inductor and a capacitor as a label placed in a cover. In this case, a radio signal generator is additionally built into the hand-held metal detector, the frequency of which coincides with the resonant frequency of the circuit located in the case. When the metal detector is placed in the case, the resonant circuit changes the parameters of the generated radio signal, which is recorded by the radio signal receiver and is a signal for the transition to a state of reduced power consumption. This method of realizing the connection between the hand held metal detector and the case has the same disadvantages and advantages as RFID technology, however, it is more advantageous from an economic point of view.

Acoustic magnetic communication. This method of implementing a connection between a hand-held metal detector and a case is similar in principle to the last version of the radio frequency method, but as a tag, two miniature metal strips are used, one of which is made of solid magnetized metal and rigidly attached to the plastic case of the tag, and the second is made of amorphous ferromagnetic metal capable of mechanically vibrating (acoustomagnetic mark). In an alternating electromagnetic field emitted by a generator built into a metal detector, a metal strip with this property vibrates at the frequency of the field. The vibration amplitude will be especially high if the frequency of the alternating electromagnetic field coincides with the resonant (acoustic) frequency of the metal strip. In this case, the resonating strip creates its own electromagnetic field and continues to vibrate independently for a short period of time after the disappearance of the external electromagnetic field. For this reason, the generator operates in a pulsed mode, and the signal from the tag is recorded by a receiver also built into the metal detector between the pulses of the generator. This method of realizing the connection between the handheld metal detector and the case has the same disadvantages and advantages as RFID technology.

6. Best Mode for Carrying Out the Invention

Design. A HAND-HAND METAL DETECTOR contains one inductor (1) wound on a ferrite core, which is used as a parametric eddy-current transducer, an auto-generator (2), an amplitude detector (3), a microcontroller (4), a manual control and display unit (8), a voltage stabilizer (6), a power source (5) and a unit for determining the location and removing the metal detector from the case (7), combined in a single portable case (9), adapted for hand-held use.

The eddy current transducer is connected to an autogenerator (2), the output of which is connected to the input of the amplitude detector (3), the output of which is connected to the first input of the microcontroller (4). The first output of the microcontroller (4) is connected to the first input of the oscillator (2) for its adjustment. The power supply (5) is connected to the input of the voltage stabilizer (6), the first output of which is connected to the second input of the autogenerator (2), the second output to the second input of the microcontroller (4), and the third output to the first input of the manual control and display unit ( eight). The second output of the microcontroller (4) is connected to the second input of the manual control and display unit (8), the output of which is connected to the third input of the microcontroller (4). The output of the unit for determining the room and removing the metal detector from the case (7) is connected to the fourth input of the microcontroller (4), and the input is connected to the fourth output of the voltage stabilizer (6).

The eddy current transducer is located in the search element of the housing (10), which allows free scanning of the controlled surface.

The power supply (5) is placed in the back of the case, intended for manual holding (the handle of the case) and closed by the battery compartment cover (11). The tightness between the battery compartment cover (11) and the housing (9) is ensured by an O-ring.

In the part of the case, located between the battery compartment and the search element, the electronic circuit of the metal detector is located. The metal detector is controlled using one button (12) located in the manual control and display unit (8).

Directly under the niche of the sound chamber (13) containing the membrane, there is an electromagnetic acoustic transducer, which is part of the manual control and display unit (8). The frequency of the vibration signal entering the acoustic transducer is set by the microcontroller (4).

In the place where the search element (10) adjoins the handle of the metal detector, there is a light guide (16) passing through a through hole in the housing (9). The tightness between the light guide (16) and the housing (9) is ensured by an O-ring. Inside the case, next to the light guide (16) on the board (18), there are two light-emitting diodes that are part of the manual control and display unit (8), one of which has a white glow color, and the second is two-color and has a green and red glow. ... The use of a combination of light-emitting diodes of the described type makes it possible to realize not only the function of a flashlight for illuminating the search area or a found metal object in low light conditions, but also to obtain maximum information content about the operating modes of the device. To minimize electrical energy consumption, it is preferable to use ultra-bright light-emitting diodes in conjunction with a pulse power supply.

On the outer surface of the body (9), in its rear part, there is an eyelet for attaching the trainer (15). In addition, on the outer surface of the body (9), in its most fragile and exposed to external mechanical stress part (along the search element (10)), there is a stiffening rib (14), passing to the front end of the body (9). The stiffener (14) has a variable height along the search element and has the greatest strength near the front end of the body (9).

The ACTIVATING COVER (25) consists of a rigid plastic base (22) covered with synthetic fabric and a synthetic fabric loop (21) fixed to the base (22), into which a hand-held metal detector (26) is placed. The loop has a conical shape, which prevents the metal detector from falling out of the cover (25). On the back of the base there is a textile fastener for attaching the cover (25) to a waist belt and other items of clothing, finds bags or hand-held metal detectors with a barbell. In addition, a metal ring (23) is provided at the base of the case for attaching the metal detector train to prevent loss.

From the point of view of reliability and energy efficiency, the best option for the connection between the handheld metal detector and the case is magnetic coupling, therefore a permanent magnet is installed in the base of the case (24). The most common types of permanent magnets are neodymium and ferrite magnets. Neodymium magnets have a higher residual induction for the same size of magnets. But the use of a neodymium magnet negatively affects the properties of the ferrite core of the parametric eddy-current transducer of the metal detector. Therefore, an extended ferrite magnet with dimensions of 50x15x3 mm is installed in the case. A magnet length of 50 mm along the Y-axis of the metal detector in FIG. 2 eliminates the possible difference in the "depths" of entry of the metal detector (26) into the cover (25) along the Y axis.

The unit for determining the room and removing the metal detector from the case (7) contains a magnetosensitive system (17), and omnipolar Hall digital converters (19, 20) are used as magnetically sensitive elements. The main advantages of Hall converters of this type are ease of integration into the circuitry of a metal detector, low cost, absence of mechanical contacts, and high sensitivity to a magnetic field. To exclude the influence of orientation (rotation by angle a in Fig. 2) of a hand-held metal detector when it is placed in a case in a magnetically sensitive system, two Hall transducers PX 1 (19) and PX 2 (20) are used, the planes of which are mutually perpendicular. PX 1 and PX 2 are located in the ZX plane in the center of the device so that PX 1 registers the X-component of the magnetic field, and PX 2 - the Z-component of the magnetic field. Thus, at any angle a, at least one of the two Hall transducers will determine the presence of an external magnetic field of the magnet placed in the case.

Description of device operation

The principle of operation of the metal detector is based on the harmonic eddy current method of detecting hidden metal objects. When a metal object appears in the control zone of the search element (10) of a metal detector, the object begins to be affected by a primary alternating electromagnetic field. Since all types of metals (non-ferrous and ferrous) have high electrical conductivity, eddy currents are generated in the object under the action of the primary field, creating a secondary electromagnetic field that changes the amplitude of the harmonic signal of the oscillator (2). This change is detected by an amplitude detector (3) and recorded by a microcontroller (4). If the change in amplitude is greater than a predetermined fixed value, then a metal object detection alarm is triggered.

The metal detector is controlled with a single button (12). To turn on the device, press the button (12) once. After switching on the device, the two-color light-emitting diode lights up green and signals the presence of power. When a metal object appears near the search element, an audible and / or tactile alarm is triggered. The sound signal has a constant sound frequency, but the repetition rate of sound or tactile signals increases as the search element approaches the metal object. If a metal object has a large area or is close to the search element, the sound or tactile signal becomes constant. When the metal object is removed from the search element, the metal object detection alarm is turned off.

To change the signaling method (sound and tactile or only tactile) and the sensitivity level, press and hold the button in the on state until the second sound signal appears. Release the button. The metal detector is in the menu for selecting the signaling method and sensitivity level. Switching of all possible modes is carried out "in a circle" by pressing the button once. After selecting the required mode to exit the menu, you must wait for the appearance of a sound signal, indicating the exit from the menu and the transition of the metal detector to the operating state with the selected signaling method and sensitivity level.

The metal detector has three fixed sensitivity levels and one user configurable. To switch to the custom sensitivity level setting mode, press and hold the button in the on state until the third sound signal appears. Release the button. The metal detector is in the custom sensitivity setting mode. To set a custom sensitivity level, take a metal object to be searched for, or its equivalent in size and electrical conductivity, and bring it to the search element (10) at the required detection distance, then press the button (12) once. The custom sensitivity level will correspond to the distance the target was at when the button was pressed. Next, turn off the metal detector by holding the button until the first sound signal. In this case, the user sensitivity level is stored in the non-volatile memory of the microcontroller (4).

When searching for metal objects in heterogeneous media containing inclusions with low electrical conductivity (for example, ground mineralization), false alarms can occur. To minimize the influence of the environment on the operation of the metal detector, the device has a function of "detuning" from interfering factors, for example, from the ground, carried out by a single press of the button in the switched on state in the environment where the search is performed. With a single press of the button, the electronic circuit of the metal detector adjusts to the current environmental conditions (for example, to the current level of ground mineralization) and continues to work relative to these conditions.

To activate / deactivate the function of automatic transition to the state of reduced power consumption when the metal detector is placed in the case without additional user actions and the automatic transition of the metal detector to the working state without additional user actions, press and hold the button in the working state until the fourth sound signal appears. Release the button. The function is activated if it was previously deactivated and vice versa. You can check if the auto hibernation function is activated by placing the metal detector (26) in the carrying case (25). If the function is activated, when the handheld metal detector is placed in the case, the metal detector emits a short beep and tactile signal and goes into a low power state. If the function is deactivated, then the metal detector, when placed in the cover, remains in working condition and can signal the detection of electrically conductive structural elements of the cover or the place where it is fixed.

When the hand-held metal detector (26) is placed in the cover (25), the magnetically sensitive system (17) of the metal detector is located opposite the permanent magnet located at the base of the cover (24), while at least one of the Hall transducers (19, 20) at the output appears a signal indicating that the metal detector has been placed in the case. This signal is processed by the microcontroller (4) and, if the automatic hibernation function is activated, the microcontroller will put the metal detector into a hibernation state. In this state, the microcontroller is in sleep mode and it is awakened only when the signal from the Hall converters disappears. After waking up (removing the metal detector from the case), the microcontroller (4) adjusts the auto-generator (2) and puts the metal detector into working condition.

An additional feature of this feature is the expansion of the depth range when using the handheld metal detector underwater. When diving to a depth of more than 7 m, activate the automatic transition to a low power state, and then place and remove the metal detector from the case 3 times within 5 seconds. In this case, three signals from the magnetically sensitive system (17) will be sent to the microcontroller input (4) within 5 seconds. Under this condition, the metal detector will stop responding to pressing the button (12) under the influence of water pressure. "Detuning" from interfering factors in this mode is carried out automatically each time the metal detector is removed from the case. In order for the metal detector to become susceptible to pressing the button (12), you should also place and remove the metal detector from the case 3 times within 5 seconds.

To turn on / off the flashlight, it is necessary to press and hold the button in working condition until the light-emitting diode with a white glow is turned on / off.

To turn off the device, it is necessary to press and hold the button in working condition until the first sound signal appears. The operating mode of the metal detector is remembered when turned off and automatically restored when turned on.

If the device is not used for a long time (there are no button presses and no metal actuation), then after 5 minutes the alarm function is activated in case of loss - within 40 minutes the device signals its location by sound signals of different sound frequencies once every 10 seconds, when In this case, the battery discharge is ignored, after which it turns off.

The metal detector is powered from a power supply of the "Krona" type with a rated voltage of 9V. When the battery is discharged to 7.5V, the two-color light-emitting diode starts to shine with yellow light. When the supply voltage drops to 7V, the two-color light-emitting diode starts to shine in red. When the supply voltage drops below 6.8V, the metal detector turns off automatically.

The working frequency is 12 kHz. The probability of detection is 0.98. The current consumption in the operating state of the search is 7.5 mA. The current consumption in the state of reduced power consumption is 0.5 mA. Weight - 0.16 kg. Dimensions - 231 × 45 × 41 mm. Operating temperature range - -37 ... + 70 C °. Degree of protection against penetration of foreign objects and water - IP68. The maximum dive depth without using the auto hibernation function is 7 m. The maximum diving depth with the auto hibernation function is 30 m.

Claims (3)

1. Hand-held metal detector, activated by a cover, including a primary transducer, an electronic circuit of the metal detector, a power source located in a portable case, and a cover, characterized in that the cover of a hand-held metal detector contains an element that activates the automatic transition of the metal detector to a state of low power consumption or off when placing the metal detector in the case without additional user actions and automatic transition to the operating state when removing the metal detector from the case without additional user actions, while the metal detector contains a unit for detecting a room and removing the metal detector from the case for automatic transition to a low power state or off when the metal detector is placed in cover without additional user actions and for automatic transition to a working state when removing the metal detector from the cover without additional user action. 2. A hand-held metal detector activated by a cover according to claim 1, characterized in that the unit for detecting the room and removing the metal detector from the cover includes a magnetosensitive system, and the cover contains an activating element in the form of a magnetic field source. 3. Hand-held metal detector activated by a cover according to claim 1, characterized in that the unit for detecting the room and removing the metal detector contains at least one sealed mechanical control, and the cover contains an activating element that mechanically acts on the control when the metal detector is placed in the cover.

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