08-02-2017, 05:40 PM
Abstract:
This magnetic impulse interacts with any passing object. But it can pick up magnetic pulses sent by other objects.1-Summary Metal detectors are machines of fascination. Sometimes though. Many of the people who use them are as enthusiastic about extolling the virtues of their favorite metal detector as it comes out in search of a buried treasure. The transmitting coil has an electric current that passes through it. There are two rings: an external coil called the transmitter coil and an internal coil called the receiving coil. The receiver coil amplifies these frequencies and sends them to the control box for analysis. The most commonly used metal detection technology is very low frequency (VLF). In this type of metal detector. This is the main means by which we determine how well we are doing our jobs. Making the object to create a weaker magnetic field of its own. Also known as induction balance. That creates an electromagnetic field. It is this magnetic pulse of the object that detects the coil of the receiver. Communication is difficult. The receiver coil is protected against the magnetic field of the transmitter coil. And what kind of things we need to do better.
Like a beep or a change of tone. This is where the transmission signal is generated and the receive signal is processed and converted into a destination response. The detected target is treasure.Concept Metal detectors work by transmitting an electromagnetic field from the search coil to the ground. Control box: The control box contains the detector electronics. Electromagnetic receiving field: The electromagnetic receiving field is generated from energized targets and is received by the search coil. Objective Response: When a good (accepted) target is detected, the metal detector will produce an audible response. Battery: The battery supplies power to the detector. Many Minelab detectors also provide a visual display of target information. Objective: A target is any metal object that can be detected by a metal detector. In this example. Special metal detectors are able to discriminate between different target types and can be configured to ignore unwanted targets. Electromagnetic Field of Transmission: The electromagnetic field of transmission activates the objectives so that they can be detected. The search coil of the detector receives the retransmitted field and alerts the user by producing a target response. Such as bottle caps. . Unwanted Target: Unwanted targets are usually ferrous (attracted by a magnet). Such as nails. If the metal detector is configured to reject unwanted targets, then there will be no objective response to those targets. But they can also be non-ferrous. Any metallic (white) object within the electromagnetic field will activate and retransmit an electromagnetic field of its own. That is a good goal (accepted). Coil Search: The search coil of the detector transmits the electromagnetic field to the ground and receives the electromagnetic return field of a target
The change in the magnetic field can be detected due to the metallic object. Government agencies and prisons help ensure that no one brings a weapon to the facility. And in the construction industry to detect reinforcing steel bars in the concrete and pipes and cables buried in walls and floors. Uses include demining (detection of landmines) .Introduction A metal detector is a metal-responding device that may not be readily apparent. With a range of uses ranging from leisure to work to safety. . And this produces a magnetic field of its own. If an electrically conductive metal part is near the coil. Consumer-oriented metal detectors offer millions of people around the world the opportunity to discover hidden treasures (along with lots of crap). Metal detectors are also used to detect foreign bodies in food. If another coil is used to measure the magnetic field (which acts as a magnetometer). office buildings. The parasitic currents will be induced in the metal. The detection of weapons such as knives and guns (especially in airport security). Metal detector technology is an important part of our lives. The simplest form of a metal detector consists of an oscillator that produces an alternating current that passes through a coil that produces an alternating magnetic field. Metal detectors at airports. The earliest detectors of industrial metals were developed in the 1960s and were widely used for mining and other industrial applications. Geophysical prospecting. Schools. Archeology and treasure hunting. The fact is that all these scenarios are valid
.COMPONENTS LIST
1 Resistors Specification 56kΩ 3.7kΩ 2.3kΩ 22kΩ 2.2kΩ 680E 15kΩ 2 3
Variable resistor Capacitors 5K3386Trim 1PF 1KPF 220PF 270PF 12KPF/100V 100/25V 4 5 6 7 8 9 10
Transistors
Diode
LED
Coil
Buzzer
Power supply
PCB BC 547 PH IN 4148
5MM Red Led
Metal Detector VK 27 CT (S)
9V Snapper
VK 557 PCB
Coil No of units 2 1 1 1 1 2 1 1 2 1 1 1 1 1 4 4 1 1 1 1 1 .