Metal Detector Circuit OverviewThemetal detector circuitis an electronic circuit that is specifically designed to detect metal that lies deep in the water or soil. In addition to these objectives are specifically designed for screening or security purpose and to search for mines. Even in the industrial metal detector circuits are used as pharmaceuticals, and food processing, packaging and plastics industry, textiles and chemicals. Metal detector is an important tool to check for metal debris for food to avoid food poisoning.
Various types of metal detectors on the market, basically metal detector consists of three types are adopting technology used as VLF, BFO, and Pulse Induction (PI) technology. A description of the metal detector technology will be described briefly along with metal detector circuit examples as below.
Very Low Frequency (VLF) Metal Detector CircuitVLFmetal detector circuituses the most common technology. Metal detector consists of a set of two, which is the receiver and transmitter coil. Receiver coil sends an electric current, and creates a magnetic field pressed to the ground continually, and transmitter coil retracts the magnetic field. The magnetic field is produced by reacting to a metal detector in a metal or a conductor that passes over it. Electric current and magnetic field formed around the conductor, when the object is found.
Receiver coils should only be influenced by the conductor and / or a metal object’s magnetic field itself. So that these coils should be protected from the influence of magnetic fields produced by the transmitter coil. Electricity that runs on the receiver coil generates a weak magnetic field when a conductor is closer to the metal detector. In turn coil will amplify and transmit electrical frequencies that have the same frequency with the magnetic field emanating from the metal to make the analysis in the control box. Through this, the VLFmetal detector circuitthat works on very low frequency (VLF) will be able to determine the difference between the types of metal, the depth of the current position is detected. Here for more information about VLF Metal Detector Circuit.
Pulse Induction (PI) Metal Detector CircuitOn the Pulse Induction (PI) Technology, metal detector circuit have a decent single coil is used on both the receiver and transmitter, although it also allows use of up to 3 coils. Metal detectors can send a short burst and / or pulses of current in the coil that will produce a magnetic field is shorter. The magnetic field generated in each pulse will reverse the polarity and will eventually collapse. Electrical surge can be created and will take place in a very short time. When the magnetic field, pulse and spike collapses, a known current called as reflected pulse will occur and into the coil, it will run. This reflected pulse can only last in seconds.
When a metal or a conductor will get in contact with a metal detector, the pulse is reflected to survive in a longer time. The reason of this is caused by an opposing magnetic field produced by the metal detector. Metal detector is a device that has an integrator circuit which contains a sample that can be monitored closely on each spike. It is to convert the signal, reads and amplifies the signal will change into a direct current. Audio circuit is connected when getting the right amount of electricity will produce tones that indicate the presence of metal objects.
Source: Pulse Induction Metal Detector – GoldPic 3
Beat Frequency Oscillator (BFO) Metal Detector CircuitThe beat frequency oscillator is like the VLF (very low frequency) that uses two-wire coils. The first coil of the device can be found in the control box, and in the search head lays the second coil. The first coil which can be found in the control box most of the time is smaller compared to the second one in the search head. The two coils, on the other hand, stay connected in the oscillator that sends an out number of thousand electric pulses per second. When the pulse passes through every coil radio waves can be created and the receiver that can be found in the control box collects them all.
After this you will hear clear tones like the radio wave frequency which is created by the receiver. The current of electricity that is moving in the coil in the search head will create a field of the magnet that creates a new field of the magnet around the metallic object as the metal detector passes over the metals. The creation of radio waves from the search head coil is being interfered by the magnetic field created by the metallic objects. This produces a change of tone in the receiver these changes can help in detecting the object in being targeted.
Source: How to Make a Metal Detector -? Easy Treasure.
Visit a useful link for BFO Metal Detector Circuit – Bob Data.
So at a glance info about the metal detector circuit but technological developments will continue to develop the tools that help enhance any easier everything in human life. Homemade simple metal detector would help you to know better in a metal detector circuit.
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