04-11-2012, 12:18 PM
i wanna kno the working of metal detector with the help of
vk557
04-11-2012, 12:18 PM
i wanna kno the working of metal detector with the help of vk557
05-11-2012, 12:38 PM
to get information about the topic "vk 557 metal detector " full report ppt and related topic refer the link bellow
https://seminarproject.net/Thread-metal-...ort?page=5 https://seminarproject.net/Thread-metal-...?pid=16487
20-12-2012, 04:43 PM
can i get some info like its diagramatic working , circuit diagram about VK metal detector
09-07-2013, 02:33 PM
How the metal detectors work?
The operation of metal detectors is based on the principles of electromagnetic induction. It generates a rapidly changing magnetic field by running the alternating current though coil, which will generate eddy currents inside the metal objects. Thereby, the eddy currents will create a new magnetic field that affects the original one, and then the metal detectors will utter a high-pitched tone. The accuracy and reliability of the metal detectors depend on the stability of frequency of electromagnetic launchers. Generally, the frequency is between 80 to 800 KHz. The lower the frequency, the better detection for iron objects. Similarly, the higher the frequency, the better detection for high carbon steel objects. The sensitivity of the metal detectors decreases with the expanding detecting range. Moreover, the induction signal depends on the metal particle size and conductivity. What is the application of metal detectors? According to the application purpose of metal detectors, it can be classified into three types: all-metal detectors, iron metal detectors, aluminum foil metal detectors. The all-metal detectors are able to detect all kinds of metal impurity of different metal materials. They enjoy wide popularity around the world, which gain the highest market share. The all-metal detectors can be used widely in food detecting. They are specially used in detecting the metal impurity in meat, beverage, fruits, vegetables, dairy products, food additives, and health care products and so on. Besides, they can be used to detect the metal impurity in chemical raw materials, rubber, plastics, textile, leather, chemical fiber and toys, etc. Moreover, all-metal detectors can also applied in the areas of medicine, biological, cosmetics, packaging and paper. Next are the iron metal detectors, which is specially used for iron detecting. They are mainly applied in clothing, textile field and other sewing products industry. They are used for detecting the broken needle left over the products during the production. The last one is the aluminum foil metal detectors. As their names indicate, they are used to detect the aluminum foil. The medicine packaging bags and the food packages are mainly made in aluminum foil, which determines the aluminum foil metal detectors are mainly applied in the medicine and food packaging field. More information about metal detectors, please visit detectorall.
09-04-2015, 04:27 PM
557 metal detector circuit nd working
10-04-2015, 11:12 AM
To get full information or details of metal detector please have a look on the pages
https://seminarproject.net/Thread-metal-...?pid=16487 if you again feel trouble on metal detector please reply in that page and ask specific fields in metal detector
08-02-2017, 05:35 PM
read read http://seminarsprojects.in/t-mini-projec...#pid200076 for vk 557 metal detector circuit and working
09-02-2017, 11:21 AM
The circuit described here is that of a metal detector. The operation of the circuit is based on the superheterodyne principle that is commonly used in superheter receivers. The circuit uses two RF oscillators. The frequencies of both oscillators are set at 5.5 MHz. The first RF oscillator comprises the transistor T1 (BF 494) and a 5.5MHz ceramic filter commonly used in the IF TV sound section. The second oscillator is a Colpitt oscillator made with the aid of transistor T3 (BF494) and inductor L1 (whose construction details follow) deflected by capacitor capacitor VC1. These two oscillators? Frequencies (eg, Fx and Fy) are mixed in the mixer transistor T2 (another BF 494) and the difference or beat frequency (Fx-Fy) output of the manifold of the transistor T2 is connected to the detection step comprising the Diodes D1 and D2 79). The output is a pulsating DC that is passed through a low pass filter made with the help of a resistor of 10k R12 and two capacitors of 15nF C6 and C10. The AF amplifier IC1 (2822M) is then passed through the VR1 volume control and the output is fed to an 8 ohm / 1W speaker. The L1 inductor can be constructed using 15 turns of 25SWG wire in a 10 cm (4 inch) diameter air core former and then cemented with insulating varnish. For correct operation of the circuit it is critical that the frequencies of both oscillators be equal to obtain zero beat in the absence of any metal in the vicinity of the circuit. The alignment of the oscillator 2 (to match the oscillator frequency 1) can be done with the help of trimmer capacitor VC1. When the two frequencies are equal, the beat frequency is zero, ie beat friction = Fx-Fy = 0, and therefore there is no sound from the speaker. When the search coil L1 passes over metal, the metal changes its inductance, thereby changing the frequency of the second oscillator. So now Fx-Fy is not zero and the speaker sounds. This way you can detect the presence of metal.
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