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Metal Detector circuit with TDA2822
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Here is a simple metal detector with TDA2822 and few NPN transistors. There is a small arrow connected from the Emitter of the T3 to the 10n Capacitor C4. That arrow is simply indicating signal flow as right to left in that particular wire, which is different from the remaining circuit's left to right. ..
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Sensitive Geomagnetic Sensor circuit
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This is a rather sensitive circuit which will detect minute variations of a magnetic field, particularly the Earth magnetic field. The principle is based on an audio beat tone generated by two identical oscillators. These must be built in the same manner with the same type of components. In this way we minimize influence from temperature and voltage variations. The two oscillators, called probes, are housed in plastic boxes padded, on the inside, with copper wires terminated in one point only and running parallel to the ferrite rod. This rod, together with the coil was removed from an old Medium Wave radio and a small and powerful magnet was glued on one side...
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Geomagnetic Field Detector circuit
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This basic oscillator will detect the Earth magnetic field. The ferrite rod and coil are taken from an old Medium Wave receiver and a small magnet is glued at one end. Tune to a medium wave commercial station until you hear a beat note. Any movement of the ferrite rod will produce an audible note that depends on the prevailing Earth magnetic field. Screening is essential. Use a plastic box padded, on the inside, with copper wires running parallel to the rod and grounded in one place only. A small hole is made in the box in order to adjust the trimmer capacitor with a plastic screwdriver. An American equivalent to the BC337 could be the 2N2369A but I did not try it out...
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Small Metal Detector II
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A Simple design based on a CS209A IC that can give surprising results and draws very little current from a 9 volt battery. It worked good on the Bench, But not so good outside for general metal detecting. But Definately a good design for detecting studs in a wall, with the right coil! This particular circuit was built so it can be used with an
LED and Buzzer or just the LED or just the Buzzer. Battery voltage can be up to 20 volts, but it doesn't add
to the sensitivity. In Addition, Changes to the Potentiometer value can be made, adding a smaller pot in series to make a more sensitive trip point.
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Simple Metal Detector DIY
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LED 1 will light and the buzzer turns on when the coil is changing inductance. The setup is easy, VR1 is adjusted ( away from any metal objects ) so that LED 1 will light and the buzzor sounds on, and then VR1 will be trimmed until led and buzzer are off...
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Metal detector with CS209A
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A single chip metal detecor with a range of a few inches. This is useful for decting nails or screws in walls and floors, or for locating buried mains cable. The heart of the circuit is a single IC the CS209A made by Cherry Semiconductor. The detector, is a single 100uH choke. The IC has an integral oscillatorm the choke forms part of an external LC circuit, its inductance being altered by the proximity of metal objects. It is the change in oscillation that is amplified and demodulated. Led 1 will light and the buzzer will sound when the choke change sinductance. Set up is easy, VR1 is adjusted with the cjoke away from any metal source so that the LED lights and buzzer sounds. The control is backed off so that the LED goes out and buzzer stops. Now when the choke comes into contact with any metal object that alters its inductance, LED 1 and the buzzer will activate...
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Metal detector with 555
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This circuit detects metal and also magnets. When a magnet is brought close to the 10mH choke, the output frequency changes. ..
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| Clicks: 11466 | Votes: 0 | Comments: 0 | Rating: 0 | Rank: 0
Metal Detector with CS209A
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A single chip metal detecor with a range of a few inches. This is useful for decting nails or screws in walls and floors, or for locating buried mains cable. The heart of the circuit is a single IC the CS209A made by Cherry Semiconductor. The detector, is a single 100uH choke. The IC has an integral oscillatorm the choke forms part of an external LC circuit, its inductance being altered by the proximity of metal objects. It is the change in oscillation that is amplified and demodulated. Led 1 will light and the buzzer will sound when the choke change sinductance. Set up is easy, VR1 is adjusted with the cjoke away from any metal source so that the LED lights and buzzer sounds...
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Beat Balance Metal Detector
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Various embodiments of the BB metal detector have been published, and it has been widely described in the press as a new genre. Instead of using a search and a reference oscillator as with BFO, or Tx and Rx coils as with IB, it uses two transmitters or search oscillators with IB-style coil overlap. The frequencies of the two oscillators are then mixed in similar fashion to BFO, to produce an audible heterodyne...
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Coil Coupled Metal Detector
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A Coil Coupled Operation Metal Detector made from readily obtainable components and using an ordinary medium receiver as a detector. The metal detector shown here may well represent a new genre. At any rate, after some exposure, it is regarded as such by those who have seen it. It is based on a standard transformer coupled oscillator (TCO) - hence the name Coil Coupled Operation (CCO) Metal Detector. Although requiring a BFO (in this case provided by a Medium Wave radio), it differs from a typical BFO detector in that its performance far outstrips that of BFO. Also, unlike BFO, it is dependent on the balance of two coils to boost sensitivity...
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Metal Detector
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The circuit described here is that of a metal detector. The opera- tion of the circuit is based on superheterodyning principle which is commonly used in superhet receivers. The circuit utilises two RF oscillators. The frequencies of both oscillators are fixed at 5.5 MHz. The first RF oscillator comprises transistor T1 (BF 494) and a 5.5MHz ceramic filter commonly used in TV sound-IF section. The second oscillator is a Colpitt’s oscillator realised with the help of transistor T3 (BF494) and inductor L1 (whose construction details follow) shunted by trimmer capacitor VC1. These two oscillators’ frequencies (say Fx and Fy) are mixed in the mixer transistor T2 (another BF 494) and the difference or the beat frequency (Fx-Fy) output from collector of transistor T2 is connected to detector stage comprising diodes D1 and D2 (both OA 79). ..
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Metal detector circuit with CS209A
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This metal detector it's based on the CS209A made by Cherry Semiconductor.The CS209A its a bipolar monolithic integrated circuit for use in metal detection/proximity sensing applications.The CS209A metal detector IC contains two on-chip current regulators, oscillator and low-level feedback circuitry, peak detection/demodulation circuit, a comparator and two complementary output stages.The oscillator, along with an external LC network, provides controlled oscillations where amplitude is highly dependent on the Q of the LC tank. The peak demodulator senses the negative portion of the oscillator envelop and provides a demodulated waveform as input to the comparator. The comparator sets the states of the complementary outputs by comparing the input from the demodulator to an internal reference...
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Metal detector using 555
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A very simple metal detector electronic project can be designed using a simple 555 timer integrated circuit . As you can see in the schematic circuit , this electronic project requires few external electronic parts .
This circuit detects metal and also magnets. When a magnet is brought close to the 10mH choke, the output frequency changes.
This metal detector project can be powered from a power supply that can provide an output DC voltage between 6 an 12 volt .
If a metal is closer to the L1 coil , will produce a change of output oscillation frequency, that will generate a sound in the 8 ohms speaker ...
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Metal detector circuit with TDA0161
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These metal detector circuit diagram is based on the TDA0161 monolithic integrated circuit , designed for metallic body detection by detecting the variations in high frequency Eddy current losses. For detecting metals , TDA0161 require an external LC tuned circuit .
Output signal is determined by supply current changes. Independent of supply voltage, this current is high or low according to the presence or the absence of a close metallic object. This metal detector circuit use two LEDs , which offer an visual indication of presence or absence at a metals ,around the coil . To adjust the circuit you need to make sure there is no metal near the coil and then set the fine adjustment to a "Mid position". After that you need to adjust the course adjustment to turn on the LED and , adjust the fine adjustment to turn off the LED...
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Metal detector circuit with TDA2822
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The metal detector circuit is shown here that the limits represent the sake of simplicity for a metal detector, but the design works remarkably well. It only uses 40,106 Hex Schmitt inverter IC, a capacitor and a search coil and of course batteries. An advantage of IC1b Pin 4 is to be connected to a medium-wave radio antenna, or it should be wrapped around the radio. It can also be used as a hand-held metal detectors...
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