Metal sensor detector circuit schematic with TDA2822

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. As you can see what metal a good selection of beat-frequency operation (BFO), up to 90 mm for a bottle-top. In fact, for the ultimate in simplicity, the capacitor C1 is omitted. In this way, the author reaches is astonishing, 150mm range for the bottle top. But with the frequency then to more than 4 MHz, the instability is a major problem.
 metal detector circuit
 As shown in the circuit, oscillates at 230kHz. You can also experiment with the frequency by changing the value of C1. Faraday shield can be added to reduce ground-effect and capacitive coupling, and this is connected to 0V.
Since the inductance is resistance to rapid change in voltage, the charging of fees C1 delayed a bit like the logical level IC1a 2-pole change. This requires a rapid oscillations, which is repealed by an AM radio. Any change in the inductance in the search coil (by the presence of metal) to a change in the oscillator frequency. Although 230kHz is out of reach for the medium-wave band, an AM radio will significantly increase this frequency harmonics.
Metal detector calibration
This makes the search coil L1 is much room for error and is not far from conclusive. The author uses seventy turns 30 s.w.g. (0,315 mm) copper wire on a former 120mm diameter.
The metal detector, set up by the AM radio to pick up a whistle. Not all of these harmonic functions well, and are best suited to. The presence of metal will significantly change the sound of the whistle.
* Metal Detector FAQ *
This is not an industry or security metal detector and is not even near loma or ERIEZ metal detection system. It’s just a notebook, but not hand-metal detector.

Source  http://www.free-circuit.com
Share this article :

+ comments + 3 comments

6 April 2013 at 16:55

Buy Godrej Door Frame Metal Detector in India. Get best and cheap prices with installation guide. Know the features, application, technical specification, certificates and product comparison for Godrej Door Frame Metal Detector

Door Frame Metal Detector|| Metal Detectors

1 April 2015 at 17:56

The circuit explain is good thanks for sharing this blogs Metal Detector Dubai|Gold Detector Dubai
Gold Detector

6 August 2018 at 12:10

Does this divice can detect metal object a few inches away.

Post a Comment

 
Support : Creating Website | Johny Template | Mas Template
Copyright © 2011. The Circuit - All Rights Reserved
Template Created by Creating Website Published by Mas Template
Proudly powered by Blogger