Biscuit Line Conveyor Metal Detector

The principle of it is that three coils which are a central transmitting coil and two equivalent receiving coils are installed in a probe, and the oscillator emits a high-frequency magnetic field through the central transmitting coil connecting with the two receiving coils, but the polarity is opposite.Metal detectors work on the principle of transmitting a magnetic field and analyzing a return signal from the target and environment. The transmitted magnetic field varies in time, usually at rates of fairly high-pitched audio signals.Illustrates: A simple diode detector circuit. A blocking capacitor separates the applied DC bias from the input signal; a inductive choke separates the DC supply from the RF supply. The diode is used to peak detect, the capacitor holds the charge, and the resistor sets the bandwidth of the detector.