Metal Detector Circuit Diagram Using Transistor

There are many metal detector circuits or kits are available to built but mostly are very complicated but the circuit shown here can be built easily and can detect a metal object from 2 to 3 inches away.

Metal detector circuit diagram using transistor.

The detector has a current draw of approximately 9 ma at 18 vdc. The unit is powered by two 9v batteries in series. The circuit can sense a soda can at a depth of six inches and metal pipes at an even greater distance. This is just a colpitts oscillator working in the medium band frequency with a radio to the same frequency.

The above circuit diagram is of a low cost metal detector using a single bc548 transistor and an old radio. The circuit is claimed to be tested but the difficult part in building this circuit is with winding the tapped coil. The following image shows the circuit diagram for the metal detector circuit. Here is a simple metal detector circuit using a ca3140 ic.

1 x 2n2222a npn transistor. 1 x tda0161 proximity detector ic. As a result the batteries should last a long time. This metal detector sensor project is easy to make and is an application of colpitts oscillator.

Four transistor metal detector schematic. Circuit diagram working explanation.