Converting the radio into a 30 cm depth metal detector

 Hello my friends

Make a metal detector

The metal detector has excellent depth. It distinguishes minerals and pieces that are abundant

This detector consists of two parts:

 The first section: It consists of a signal oscillator, which is the oscillator used in the reactivator detector, the sufficient detector, which in turn consists of two signal oscillators, so that the first oscillator with the first coil sends an electromagnetic signal with the same strength as the signal of the second oscillator with the second coil, and they merge with the third oscillator, which is called the mixer, then this mixer sends The signal coming to the stacking operations, after which the signal is controlled by means of a variable radio tuner or two variable tuners on the first coil or on the first and second coils.

The second section of this detector:

 The signal receiver consists of the IC555, where the signal comes from the third oscillator (the mixer), which amplifies it and outputs it through the speakers.

How does this detector work?

When the coil passes over a metal, a difference occurs in frequency as a result of this passage, and thus a difference occurs between the frequency of the first coil located close to the ground from the second coil located in the head of the device, or the two coils are close to the surface of the earth, and as a result of this difference, a sound occurs, which is the sum of the difference between the frequency of the two coils.

 Dear brothers, the IC555 is used to enlarge and clean the frequency, and from here we must get to know this IC more by following the topics on our site

General information about the ic555:

The IC555 consists of eight legs, pin No. (1) we connect it with the negative line of the circuit, and pin No. (2) we always connect it with pin No. (6) and pin No. (3) is the frequency output, and pin No. (4) is connected to pin No. ( 8) And they connect together with the circuit positive, pin No. (5) for the timer without connection, as for pin No. (6) for the timer, it has different states according to the type of circuit, and here we explain the following:

 When the timer is intended to enlarge the frequency, this pin is connected directly to the frequency to be enlarged, and no capacitor is connected in this case with pin No. (6).

 When the timer is intended to produce a known frequency, a capacitor is connected to this leg that matches the required frequency.

:As for man number seven for the timer, it has two cases as well

1- In the event that we want the timer to enlarge the frequency, this leg is not completely connected and left as it is.

2- When the purpose of the timer is to produce a specific signal, this leg is connected to a resistance, and this resistance is connected to the positive line of the circuit, and the value of this resistance is proportional to the frequency to be produced.

Man No. (8) of the timer is connected to the circuit positive.

- 2 IC555 metal detectors and 2 transistors

We leave you with the video of the device and then draw the circuit:

:Printing scheme

:circuit diagram

It is preferable that the second coil be as small as a stick of glue and insert instead of the adhesive a piece of iron and fix it inside it and wind a large number of turns on it up to 120 turns until the sound comes out and here begins the role of the device maker to balance the sound by moving the piece of iron inside the coil.