How to make a simple metal detector
Today there are people who are searching for metal in the vastness of our homeland. They thus earn a living. Some of them hunt for rare things, doing collectibles.
The main tool in their activity is a metal detector. It can be purchased on the market, but a good device is not cheap. Those who are just beginning to search work, it is better to make the device yourself, and in the future, if everything goes as planned, you can think about acquiring a professional metal detector.
From materials for crafts you will need: a timer chip (555); 2.2 uF capacitors (2 pieces); 9 volt battery; buzzer ("tweeter"); wood glue; switch; insulating tape; resistor (47 kOhm); the cable that connects the battery; printed circuit board; wires for connections; 0.2 mm copper wire (100 meters); cardboard.
Of the tools you will need: pliers; soldering iron; tweezers; knife; compass; hot glue; pencil; ruler.
They start from the manufacture of an air coil 9 cm wide. Its base is made of cardboard, winding is carried out with a varnished copper wire, the cross-sectional diameter of which is 0.2 mm. The number of turns that need to be wound on a coil is 260. The ends of the wire are cleaned before soldering and tinning. After the assembled coil is tested using a breadboard.
Then proceed to the assembly of the printed circuit board. Occupation for beginners may seem difficult, but with the acquisition of skills everything will happen quite quickly.
After they begin to make the handle for the metal detector out of cardboard. Three pieces are cut out, holes are made, in which then a switch, batteries are placed. Pieces of cardboard are glued with wood glue and left to dry for half a day. At the end, near the switch, make a hole that will be needed for the passage of wires. The end of this cycle of work is gluing to the handle of the coil - use hot glue.
Having prepared all the components, they begin assembling the metal detector. They install a switch on the handle, insert a battery into it, and attach a printed circuit board. They use hot glue. Next, connect the components mounted on the handle and begin testing the metal detector.
The described craft is not complicated and everyone can assemble it - a beginner may encounter some problems. However, the resulting metal detector can only be used at a small distance and is better indoors. As practice has shown, when working on the street there are failures in the operation of its electronic part. This device can be considered as the initial stage before the manufacture of more complex and reliable devices that will work seamlessly in any conditions.