Simple metal detector

I can say without a doubt that this is the simplest metal detector I have ever seen. It is based on just one TDA0161 chip. You won't need to program anything - just assemble it and that's it. Another great difference is that it does not make any sounds during operation, unlike a metal detector based on the NE555 chip, which initially beeps unpleasantly and you have to guess the metal found by its tone.

In this circuit, the buzzer starts beeping only when it detects metal. The TDA0161 chip is a specialized industrial version for induction sensors. And metal detectors for production are mainly built on it, giving a signal when metal approaches the induction sensor.

You can purchase such a microcircuit at - TDA0161 aliexpress.com

It is not expensive and is quite accessible to everyone.

Here is a diagram of a simple metal detector

Metal detector characteristics

• Microcircuit power supply voltage: from 3.5 to 15V
• Generator frequency: 8-10 kHz
• Current consumption: 8-12 mA in alarm mode. In search state approximately 1 mA.
• Operating temperature: -55 to +100 degrees Celsius

The metal detector is not only very economical, but also very unpretentious.

An old cell phone battery works well for power supply.

Coil: 140-150 turns. The diameter of the coil is 5-6 cm. Can be converted to a coil of larger diameter.

The sensitivity will depend directly on the size of the search coil.

In the scheme I use both light and sound signaling. You can choose one if you want. Buzzer with internal generator.

Thanks to this simple design, you can make a pocket metal detector or a large metal detector, depending on what you need more.

After assembly, the metal detector works immediately and does not require any adjustments, except for setting the response threshold with a variable resistor. Well, this is standard procedure for a metal detector.

So, friends, collect the things you need and, as they say, they will come in handy around the house. For example, to search for electrical wiring in a wall, even nails in a log...

Watch a video of the metal detector in action