Very simple metal detector
Without a doubt, I can say that this is the simplest metal detector of all that I have seen. It is based on just one TDA0161 microchip. You won’t need to program anything – just assemble it, and that’s it. Another significant difference is that it doesn’t make any sounds during operation, unlike a metal detector with the NE555 microchip, which initially emits an unpleasant beep, and you have to guess the found metal by its tone.
In this circuit, the buzzer only starts beeping when it detects metal. The TDA0161 microchip is a specialized industrial variant designed for induction sensors. It is commonly used in metal detectors for manufacturing, providing a signal when metal approaches the induction sensor.
You can purchase such a microchip on aliexpress.com – TDA0161. It is reasonably priced and readily available to everyone.
Here is the diagram of a simple metal detector.
Metal Detector Specifications:
- Chip power supply voltage: 3.5 to 15V
- Generator frequency: 8-10 kHz
- Current consumption: 8-12 mA in alarm mode. In search mode, approximately 1 mA.
- Operating temperature: -55 to +100 degrees Celsius
- The metal detector is not only very economical but also very undemanding.
For power, a battery from an old mobile phone is suitable.
Coil: 140-150 turns. Coil diameter 5-6 cm. It can be modified for a larger diameter coil.
The sensitivity will directly depend on the dimensions of the search coil.
In the circuit, I use both visual and sound alarms. You can choose either one if you prefer. The buzzer has an internal generator.
Thanks to such a straightforward circuit, you can make a pocket-sized metal detector or a larger one, depending on what you need more.
The metal detector works immediately after assembly and does not require additional settings, except for adjusting the triggering threshold with a variable resistor. Well, that’s a standard procedure for a metal detector.
So, friends, gather the necessary materials, and, as they say, it will come in handy in the household. For example, for finding electrical wiring in a wall or even locating nails in a log.
Watch the video of the metal detector in action.
