VINTIK-PI V1 metal detector

It is designed to search for larger metal objects at a deep depth. Today, in the article we will examine the “VINTIK-PI Version 1” pulse Induction  metal detector based on three ICs, designed to search for small metal objects. It is more complicated than the original version. The previous one, especially its setting for maximum sensitivity, but the circuit does not contain any programmable ICs, and there are no expensive and scarce electronic components in it. Its sensitivity is several times better than the previous one.

Metal Detector Parameters
Power – 9-12 volts
Current consumption – 30-42 mA
Alarm – light, sound
Sensitivity – telephone microphone (45 mm) – 25 cm, gold ring up to 17 cm

Schematic diagram of  metal detector “VINTIK-PI” (Ver.1)

(A modified version of the metal detector at the end of the article.)

Search coil

Coil L1 (250μH) is wound on a mandrel of 180 – 200 mm and contains 27 turns of PELSHO wire in lacquer and silk insulation with a diameter of 0.3 – 0.8 mm. The wire can be taken from transformers, chokes, deflecting systems or demagnetization loops of any  color TV. The coil can be wound on a round mandrel, such as a bucket or pan. Then remove from the mandrel and wrap several layers of electrical tape. For the manufacture of the coil, you can use a plastic cover from a bucket or hoops for embroidery, in which the wire fits very well.

The coil frame must NOT contain metal! The coil itself in this type of metal detector is also NOT wrapped with foil!

The wire connecting the coil and the board should be thick and preferably shielded, and also not have connections and connectors. In the impulse, the current reaches high values ​​and all of the above affects the sensitivity of the device.

The multimeter can measure voltages (V) at the ICs terminals (without the presence of metal in the coil field / with the presence of metal) (power supply of the metal detector is + 12V):

IC1 (NE555)

  1. 0v
  2. 6.3v
  3. 10.4v
  4. 12.0v
  5. 8v
  6. 6.3v
  7. 6.3v
  8. 12v

IC2 (TL074)

  1. 5.3V
  2. 5.3V
  3. 5.3V
  4. 12V
  5. 0 / 4.1V
  6. 0.8 / 4.3V
  7. 0.8 / 4.3V
  8. 0.1 / 4.3V
  9. 4 / 3.6V
  10. 3.7V
  11. 0V
  12. 12V
  13. 11.1V
  14. 4.0 / 3.6

IC3 (NE555)

  1. 0V
  2. 7.1 / 6.3V
  3. 11.5 / 10.1V
  4. 11.6V
  5. 7,8V
  6. 7.1 / 6.3V
  7. 7.1 / 6.3V
  8. 11.6V
Printed circuit board metal detector “VINTIK-PI” Version 1
VINTIK-PI Metal detector
VINTIK-PI Metal detector
Work with the  metal detector VINTIK-PI V1

When you turn on the regulators R14 “Filter” and R16 “Gain” set the threshold of the beginning of the LED. Adjusting for maximum sensitivity: we find a position where clicks are barely audible in the dynamics!
Further, when the metal is presented, the clicks turn into a crash and then the tone of the generator appears.

VINTIK-PI Metal detector

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