This metal detector can be used to detect metallic
objects. Sensing coil is used to detect metals. This coil should be kept near
metallic objects for detection. Sensing coil forms parts of tuned oscillator.
Input of circuit is a weak colpitt’s R.F. range oscillator.
Working:
When coil is brought near a metallic object magnetic
energy is absorbed and oscillator fails to work then transistor Q4 conducts and
buzzer is activated. Use a 9 V battery. After connecting battery, adjust the
4.7K preset till circuit just stop sounding.
Block
Diagram:
Circuit
Diagram:
Component
Part List:
1
1. Resistors
2. Capacitors:
3 3. Diodes:
5. Miscellaneous:
