A Simple Metal Detector Circuit is a cool electronic device that helps find metal objects nearby.
People use these gadgets for many things like checking security, searching for treasure and in different industries.
In this article we will talk about a simple but powerful metal detector circuit that uses just one chip the CS209A.
This design makes it easy to build and ensures it works really well for detecting metal.
What is awesome is that this circuit can pick up metal items from several inches away.
Also, it runs on a 9V power supply which makes it super handy and efficient for everyone.
Circuit Working:
Parts List:
| Component Type | Specification | Quantity |
|---|---|---|
| Resistors (1/4 watt) | 10k | 1 |
| 220Ω | 1 | |
| 1k | 1 | |
| Potentiometer | 10k | 1 |
| Capacitors | Ceramic 2.2nF | 2 |
| Electrolytic 10µF 25V | 1 | |
| Semiconductors | IC CS209A | 1 |
| LED any 5mm, 20mA | 1 | |
| Other Components | Coil Inductor 100µH | 1 |
| Piezo Buzzer | 1 | |
| ON/OFF Switch | 1 | |
| 9V Battery | 1 |
The LC circuit, which includes the inductor L1 and capacitor C1 acts like a resonant tank circuit that vibrates at a specific frequency.
When a metal object gets close to the inductor L1 it changes the inductance causing the resonant frequency to shift.
The CS209A integrated circuit is made to notice this change and then turns on its output which lights up the LED1 and sounds the piezo buzzer giving both a light and sound alert to show that metal is nearby.
When the metal object is taken away the frequency goes back to normal causing the LED1 and piezo buzzer to turn off.
The Pot VR1 is used to change how sensitive the circuit is.
Formulas with Calculations:
Formulas with calculations mentioned below makes easier to design a Simple Metal Detector Circuit using IC CS209A:
LC Resonant Frequency:
The oscillation frequency of the LC tank circuit is given by:
f = 1 / (2 * π * √(L * C))
where,
- L is 100µH inductor value
- C is 2.2nF capacitor value
Substituting values:
f = 1 / (2 * 3.1416 * √(100 * 10^(-6) * 2.2 * 10^(-9)))
f = 339 kHz
Thus, the circuit operates at around 339 kHz in the absence of metal.
When metal is introduced the frequency shifts triggering detection.
How to Build:
To build a Simple Metal Detector Circuit using IC CS209A follow the below mentioned steps for connections of circuit:
- Gather all the components as mentioned in the above circuit diagram
- Connect pin 1 of IC1 CS209A to one pin of VR1 and second pin of VR1 connect to one end of resistor R1 and other end of R1 to pin 8 of IC1.
- Connect pin 2 of IC1 to one end of L1 inductor through resistor R2 and other end of L1 connect to pin 3 of IC1.
- Connect a capacitor C1 between resistor R2 and L1 inductor.
- Connect pin 4 of IC1 to one end of piezo buzzer and other end of buzzer connect to GND.
- Connect pin 6 of IC1 to GND through capacitor C3.
- Connect pin 7 of IC1 to positive of +9V battery through S1 On/Off switch, connect a positive of capacitor C2 from pin 7 and negative of C2 to GND.
- Connect one end of resistor R3 and LED1 in series between pin 4 and piezo buzzer and other end connect between pin 7 and positive of capacitor C2
Conclusion:
This Simple Metal Detector Circuit using IC CS209A is easy to make and works really well making it perfect for beginners and hobbyists.
The CS209A chip keeps the design small and helps it detect metals reliably.
You can change the values of the inductor and capacitor to adjust how sensitive the circuit is for different uses.