Simple Thunder Lightning Detector Circuit

This circuit shows you how to build a storm chasers tool a lightning detector!

Lightning makes a special kind of electricity in the sky.

This circuit can sense that electricity and light up or make a sound to warn you when a storm is nearby.

This can give you extra time to get inside before the rain starts.

Circuit Working:

Parts List:

The circuit is designed to emit an audible warning tone through a piezo buzzer or flash an LED upon detecting each discharge.

This allows users to receive advance notice of impending storms enabling them to take necessary precautions.

A key feature of the lightning detector is its capability to be set close to self oscillation optimizing relaxation through the bias resistor values indicated in the circuit diagram.

The oscillator, which is DC coupled, routes feedback through the collector of TR1 to the base of TR2.

The overall loop gain is adjusted with the multiturn preset VR1.

To configure the lightning sensor, adjust preset VR1 for oscillation while monitoring test point TP1 aiming for approximately 7V peak to peak.

Test point TP2 should read +6V DC.

Fine tune VR1 to halt oscillation, and touch the aerial side of C1 with a screwdriver several times.

The alarm should sound for 1 or 2 seconds and then stop.

If it persists make slight adjustments and recheck.

Alternatively, electrostatically charge a plastic ruler and draw it close to the discharge approximately two meters away from the aerial.

Powered by a 9V battery, the circuit consumes about 600µA in standby mode.

With continuous power it can provide a year of uninterrupted monitoring.

During the alarm activation the current increases to 4 mA depending on the low current sounder WD1.

A minimum 3V device is necessary for optimal output producing a real time ‘pinging’ alarm for any electrostatic pulse activity.

Formulas:

There are several formulas you may use to make sure the circuit operates properly and the component values for a thunder lightning detector are correct.

The following are the main formulas along with their uses:

Biasing and Amplification of Transistors

Calculating the Base Resistor:

For a transistor to operate properly, the base resistor RB is essential.

It guarantees that the transistor operates in the active area with the proper bias.

R_B ​=​ V_CC​−V_BE​​ / I_B

where,

• VCC is supply voltage such as 9V
• Base Emitter voltage of the transistor usually 0.7V for BC547 is represented as VBE.
• Base current is IB.

To determine IB​:

I_B​ = ​I_C​​ / h_FE

where,

• IC is desired collector current
• hFE is transistors current gain (hFE) for BC547, this is usually 100.

Resistor and Capacitor for Timing and Filter Capacitors:

The cutoff frequency fc, for a basic resistor capacitor RC filter, may be computed as:

fc ​= 1​ / 2πRC

where,

• Cutoff frequency Hz is equal to fc.
• Resistance Ω represents R
• C equals capacitance F.

Resistor Power Dissipation:

Determine the power dissipation to make sure resistors can withstand the power without overheating:

P = I² × R

where,

• P is for power loss W
• I is the resistors current through value A.
• Resistance value Ω R

Reactance of Capacitors:

Compute the reactance of capacitors XC to learn how they impact the circuit:

X_C​ = 1​ / 2πfC

where,

• C is the capacitive reactance Ω in XC
• f is the signals frequency in Hz
• C equals capacitance F

Power to the buzzer and LEDs:

Make sure the current flowing via LEDs is suitable to prevent damage:

I = ​V_supply − V_LED ​​/ R_LED

where,

• I is the LEDs current throughput A.
• Supply voltage Vsupply is voltage
• VLED The LEDs forward voltage, which is usually 2V.
• RLED is the series resistor Ω in series

You may effectively construct and debug your thunder lightning detector circuit with the aid of these formulae.

Modify component values as needed in accordance with testing and design specifications.

How to Build:

Building the lightning detector circuit involves assembling the components and following the provided instructions.

Gather Components:

• Ensure you have all the necessary components listed above.

Create the Circuit Board:

• Lay out the components on a circuit board, following the circuit diagram provided.
• Connect the components using wires and solder them in place.

Install Transistors TR1 and TR2:

• Insert the transistors into their designated places on the circuit board ensuring proper orientation. Connect the collector of TR1 to the base of TR2.

Connect Preset VR1:

• Connect the multiturn preset VR1 to the circuit setting it according to the circuit diagram.

Add Capacitor C1:

• Connect the capacitor C1 to the circuit.
• The value is not specified, so you may need to choose a suitable capacitor based on the requirements of the circuit.

Integrate the Sounder WD1:

• Connect the low current sounder WD1 to the circuit.
• Ensure that it is connected appropriately to provide the desired alarm function.

Attach Antenna:

• Attach the short length of wire to the designated antenna point on the circuit board.

Power Connection:

• Connect the battery connector to the circuit, providing power from a 9V battery.

Testing:

• Adjust preset VR1 for oscillation while monitoring test points TP1 and TP2 following the provided voltage specifications.
• Fine tune to stop oscillation and test the circuit by touching the aerial side of C1 or using the electrostatic method described.

Final Adjustments:

• Make any necessary adjustments to ensure the circuit operates as intended.

Note:

• Remember to exercise caution when working with electronic components and soldering.
• If you are unfamiliar with electronics or soldering seek assistance from someone experienced and always double check your work to avoid any mistakes or damage to the components.

Conclusion:

To conclude, It is important to note that while these circuits can provide indications of approaching thunderstorms they may not necessarily detect every lightning strike.

The effectiveness of a lightning detector depends on factors such as its sensitivity the quality of the antenna and the surrounding environment.

References:

Lightning detection

Prototyping a RF signal-based lightning warning device using with Internet of Things (IOT) integration