AIM

To design and build a simple Signal Torch using an LED, resistor, switch, battery, and cardboard enclosure. The torch produces light in dark conditions and can also be used as a signal torch for visibility at night.

OBJECTIVE

This project introduces students to the basics of:

• Simple electrical circuits
• Current flow
• LED polarity
• Role of a resistor
• Switch operation
• Battery connections
• Practical wiring
• Making a functional torch using cardboard
• Creativity in designing useful mini-projects

MATERIALS REQUIRED

CIRCUIT DESIGN CONCEPT

• The Signal Torch uses a simple series circuit.
• The battery supplies electrical energy to the circuit. When the switch is turned ON, the circuit is completed and current flows through the resistor and LED.

Current Flow:

Battery (+) → Switch → Resistor → LED → Battery (–)

• The resistor is connected with the LED to help limit the current through the LED.
• When the switch is OFF, the circuit is open and the LED does not glow.

PROCEDURE

Follow the steps below carefully to assemble the Signal Torch.

Step 1. Prepare the Cardboard

Step 2. Prepare the Bottle Cover

Step 3. Make the Rectangular Torch Body

Step 4. Connect the LED and Resistor

Step 5. Connect the Switch and Battery

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Step 6. Install the Circuit Inside the Box

Step 7. Attach the Front Cover

Step 8. Testing the Signal Torch

CIRCUIT DIAGRAM

Figure 1. Circuit Diagram of the Signal Torch

WORKING PRINCIPLE

The Signal Torch works by using a closed electrical circuit. When the switch is turned ON, the circuit is completed.

Electrical current flows from the positive terminal of the battery through the switch, resistor, and LED, and returns to the negative terminal of the battery.

The LED converts electrical energy into light energy, producing illumination. When the switch is turned OFF, the circuit becomes open and current stops flowing, so the LED turns OFF.

This project demonstrates:

• Current flow
• Open and closed circuits
• Switch operation
• LED polarity
• Current limiting using a resistor
• Conversion of electrical energy into light energy

FINAL RESULT

A functional Signal Torch is created using a cardboard body, LED, resistor, switch, battery, wires, and a transparent plastic bottle cover.

When the switch is turned ON, the LED glows and provides light. The torch can also be used as a simple signalling device in dark conditions.

SAMPLE OUTPUT

(i) LED OFF – Torch OFF

Switch is OFF → Circuit is open → LED does not glow.

Sample Output – LED OFF / Torch OFF

(ii) LED ON – Torch ON

Switch is ON → Circuit is complete → LED glows.

Sample Output – LED ON / Torch ON

🎥 MAKER’S LAB VIDEO

ADDITIONAL NOTES

• Always disconnect the battery when the torch is not being used.
• Tape exposed wire joints to reduce the chance of short circuits.
• Handle scissors, cutters, and other sharp tools carefully.
• Ask an adult for help when cutting the plastic bottle or cardboard.
• Do not connect the battery terminals directly together.
• Make sure the LED, resistor, switch, and battery connections are secure.

SAFETY

CREATIVITY EXTENSION

LEARNING OUTCOME

After completing this project, students will be able to:

• Identify the basic components of a simple circuit.
• Explain how a switch controls current flow.
• Identify the positive and negative terminals of an LED.
• Understand the purpose of a resistor.
• Connect an LED circuit to a battery.
• Understand how electrical energy is converted into light energy.
• Build a useful functional model using simple materials.