Theory
5. Interfacing with Sensors ✨
Light controlled DC motor
🔍 Introduction:
💡🔧 The LDR is a component that changes its resistance based on the amount of light it receives. When the LDR is exposed to light, its resistance decreases, allowing more current to flow through the circuit. This causes the motor to spin faster.
🌑➡️ When the LDR is covered and there is less light, its resistance increases, limiting the current flow and causing the motor to slow down or stop.
🛠 Materials:
🌞 LDR (Light Dependent Resistor)
🔄 DC motor
🔋 Battery (9V)
🔗 Jumper wires
📋 Instructions:
🔌 1. Connect the positive terminal of the battery to the positive terminal of the DC motor using a jumper wire.
➖ 2. Connect the negative terminal of the battery to one of the pins on the LDR using another jumper wire.
➕➖ 3. Connect the other pin of the LDR to the negative terminal of the DC motor using a third jumper wire.
🖐🌑 4. Cover the LDR with your hand or an object to block the light and observe the motor’s behavior.
🤲🌞 5. Remove the obstruction and observe the motor’s behavior again.
🔄🌞🌑 6. Try covering and uncovering the LDR repeatedly to see how the motor reacts.
Through this experiment, you can observe how light affects the LDR and how the motor’s speed changes in response to the resistance of the LDR. This is a simple introduction to the concept of light sensing and its practical applications in circuits.
https://www.tinkercad.com/things/bRtr3sM6HVJ-dc-motor
🔆 Photo Resistor: A photo-sensitive resistor whose resistance changes with light intensity. This variation in resistance alters the current in the circuit, thereby affecting the DC motor’s speed.
Tilt Sensor:
Introduction:
- 🔄 The tilt sensor adjusts its electrical properties based on orientation.
- ⚡️ It controls electric flow in the circuit.
- 📐 When tilted, it either permits or blocks electricity, toggling the LED.
- 🧪 This experiment elucidates tilt sensor functionality and its role in circuit control.
- 📱 Tilt sensors find applications in gaming controllers and smartphones.
- 🌐 They showcase the extensive potential of sensors in technology.
🛠 Materials:
📏 Tilt sensor
📐 Resistor (220 ohms)
💡 LED (any color)
🔋 Battery
🔗 Jumper wires
📋 Instructions:
🔌 1. Connect one leg of the tilt sensor to the positive terminal of the battery using a jumper wire.
🔗 2. Connect the other leg of the tilt sensor to one leg of the resistor.
💡🔗 3. Connect the other leg of the resistor to the positive leg of the LED.
➖💡 4. Connect the negative leg of the LED to the negative terminal of the battery using another jumper wire.
🔄 5. Tilt the sensor and observe the behavior of the LED.
🔄👀 6. Try tilting the sensor in different directions to see how the LED behaves.
https://www.tinkercad.com/things/gRvdg41Bdcv-tilt-sensor
PIR sensor
🔬 Introduction:
- The PIR motion sensor detects changes in infrared radiation emitted by objects in motion within its field of view.
- 🚦 When motion is detected, it triggers the flow of electricity through the circuit, lighting up the LED.
- 🛑 When no motion is detected, the circuit is not completed, and the LED remains off.
🌟 Through this experiment, kids can learn how PIR motion sensors work and their application in devices like security cameras and automatic doors. It’s a fun way to introduce the concept of sensors in electronic devices!
🎒 Materials Needed:
- 🤖 PIR (Passive Infrared) motion sensor
- 🔌 Resistor (220 ohms)
- 💡 LED (any color)
- 🔋 Battery
- 🌈 Jumper wires
📋 Instructions:
- 🔌 Connect one leg of the PIR motion sensor to the positive terminal of the battery using a jumper wire.
- ➕ Connect the other leg of the PIR motion sensor to one leg of the resistor.
- ➡️ Connect the other leg of the resistor to the positive leg of the LED.
- ⬅️ Connect the negative leg of the LED to the negative terminal of the battery using another jumper wire.
- 🔛 Turn on the battery and wait for the motion sensor to calibrate (usually takes a few seconds).
- 🏃♂️ Once calibrated, move in front of the motion sensor and observe the behavior of the LED.
- 🕵️♀️ Try moving at different distances and angles to see how the LED behaves.
https://www.tinkercad.com/things/g9x89ldWRaW-pir-sensor
PIR sensors allow you to sense motion, almost always used to detect whether a human has moved in or out of the sensors range