PIR SENSOR
General Description:
PIR (Passive Infrared) sensors detect infrared radiation emitted by heat sources like people or animals, despite being invisible to humans. Often termed 'motion detectors,' they sense movement by detecting changes in infrared wavelengths. Equipped with a pyroelectric sensor, PIR sensors measure varying levels of infrared radiation emitted by objects. Unlike active sensors, they do not emit energy but only detect it. When motion occurs within the sensor's range, it triggers a positive change; when motion stops, it triggers a negative change, enabling motion detection.
Working Principle:
Passive Infrared sensors do not emit energy into space. Instead, they receive infrared radiation from objects, particularly the human body, to initiate an alarm. Objects with a temperature above absolute zero consistently radiate infrared rays into their surroundings. The human body, with a surface temperature between 27°C and 36°C, emits most of its radiant energy in the wavelength range of 8 μm to 12 μm.
Within the detection area, the PIR sensor's lens captures infrared radiation emitted by the human body, even though clothing focuses it on the pyroelectric sensor. When a human body enters and exits the sensor's view, the pyroelectric sensor detects temperature changes, generating an alarm signal.
Specifications:
- Operating voltage varying from 4.5 V to 20 V
- Output voltage is High/Low (3.3V TTL).
- Can distinguish between object movement and human movement
- Has to operating modes - Repeatable(H) and Non- Repeatable (NH)
- Cover distance of about 120° and 7 meters
- Average current consumption of 0.06 mA
- Operating temperature from -20° to +80° Celsius
- Sensing range extends up to 7 meters
Requirements
| S. No. | Component Name | Values |
|---|---|---|
| 1 | BISS0001 CHIP | |
| 2 | 3V DC Regulator | |
| 3 | Retrigger Setting Jumper | |
| 4 | Pyroelectric Sensor | |
| 5 | Fresnel Lens | |
| 6 | Time Delay Adjust | |
| 7 | Sensitivity Adjust | |
| 8 | Resistors | 10k, 18k, 47k, 1M, 2k, 6.8k, 470k |
| 9 | Capacitors | 47μ, 103, 22μ, 104, 502 |
| 10 | Male Connector | 3 |
Pin configuration:
| S. No. | Pins | Pin Description |
|---|---|---|
| 1 | VCC | The input voltage is +5V for typical applications. Can range from 4.5V- 20V |
| 2 | High/Low Output (Dout) | Digital pulse high (3.3V) when triggered (motion detected) digital low(0V) when idle (no motion detected) |
| 3 | Ground | Connected to the ground of the circuit |
Applications:
- Switch
- Motion sensor
- Thief-guarding system
- Industrial automation
- PIR sensors are used in thermal sensing applications, such as security and motion detection.
- The IR Sensor can be used in IP cameras.
- Used for Alarm systems and other crime-prevention devices.
