• UNIQUE FEATURES• OF• PIR MOTION SENSORS

INTRODUCTION

They use built-in amplifier to detect motion

The IR module is specifically used to detect IR radiation (body heat) from the human body

They can also detect other things that generate IR radiation

INTERNAL COMPONENTS

A built-in amplifier to convert IR radiation to voltage

A comparator for converting output to digital form

A stabilized power supply unit to supply power to the circuit

A quad-type pyroelectric element to detect movement within its range

DETECTION OF MOVEMENT

The quad-type pyroelectric element has 4 similar receptors The sensor can pick up even the

smallest movements within the receptor’s range

This makes PIR motion sensors more accurate and effective

WORKING PRINCIPLES

IR motion sensors detect radiation instead of emitting them

The inverting input becomes low when the sensor detects IR radiation

Then the comparator’s output increases and lights up the LED

3 different resistors in the IC transfer current to all internal components

TYPES OF IR SENSORSIR sensors are of different types depending on their usage

Temperature sensors detect temperature

PIR sensors are used for home/commercial

security

Ultrasonic sensors can measure

distance between two points

FOCUSING MECHANISM IN IR SENSORS

OR

PIR motion sensors use

LENS MIRROR

The main task of lenses/mirrors is to focus light onto the

sensor

Mirrors have slightly more range

than lenses

HOW TO AVOID FALSE DETECTIONS

Avoid placing them on the wall directly facing

the window

Avoid installing PIR motion detectors near HVAC vents that blow

cold/hot airInstall them high up on the wall to avoid being triggered by toddlers and pets

THANK YOU