Page 70 - Ai Robogenius

maker mission

Laser Security System

Create a laser home security system that triggers an alarm (LED and buzzer) when the laser beam is
broken. This system uses a laser pointer and a mirror to simulate how real security systems use infrared
(IR) sensors to detect motion.
Materials Required:

Laser pointer, cardboard box, mirror 9V battery, LED, buzzer
BC 547 transistor, LDR (Light Dependent Resistor) 2.2K ohm resistor, switch, wires

Pencil, glue, tape, cutter
The steps to create the Laser Security System are:

STEP - 1 Take the cardboard box and set it up as the base for the
system.

STEP - 2 Mount the laser pointer at one corner of the cardboard and
place 3 small mirrors at the other corner of the cardboard.

STEP - 3 Take the 9V battery, LDR, LED, buzzer, BC 547 transistor, 2.2K
ohm resistor and wires.
STEP - 4 Connect the components of the circuit according to the
diagram provided.

STEP - 5 Paste the circuit onto the cardboard and attach a switch to
control when the laser security system is ON or OFF.

STEP - 6 Adjust the mirror so that it reflects off the mirrors and hits
the LDR.

STEP - 7 Turn on the switch and activate the laser. A perimeter is formed by the laser beam, which
creates an invisible security boundary.

When the laser beam is uninterrupted, the system stays inactive with the LED and buzzer off. If the beam is
broken, the LDR detects the light change, activating the transistor to power the LED and buzzer, triggering
the alarm for a security breach.

AI RoboGenius - VII
68