Security is a primary concern of offices, homes, and other workplaces. For this reason, there is an assortment of security alarms accessible in the market which utilizes different sorts of innovations for interloper locations like infrared sensors, motion detector sensors, ultrasonic sensors, laser sensors, and so on.
We have additionally briefed you on some detailed security alarms in our previous article like PIR sensor-based motion detectors, intruder alarm circuits, and so forth.
In this circuit, we are going to assemble a laser security alarm that utilizes a laser light and a laser light detector circuit. It gets actuated when somebody crosses it, and the laser light gets interrupted.
Hardware Component
The following components are required to make Laser Security Alarm Circuit
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | IC | LM358 | 1 |
| 2. | Potentiometer | 10K | 1 |
| 3. | IC | NE555 Timer | 1 |
| 4. | Capacitor | 220uF | 1 |
| 5. | LDR | – | 1 |
| 6. | Breadboard | – | 1 |
| 7. | Battery | 9V | 1 |
| 8. | LED | – | 1 |
| 9. | Resistor | 150 ohm, 10K | 1, 1 |
| 10. | Laser Light | – | 1 |
NE555 IC Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of NE555 IC
LM358 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of LM358
Laser Security Alarm Circuit
Working Explanation
Meanwhile, in this laser security alarm circuit, we have utilized the LM358 Dual Comparator IC for contrasting voltages originating from LDR. The comparator is arranged as a Non-inverting mode and one 10K potentiometer is associated with its non-inverting terminal. An LDR is utilized for recognizing light or laser light concerning ground through a 10K resistor.
Also, the midpoint of LDR and resistor is legitimately associated with the inverting terminal of the comparator. A red LED is associated with the yield pin of the comparator for demonstrating interloper recognition. A mono-stable multi-vibrator is additionally utilized for actuating buzzer and LED for a specific timeframe. Also, a 9-volt battery utilizes here for powering the circuit.
Applications and Uses
Laser Security System utilizes safety lockers in our homes, where even if the locker’s code is hacked, it acts as an additional layer of security. Apart from security systems, this laser-based alarm can also be used to check if pets or babies crossed a certain boundary.
