Today, in the tutorial, we will establish an IR Based Security Alarm. The IR defense alarm circuit can detect and stimulate any progression. Warning device. This circuit is advantageous in apartments, financial institutions, stores, and spots where an alert is needed while planning to travel.
This circuit is based on an IR sensor in which the IR beam collapses on a photodetector repeatedly. When the internal and external environments are interrupted, an alarm is enabled by some form of vibration.
Hardware Component
The following components are required to make an IR-based Security Alarm Circuit
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | Buzzer | – | 1 |
| 2. | Capacitor | 10uF | 1 |
| 3. | Variable Resistor | 10k | 1 |
| 4.. | IC | NE555 timer | 1 |
| 5. | IC | LM358 | 1 |
| 6. | Resistor | 10k, 100k, 100 ohm, 220 ohm, 330 ohm | 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
IR-based Security Alarm Circuit
Circuit Operation
In this circuit, we used the LM358-op-amp. There are two voltage comparators in it, and in this circuit, we have used one comparator. The voltage comparator’s non-inverting end (PIN3) is attached to the photodiode, and the inverting end (PIN2) is connected to the 10k voltage regulator. A 555 timer sensor pin is associated with the output power from the voltage comparator (PIN1). In monostable mode here, 555 Timer is set up.
Now that there is some vibration, the fall of IR rays on the Photodiode will be avoided. The voltage at the inverted end of the tension comparator (threshold voltage) will, for a moment, be more potent than the non-inverted end. This produces a LOW output, and indeed the 555 timer PIN 2 is LOW. This activates the 555 timers, and the OUTPUT of 555 timers is Strong and Buzzer for a short period. The beep interval can be improved with a shift in tension value R1 or compressor C1 (RC network in monostable mode of 555 timer IC). If Trigger PIN 2 gets LOW, 555 IC will be activated.
Applications and Uses
The IR security alarm circuit can sense and activate any activity. This circuit is advantageous in apartments, banks, supermarkets, and fields where an alarm is needed while visiting, whereas there was a misjudgment. IR rays stop falling into a photodiode whenever someone moves through this light source.
