Motion Detector Alarm Circuit
The motion detector alarm system operates on the principle of infrared (IR) detection, leveraging the HOA1405 module which consists of an IR LED (transmitter) and a phototransistor (receiver). When a person moves within the detection range of 1 meter, the IR light emitted by the LED is interrupted, causing a change in the light received by the phototransistor. This interruption is processed by the alarm circuitry, which triggers an alert signal.
The circuit typically includes a power supply, often a battery or DC power source, to provide the necessary voltage for the IR module. The output from the phototransistor can be connected to a microcontroller or a simple comparator circuit that amplifies the signal and activates an alarm system, such as a buzzer or LED indicator, when motion is detected.
For optimal performance, the IR module should be positioned at an angle that maximizes the coverage area, ensuring that the detection zone is effectively monitored. Additional components may include resistors to limit current through the IR LED, capacitors for noise filtering, and a relay or transistor switch to control higher power devices for the alarm output.
Overall, this motion detector alarm is a compact and efficient solution for security applications, providing reliable detection capabilities in a straightforward design.This motion detector alarm can detect a moving person from a distance of 1 meter. It uses a dual IR Transmitter-Receiver module HOA1405. When the sensor de.. 🔗 External reference
Related Circuits
A string of three series-connected, normally closed switches is connected across the gate of a silicon-controlled rectifier (SCR). When one switch opens, the SCR is triggered through resistor R1, activating an alarm. The alarm is designed to be of...
A while ago I got an email asking for the schematic of a circuit to detect cut phone lines. It didn’t take me long to find this circuit in Electronics Now. When the circuit detects that a phone line...
The post explains a simple 1 watt LED driver circuit using a single 1.5 V penlight cell through the joule thief concept. The coil may be wound over a T13 toroidal ferrite core using 0.2 mm or 0.3 mm...
Short circuits in the tracks, points, or wiring are almost inevitable when building or operating a model railway. Although transformers for model systems must be protected against short circuits by built-in bimetallic switches, the response time of such switches...
The basic application circuit for a thermistor is illustrated. Figure (a) depicts a fundamental temperature measurement circuit with limited accuracy, suitable only for applications that do not require high precision. RT represents a positive temperature coefficient thermistor; as the...
As shown in the figure, the 555 timer, resistors R1, RP1, and capacitor C1 form a controlled audio oscillator. The frequency of the oscillator is given by the formula f = 1.44 / ((R1 + 2 * RP1) *...