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Alarm Circuits

PIR Sensor Motion Alarm Circuit Transistor and Relay

Last updated on 4 July 2026 by Admin-Lavi Leave a Comment

Nowadays, security is very important that why homes and shops need protection; so to safeguard this motion sensor circuits are useful. The PIR Sensor Motion Alarm Circuit with Transistor and Relay is simple because it uses only a few components, costs very little, and is easy to build. The circuit works using a PIR sensor […]

Filed Under: Alarm Circuits, Automation Circuits, DIY Projects, Security and Protection, Sensors and Detectors, Transistor Circuits

5 To 20 Minutes Alarm Timer Circuit

Last updated on 4 July 2026 by Admin-Lavi Leave a Comment

Time control is very important in our daily life, sometimes we do forget small tasks; so this 5 To 20 Minutes Alarm Timer Circuit helps us remember. This circuit provides an alarm after a preset time by using the popular IC 555 timer. We can select a delay from 5 to 20 minutes by pressing […]

Filed Under: 555 Timer Projects, Alarm Circuits, DIY Projects, Timer Circuits

Simple Infrared Fire Alarm Circuit

Last updated on 1 July 2026 by Admin-Lavi Leave a Comment

This is Simple Infrared Fire Alarm Circuit for beginners, as it use infrared receiver sensor to detect fire heat or flame light. When fire come close sensor output changes and then LED glow and buzzer makes sound; also this circuit is cheap and easy to make. Furthermore, it also uses only few parts like BC547 […]

Filed Under: Alarm Circuits, Mini Projects, Security and Protection, Sensors and Detectors

Laser Light Alarm Circuit using Arduino

Last updated on 1 July 2026 by Admin-Lavi Leave a Comment

This article is for simple Laser Light Alarm Circuit using Arduino. A laser light shines on an LDR and when someone blocks the laser beam, the LDR changes its value and then Arduino reads this change and turns ON the buzzer to make alarm sound. A reset button stops the alarm. Also, the system uses […]

Filed Under: Alarm Circuits, Arduino Projects, LDR Circuits, Security and Protection

Simple PIR Motion Detector Circuit

Last updated on 29 June 2026 by Admin-Lavi Leave a Comment

This simple and easy circuit uses a PIR sensor to detect human motion; when motion happens, PIR output goes high and this high signal turns ON an LED through a resistor. Also, this Simple PIR Motion Detector Circuit is easy to make and works with 12V supply. Circuit Working: Parts List: Components Value Quantity Resistors […]

Filed Under: Alarm Circuits, Automation Circuits, Hobby Circuits, Mini Projects, Security and Protection, Sensors and Detectors

Simple Thermistor Based Fire Alarm Circuit

Last updated on 29 June 2026 by Admin-Lavi Leave a Comment

This Simple Thermistor Based Fire Alarm Circuit is very small, simple and smart, as it uses a thermistor to sense heat fast; when temperature goes high the circuit wakes up and makes loud sound. Here, this circuit uses no microcontroller or complex parts, but it uses only a few components and provides a working fire […]

Filed Under: Alarm Circuits, Heater and Temperature Controllers, Hobby Circuits, Mini Projects, Security and Protection, Sensors and Detectors

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