Battery is very important in many electronic systems. However battery voltage drops with time, if voltage becomes too low then battery can get damaged. So low voltage indication is needed. Therefore, this 12V Battery Low Voltage Alarm Circuit helps to protect battery. It gives visual and sound alert and is simple and is with low […]
Alarm Circuits
Low Voltage Alert Circuit for 9V Battery
Battery power is very important in electronic circuits. But many times a battery voltage becomes low without notice. As a result, devices stop working suddenly and therefore, a low voltage alarm is needed. This Low Voltage Alert Circuit for 9V Battery gives warning when a 9V battery goes low. It uses LM339 comparator IC and […]
PIR Sensor Motion Alarm Circuit Transistor and Relay
Nowadays, security is very important that why homes and shops need protection. So to safeguard this motion sensor circuits are useful. PIR Sensor Motion Alarm Circuit Transistor and Relay is simple. It uses very few components and is with low cost and is also is easy to build. The circuit works using a PIR sensor […]
5 To 20 Minutes Alarm Timer Circuit
Time control is very important in out daily life. Sometimes we do forget small tasks. So this 5 To 20 Minutes Alarm Timer Circuit helps us remember. It gives alarm after a fixed time as the circuit uses popular IC 555 timer. Time can be selected from 5 to 20 minutes by just pressing start […]
Simple Infrared Fire Alarm Circuit
This is Simple Infrared Fire Alarm Circuit for beginners. It use infrared receiver sensor to detect fire heat or flame light. When fire come close sensor output changes. Then LED glow and buzzer makes sound. This circuit is cheap and easy to make. It also use only few parts like BC547 transistor, LED, buzzer, IR […]
Laser Light Alarm Circuit using Arduino
This article is for simple Laser Light Alarm Circuit using Arduino. A laser light shines on an LDR. When someone blocks the laser beam, the LDR changes its value. Arduino reads this change and turns ON the buzzer to make alarm sound. A reset button stops the alarm. The system is low cost and easy […]