- Laser Security Alarm
- Earthquake Detector
Laser Security Alarm - A laser-based security system is a type of security alarm that uses laser light and a light sensor. A security system protects our homes, offices, banks, lockers etc. from intrusion and unauthorized access. One of the main components of the security system circuit is LDR or Light Dependent Resistors. It detects light and changes its resistance to send a signal to buzzer and LED. When light hits the LDR, its resistance is very low, but when it’s in the dark or light is interrupted its resistance is very high. The LDR is used in combination with the laser to form the light sensor and source.
Earthquake Detector - An Earthquake Detector helps to alarm human beings from an upcoming earthquake so that we can take some precautionary action to prevent both human lives and extensive damage to property. When shake the detector to simulate an earthquake, the copper wire touches the screw eye to form a complete electric circuit, a complete loop with electricity flowing the way it is supposed to flow: from the battery, to the component (buzzer and LED), and back to the battery again.