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Darkness detector Shadow alarm circuit

Darkness detector Shadow alarm circuit

Light sensor circuit Shadow detector A Buzzer beeped and led will glow for a fixed time when a shadow falls on a phototransistor. This is a very sensitive light-sensitive circuit operated using the 741 opamp ic and 555 timers. Here 741 ic is connected as a comparator which compares the voltage at the input. It is able to detect the […]

Infrared Security Alarm Using PhotoTransistor

Infrared Security Alarm Using PhotoTransistor

IR Based High sensitive Door Security Alarm circuit diagram This IR based security Alarm circuit is highly sensitive. Here A Phototransistor L14F1 is used for the detection of IR rays.  555 timer ic is used to provide a pulsed output For Emitting of IR rays at specific Frequency. The first part of the IR Security Alarm circuit including 555 ic […]

IR Based Security Alarm Circuit

IR Based Security Alarm Circuit

Automatic Door Security Alarm System Introduction This is used to any Door or Gate to Detect Any human person or any animal pass across the gate. When Any Crosses the gate then Automatic alarm beeped for some duration and then after automatically stopped. So even any person or gateman or guard is not available at door, no can be entered […]