door alarm system schematic
The circuit operates on the principle of capacitive sensing, where the touch on the door handle is detected by a capacitive touch sensor. The sensor is connected to a microcontroller or a dedicated touch sensing IC that interprets the capacitive change caused by the human touch. Upon detection, the microcontroller activates a piezo buzzer and an LED indicator.
The schematic includes a power supply circuit that provides the necessary voltage to the microcontroller and the output devices. Typically, a 5V DC power supply is used, which can be derived from batteries or an AC-DC adapter. The touch sensor is connected to one of the GPIO (General Purpose Input/Output) pins of the microcontroller.
When the door handle is touched, the microcontroller receives a signal from the touch sensor, triggering the output. The piezo buzzer emits a sound, while the LED lights up, providing both auditory and visual indications of the alert. The duration of the alarm can be programmed based on the desired response time.
To ensure the circuit can be reset, a manual switch is included, allowing the user to turn off the alarm after the alert has been acknowledged. Additionally, the circuit may incorporate a delay mechanism to prevent false alarms due to environmental factors, such as wind or rain.
Overall, this circuit provides a practical solution for alerting homeowners to potential intrusions, enhancing security through simple yet effective electronic design.This circuit Schematics a beep and/or illuminates a LED when someone touches the door-handle from outside, alarm will sound until the circuit will be switched-off.. 🔗 External reference
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