Sound-to-Beep Circuit using IC CD4049 is a fun project, where we hear whistle which beep for 3 sec; also circuit is good for door alarm, remote control other sound things. Moreover, it has mic for sound, op-amps from CD4049 and transistor for buzzer and it runs on 3V battery. Circuit Working: Parts List: Components Values […]
Alarm Circuits
Simple Dark Sensor Circuit with Buzzer
The Simple Dark Sensor Circuit with Buzzer is an easy project to build because it detects the absence of light and activates a buzzer, moreover, users can apply it in night lights, security systems and alarm circuits. Here, circuit works with LDR, 555 timer and buzzer, as low light makes buzzer ON. Furthermore, this circuit […]
Electromagnetic Telephone Ringer Circuit
Electromagnetic Telephone Ringer Circuit helps us know when call comes and when there is no need connect to phone line. Also, this circuit is useful when there is no access or do not want to touch phone line, as it works by sensing electromagnetic field from ringing signal and then buzzer turns ON; furthermore, the […]
Simple Shock Sensor Alarm Circuit
In this Simple Shock Sensor Alarm Circuit we can feel vibration or shock, which then makes loud sound with piezo buzzer. Also, we can build this circuit easily and use it at home, in cars and in many other places, as it improves security, helps prevent theft, and detects movement. Furthermore, main parts of the […]
Car Reverse Horn with Musical Tone Circuit
Car Reverse Horn with Musical Tone Circuit is easy and fun way to change beep sound to nice tune; its main part is IC UM66 which makes sweet melody. Also, the 7805 IC reduces the car battery voltage to 5V; additional components support the circuit and help it operate reliably and efficiently. Furthermore, it is […]
Super Sensitive Intruder Alarm Circuit
This article for Super Sensitive Intruder Alarm Circuit talks about very simple but strong intruder alarm circuit, also it is very sensitive. Furthermore, this circuit is useful for security and it can detect very small Interference. This circuit uses IC 741 op-amp and IC 555 timer to work and it also use LDR (light sensor) […]