This project I will explain how we can control a relay remotely using a SIM card and a normal mobile phone, with help of Arduino and a GSM module. The relay can be turned ON or OFF by sending an SMS or by making a phone call to the SIM card placed inside the GSM […]
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AC 220V Over Current Monitor and Cut OFF Circuit
The proposed AC mains 220 V load over current cut off circuit continuously monitors the current flowing through a connected load. If this current increases beyond a certain preset level, the circuit trips the relay and disconnects the load from the AC. Basic Working This 220 V over current cut off circuit is indeed subject […]
ON/OFF Relay Switch Circuit using Reflection Sensor
This 220 V ON/OFF electronic relay switch can be toggled ON/OFF simply by alternately bringing your finger close to the reflection sensor CNY70. About CNY70 CNY70 is an infrared reflecting sensor comprised of an infrared emitting diode and a phototransistor housed in a tiny plastic container. The sensor operates by generating infrared light and sensing […]
Delay OFF Lamp Timer Circuit
This delay off lamp timer circuit will automatically switch OFF a connected lamp after a predetermined time has elapsed. This time delay can be adjusted with a variable resistor or a potentiometer. The circuit is initiated by pressing a push button, which causes the connected lamp to switch ON. The lamp will continue to remain […]
Clap Switch Circuits with Relay ON/OFF: [Tested]
The clap switch circuits explained here will toggle a connected load ON and OFF in response to alternate clap sounds? Here I have explained 4 unique and simple designs which can be selected as per user preference. The article talks about what the title suggests – a clap switch. A small electronic circuit when built […]
Password Controlled AC Mains ON/OFF Switch
In this post I will show how to construct a password based mains ON/OFF switch circuit, which can turn ON and OFF the AC mains supply, only when correct password is entered. This prevents the danger of electrocution of the technician who might be currently working with the high voltage lines and equipment. Password Protection […]





