Or consider needing a power outlet socket for mobile phone charger that automatically turns off after a set time to prevent overcharging and extend lifespan of the mobile phone and charger. These scenarios can be made possible with a simple on/off timer that can be easily assembled at home.
This simple on-off timer can control any household electrical device that needs to be switched on or off after a specific duration. It employs inexpensive components wired in an analogue circuit, providing extended timer duration without the complexity of digital ICs or microprocessor programming. Higher loads can be controlled by selecting higher current relays, switches, and wires, or external contactors. EFY lab tested the prototype on a breadboard, as shown in Fig. 1.
Circuit and working Fig. 2 shows the circuit diagram of the simple on/off timer. It is built around transformer X1, bridge rectifier BR1, 12V voltage regulator LM7812 (IC1), dual op-amp LM358 (IC2), transistor BC547 (T1), 12V SPDT relay, one 1N4007 diode (D1), signal diode 1N4148 (D2), two LEDs (LED1, LED2), and a few other components.
This story is from the August 2024 edition of Electronics For You.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber ? Sign In
This story is from the August 2024 edition of Electronics For You.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber? Sign In
STK435 IC-Based STEREO AMPLIFIER
This stereo AF amplifier uses the STK435 IC, a highly popular choice due to its simplicity.
A SEWER DRAIN SHIELD For Smart Cities
Drainage systems are vital for storm water management but often transport pollutants, especially plastics, to rivers and oceans, harming ecosystems.
ESP32 SPEECH FUNCTION: Text To Speech
Speech capability in technology primarily has two dimensions: text to speech (TTS) and speech to text (STT). This device focuses on TTS.
World's Smallest Programable INDUSPHONE DESIGN
This is the second part of designing the world’s smallest phone, where the UI is integrated with the basic functions of the phone.
FLAME-SENSING FIRE ALARM Using An Arduino Nano
Fire safety alarms are crucial in both residential and industrial environments.
loT-Based Distribution Transformer CONDITION MONITORING SYSTEM
The proposed IoT-based distribution transformer condition monitoring system enables real-time monitoring of distribution transformers, identifying such deviations as overload conditions and overheating.
Wi-Fi 6 AND Wi-Fi 7 Powering The Next Wave of Smart Connectivity
Wi-Fi 6 leads with faster data rates and reduced latency while upcoming Wi-Fi 7's backward compatibility will facilitate gradual upgrades from Wi-Fi 6, easing transitions. However, advanced features like multi-link operation (MLO) and ultra-low latency may command a premium, making Wi-Fi 7 suited for high-end applications.
CHARGE FORWARD: High-Voltage Batteries And MSMEs Can Fuel INDIA'S EV REVOLUTION
A nuanced explanation of low- and high-voltage EV batteries by Dr Gokhale, Vice President for Battery Technology at JSW Energy, illuminates their advancements and influence. The essential role of MSMEs and academia in developing a strong EV ecosystem emerges, marking their significance for India's push towards self-reliance in this innovative field.
"MILES TO GO Before I Sleep"
A teacher illuminates the path to success through the light of knowledge, yet some teachers extend that light to society through their contributions and research. Known as the architect of the modern M3 electronic voting machine (EVM) and the voter verifiable paper audit trail (VVPAT) that transformed India's democratic process, Prof. (Dr) Rajat Moona's journey began in the modest town of Bareilly. Here is his story, as recounted to and written by EFY's Yashasvini Razdan.
STARTUPS & INNOVATORS
1 One Charger To Charge All Your Devices | 2 Harnessing AI Technology For Efficient Pest Management | 3 Wireless Light-Based Communication With Velmenni's Technology
