The circuit has three parts: the sensor, main control unit, and relay driver. It works on 230V AC mains. A bulb used in the circuit acts as a load for demonstration purpose. When the room temperature goes beyond the set limit the bulb switches on automatically. The author's prototype is shown in Fig. 1.
Circuit and working
Circuit diagram of the temperature controlled switch is shown in Fig. 2. The circuit comprises step-down transformer X1, bridge rectifier BR1, 5V voltage regulator 7805 (IC1), temperature sensor LM35 (IC2), op-amp LM35 (IC3), 5V single changeover relay RL1, and a few other components. Capacitor C1 connected across the supply terminals minimises any ripples or noise signals in the voltage.
The circuit needs 5V DC to operate, which is derived from the 9V, 500mA secondary side of transformer X1. The 230V AC mains is connected to the primary of X1 via CON1 in the circuit whose 9V AC secondary is connected to bridge rectifier BR1 for rectification. The rectified and filtered voltage (by C1) is given to IC LM7805 to get regulated 5V for the circuit.
Glowing of LED1 indicates that 5V is being supplied to the circuit.
この記事は Electronics For You の January 2023 版に掲載されています。
7 日間の Magzter GOLD 無料トライアルを開始して、何千もの厳選されたプレミアム ストーリー、9,000 以上の雑誌や新聞にアクセスしてください。
すでに購読者です ? サインイン
この記事は Electronics For You の January 2023 版に掲載されています。
7 日間の Magzter GOLD 無料トライアルを開始して、何千もの厳選されたプレミアム ストーリー、9,000 以上の雑誌や新聞にアクセスしてください。
すでに購読者です? サインイン
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
