This Simple Thermistor Based Fire Alarm Circuit is very small, simple and smart. It uses a thermistor to sense heat fast. When temperature goes high the circuit wakes up and makes loud sound. No microcontroller, no complex parts. Only few components and we get a working fire alert that anyone can build at home Circuit […]
Heater and Temperature Controllers
Temperature Controlled LED Circuit
This small Temperature Controlled LED Circuit can feel the heat! When place near warm thing, it sense temperature and LED glow. It work very simple using one diode and one transistor only. No microcontroller, no sensor IC, just few parts. We can build it easy at home and see how heat make light turn ON. […]
Simple Digital Thermometer Circuit with IC LM35
This is a small and Simple Digital Thermometer Circuit with IC LM35. It uses LM35 sensor IC. The circuit show temperature in voltmeter. It is cheap and very easy to make. Good for students and DIY beginners. Circuit Working: Parts List: Component Value Quantity Resistors 10k 1 Preset 2k 1 Semiconductors Voltmeter 200mV 1 IC […]
Dual LED Temperature Indicator Circuit
Dual LED Temperature Indicator Circuit light one LED when hot and other when cold. It uses IC LM35 temperature sensor, CA3130 op-amp and two BC547 transistors. IC 7805 change 9V to steady 5V and if there is 5V already then we can connect directly. IC LM35 gives 10mV more for every 1°C rise. Output goes […]
Temperature Based DC Fan Controller Circuit using Transistors
Temperature Based DC Fan Controller Circuit using Transistors turns ON when hot, stops overheating and saves energy. Thermistor checks temperature and runs fan as needed. The circuit works on 12V battery or 12V power supply. Circuit Working: Parts List: Component Type Value Quantity Resistors (All resistors are 1/4 watt unless specified) 1.5k 1 1k 1 […]
Temperature Controlled Fan Circuit for Audio Amplifiers
Amplifiers make heat when working. Too much of heat make it work bad and can die soon. This Temperature Controlled Fan Circuit for Audio Amplifiers keep amplifier cool. Fan starts only when amplifier is hot. If volume is low and less heat then fan stays OFF and saves power. The circuit is made with LM311 […]