In this post I have explained a simple audio source selector circuit using a single push button and a couple of relays. The idea was requested by one of the avid readers of this blog Mr. Mike. Design Description The request can be seen as given below: I need a circuit diagram to add a […]
Archives for 2025
DHT11 Humidity, Temperature Sensor: How to Use and Interface with Arduino
We are now going to talk about one small cheap sensor that we call DHT11, and we can use that for measuring humidity and also temperature. You can see that many Arduino people like this sensor because it is very simple and also very low cost, so anybody can buy and try. The DHT11 can […]
100A AC Load Monitoring Circuit using Arduino, Watt Limit, LCD, Alarm, Auto Shutdown
In this project we are going to make one very useful grid power protection circuit. This will be like a power guard system which we can use in homes or apartments to monitor the wattage of the load and also to cut off the load automatically if it starts taking too much wattage, more than […]
Smart Bathroom Exhaust Fan Controller Circuit with Sensors
So here we are now making one automatic smart exhaust fan controller system using Arduino UNO which will work for three bathrooms that are all connected to a single ventilation pipe and one common exhaust fan. This whole project is going to be based on PIR sensors for human detection, VOC sensors for odor detection […]
H-Bridge Sine Wave Inverter Circuit using Arduino
In this article I will explain how we can build an Arduino-controlled H-Bridge sine wave inverter circuit using some easy parts. So this thing will basically convert DC into AC but in a way that looks like a sine wave, right? We are using an Arduino to generate PWM signals and these signals will drive […]
Real MPPT Solar Charger Circuit Using Arduino, LCD, and Manual/Auto Switch
So in this article we are trying to make a true MPPT solar charger project using Arduino which will charge a 12V battery from a solar panel and will use MPPT logic to always extract maximum power from the solar panel. That means that even when sunlight changes, we try to adjust PWM duty cycle […]





