A simple cell phone charger with timer circuit is presented in the following article, which could be used for charging a given Mobile phone for a specified predetermined length of time. The idea was requested by Mr. Saad. Circuit Objectives and Requirements Could you design me this charger circuit ? Input 230V 60 Hz, and the […]
Based
Arduino based Battery Over Discharge Protection Circuit
In this post, I will show how to construct a over discharge protection circuit for 12v battery using Arduino which can protect 12V SLA battery against over discharge, and also protect the connected load from over voltage in case of overcharged battery is connected. Understanding Battery Charge/Discharge Rates All the batteries have natural decline, […]
How to Make a RFID based Attendance System
In this post I will show how to construct a RFID based attendance system, which can record attendance of 12 students / staffs for a given time window and this system can record up to 255 attendances per person. What is RFID Attendance System We don’t need any introduction regarding the RFID based attendance system, […]
Single LM317 based MPPT Simulator Circuit
To make this simple MPPT circuit we first modify a standard LM317 power supply circuit into a buck converter then configure it with a solar panel for implementing an MPPT function. Modifying a LM317 Power Supply into an MPPT Solar Optimizer In our previous article I have explained how a standard LM317 power supply could […]
GSM Based Cell Phone Remote Control Switch Circuit
This circuit will allow you to control any electrical gadget from any part of the world through your cellphone remotely, that too without spending a penny for the individual commands. Circuit Concept Whether it’s you vehicle, your basement door, your mansion gate or simply the air conditioner of your house, everything can now be switched […]
Transistor based 3 Phase Sine Wave Generator Circuit
In this post I have explained a very simple 3-phase sine wave generator circuit, using only three bipolar transistors and a few passive components for initiating the desired three phase output. How it Works Referring to the 3 phase sine wave generator circuit we can see three identical transistor stages configured in a cross coupled […]