Homemade portable USB mobile charging circuit diagram || Homemade USB rechargeable power bank Circuit diagram

USB chargers are very popular now a day. According to national survey research with in 2015 year 80% of the mobile phone users will be smart phone users. As you know most of the smart phone has the facility to get charge from USB. Sometimes it is hard for us to carry phone charger to anywhere or sometimes we had to go some place where power cut is the regular incident or in some part of village there is no power supply. So get rid of this problem one must have a rechargeable USB power bank. This tutorial will guide you how to make an USB charger and USB power Bank.

Circuit Diagram of Rechargeable USB Power Bank

Parts required to build USB Power Bank

• 5 1N4007 Diodes
• LM7809 Voltage regulator IC
• LM7805 Voltage regulator IC
• Rechargeable 9V Battery 
• USB Cord
• 100uf and 2200uf capacitors

How the USB Power Bank Charger wok?

          The Power Bank circuit can be divided in to three segments for better understanding. First part of this circuit is AC to DC conversion circuit. Here a step down transformer and bridge rectifier is used to convert AC 230 volt to DC 12 volt. To filter the DC voltage a filter circuit has been used.

          Second part of this circuit is to stabilize the voltage and regulate to 9volt and then charge the battery. Here a diode has been used to block current flow in reverse direction.

          In the last segment another 5Volt regulator has been used so that it can charge your Smart phone.

[N.B. Voltage and current are extremely hazardous for health. Familiarize yourself and take safety precautions before working with them]