This tutorial shows you how to make a phone charger which uses any DC source (AAA/AA/SLA battery) as input and is efficient in terms of power utilization. We’ve been holding onto 7805 regulator IC from a very long time and hence a question may arise as to why we are not using the same this time. Well all these days we didn’t care about the efficiency since it was either a low current application or ones which didn’t run completely on battery but this time it is different. This time our aim is to create a device which runs on battery and needs to be utilizing the battery’s energy efficiently.

During power outages, and all the batteries around your home drain away, the only option left for you would be this. This tutorial shows you how to charge a phone using a 12V DC motor and a couple of other parts.A DC motor can also work as a DC generator and vice-versa since their construction and operating principle are similar. So I would be using a 12V DC geared motor as a generator since we need a power source to charge our device. 

Latest mobile chargers are kind of power supply units that use the Switched Mode Power Supply (SMPS) technology. To understand the working phenomenon of a mobile charger, we need to understand the concept of Power Supply Unit (PSU). PSU is a device that transfers electrical energy from one end to another by changing its fundamental characteristics according to the requirements. Example of a PSU is an application that converts AC mains voltage to regulated DC voltage. PSUs can be of two types depending on the mode of operation – Linier and Switching. In these switching mode chargers, energy transfer is done by continuously switching electrical components (inductor, capacitor, etc) on and off. We can control the output voltage/current by varying the duty cycle, frequency or the corresponding phase.