The growth of mobile phone market is phenomenal in recent years and the need for charging the mobile battery is required anytime and anywhere. In many developing countries the grid power is not available for few hours to several hours on daily basis especially in semi urban and rural areas where the mobile phones are the essential communication device. A coin based universal mobile battery charger is designed and developed in this project. This device is like a vending machine for mobile battery charging and the user has to plug the phone into the adapter and insert a coin for charging at a constant current for a definite duration.   The mobile battery charger starts charging a mobile connected to it when a coin is inserted at the coin insertion slot at the input stage. A sensor attached to the coin insertion slot accepts the coin into the battery charging unit and start charging the mobile battery for a specific period controlled by the software of the microcontroller. LCD is used to display the charging time of the mobile and the duration of the charge of the mobile phone. The buzzer beeps when the duration for the charging time is below 20 second.   In this project we are using GD007 coin sensor to insert the coin. When coin is inserted in the coin sensor, the coin sensor gives input to the microcontroller. Then microcontroller drives the Relay and the mobile phone is charged at 60 seconds duration. If coin is not placed, the microcontroller will not drive the Relay so the mobile won’t get change.              

The objectives of the project include:  

1. Sensing of the coin through gd007 coin sensor.
2. Visible alerts using LCD.
3. Audible alerts using Buzzer.
4. This system is very useful for mobile battery charging.

             

The major building blocks of this project are:

1. Regulated Power Supply.
2. PIC Microcontroller
3. coin sensing module
4. LCD display with driver.
5. Buzzer
6. Charging circuit.
7. Relay.
8. Crystal
9. Reset button
10. LED indicators.

             

Software’s used:  

• PIC-C compiler for Embedded C programming.
• PIC kit 2 programmer for dumping code into Micro controller.
• Express SCH for Circuit design.

               

Regulated Power Supply:        

               

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