Introduction: Emergency Mobile Charger Using DC Motor

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This is a hobby project which can be made by anyone following some very simple instructions. The charger works on the principal of DC motor being used as a generator converting mechanical energy to electrical energy. But since the voltage required by a phone is 5V a voltage regulator IC 7805 is used to get the desired output voltage from the DC motor.

For more information and details, click here :

Step 1: Items Required

1. DC motor 12V – 60RPM: Geared motor most suitable for this project. (Available here:

2. Voltage regulator IC 7805: This will give you constant output voltage, doesn't matter what the input voltage is. (Available here:

3. Male – female USB cable: The female end is required to connect the USB cable of the phone to the generator. (Available here:

4. Glue Gun (Available here:

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Step 2: How It Works?

When the shaft of the DC motor is rotated a DC voltage is induced at the terminals. But since its not possible for a human being to maintain a constant RPM of the shaft the output voltage of the motor keep varying at some time going beyond 5V which is above the save limit of the phones. Thus an IC 7805 is used to regulate the voltage and to make sure that we have a constant 5V.

The following are the steps to be followed:

1. Cut out the female end of the USB cable and clip of the data cables. (We require only RED and BLACK wires)

2. Now using a solder iron make the following connections as given below :

3. Paste the IC 7805 and female USB port on the surface of the motor using a glue gun so as to secure it on the surface.
4. Use a right angled iron rod at the shaft as handle for the ease of rotation.

5. Bingo! now you are ready to test your ‘Emergency Mobile Charger’

Step 3: Detailed Video

For more information watch the video.