Solar power mobile charger

Introduction

This circuit helps you to charge your mobile phone battery and also some rechargeable battery with solar energy, before trying this circuit take extra care in battery polarity and current rating, if anything goes wrong the battery might explode.

Circuit Construction

Here the circuit utilize 6V/500 mW solar panel, and then single PN junction diode 1N4007 connected towards positive line of solar panel this will avoid reverse polarity. An green LED connected across the solar panel supply line after the C1 capacitor which provides status of supply output from solar panel.

You can remove R2 and LED if you don’t need light indicator. SL100 transistor with 4.7V/400mW zener diode provides regulated supply from solar voltage. Choose the zener diode specification according to your need. Here the zener diode connected in base of SL100 transistor with reverse biased polarity.

Working

Expose the solar panel in sunlight, that solar energy will be converted as voltage by the photovoltaic device (solar panel cell), then the green LED glows here the intensity of this LED varies depends on the voltage produced by the solar panel. The zener diode reduce and regulates voltage and the SL100 transistor drives output voltage.

Test Points

•  tp GND – test point common ground
• tp 1 – To check solar panel voltage – 5V to 6V
• tp 2 – To check Zener voltage – 4V to 4.7V
• tp 3 – To check output – 4.5V – 4.7V