Showing posts with label diode. Show all posts
Showing posts with label diode. Show all posts

Monday, March 3, 2008

Table Lamp Solar Charger (Solar Charger Test setup)



After studying how to make a simple solar charger, I decide to make a fast prototype to test. I got one solar panel a long time ago, the ratings of this solar panel is unknown. The solar panel will output different voltage and current under different lighting condition, so we have to measure it before use. I measured this solar panel would output maximum 3V under bright sunlight, and output 2V under my table lamp.

Everyone got a table lamp when working in front of the computer, and the light condition will remain considerably constant when compare to the outdoor sunlight condition. It would be easy to make one simple table lamp charger.

The above diagram is my setup, I used the schottky diode (IN5819) to prevent back current flow to solar panel when the lamp is off. The diode is placed between the solar panel and the the battery holder with two AAA batteries loaded. When charging, I measured the forward voltage across the diode is 0.14V which is small when compare to a normal diode.

Initially, the voltage across 2 batteries are 1.7V, after a while the voltage is 1.81V, so it is charging right now. The charge current measured is only 0.12mA.



The current is too small, and not so sure how long it will charge up to 2V:)

Sunday, February 24, 2008

Solar Power, the green power source.

Solar Power Charger

Solar power is not a news nowadays. People are finding better ways to get power without harming the earth. To use of solar power, you need the solar panel that converts solar energy to electricity. So how to make a small solar charger for your home use? This solorb's website teaches you how to make a simple AA battery solar charger, few components are needed, a nice choice for your home project.





The project needs few solar cells, and 1 1N5818 Schottky Diode and of course the AA rechargeable battery. Why Schottky diode? this diode have less voltage drop when current flow through, it is important as we want to be sure the energy is not wasted on the diode which is only used for preventing the current through back to damage the solar panel when the charger leave in the darkness. You can also buy the solar kits from the author website as well.

Take it into real life application, you may add the solar charger to your radio! Let's read the tutorial bought you by gotwind.org "DIY Solar Powered radio for $5", the theory is the same as the AA charger.



Another video showing a home-made solar USB power charger:

Solar Powered USB Charger - Cheap And Easy To Make! - The most popular videos are a click away


A very comprehensive study on Solar power charger: REUK.co.uk - Solar Battery Charging.