Solar Charger Circuit Project
Take advantage of the sunlight and use it as a power source. It can at least save on electricity prices continuing to rise, or be of help on a camping trip, or while traveling.
The Circuits Schematics Electronics blog has a schematic of simple power plant can be created and used to fill your motorcycle battery, your ebike battery, or for emergency lights:
The circuit is designed to charge a 12 volt battery, but I wanted to see if it would simply charge 4 AA NiMH batteries (4 to 5.6 volts).
So, I went about putting it together on a breadboard.
|Solar Charger Circuit Project from Circuits Schematics Electronics|
I was curious if I could use this to charge 4 AA NiMH batteries, and was not disappointed.
Therefore, first off, I have to point out that I am not using their circuit as designed.
Notably, the specifications call for a 4V, 200 Amp solar panel, and a ferrite rod. I did not use either. I do not have the BY207 (Diada 5 Ampere diode). Nor am I using a 12 volt battery.
You can use a ferrite rod, possibly from an old AM radio. I don't have a ferrite rod, but I thought I would try it with toroids, as toroids I do have.
Also, the circuit calls for a 4V, 200 Amp (total) solar panel, but I only had a spare 6 volt, 1 watt solar panel.
The specifications call for a BY207 (Diada 5 Ampere diode), which I do not have.
Instead, I tried a 1N4735A, 6.2V, 1 watt Zener diode.
The circuit is designed to charge a 12 volt battery, but I wanted to see if it would simply charge 4 AA NiMH batteries. So, I went about putting it together on a breadboard.
However, I did get some results. At first, it did not appear to generate enough voltage or amps for my AA batteries. With a little experimentation with the number of windings on the toroid, I was able to get some decent figures for the voltage required to charge my AA batteries.
It appears to respond to an increase in the number of turns of wire on the toroid.
I have 22 guage wire available, and a blue toroid from Digi-Key. The toroid spec out as Inductance Factor of 5.46µH and Permeability of 4300.
The circuit seems to work well for AA batteries when I cover the toroid about 2 times, or for about 60 turns of 22 guage wire. I don't have a micro Henry meter, so I cannot specify what I have in those units at the moment.
Again, this is not how the circuit was designed to be used, but I was happy to see that I could modify it for this purpose.
Currently, I am testing in ambient light, such as what you might get in the shade, or when indoors. This one appears to under perform both the use of the IC 497, and also under performs the 3 Volt to 9 Volt Converter that I have posted elsewhere.
However, it is much simpler to build, it is using parts that are generally available, and again, I am not using the circuit as designed. But, I was happy to see it respond to charging AA batteries.
Make a Solar AA Battery Charger by TL497 (my review)
3V to 9V Converter (my review)
Currently testing for parallel charging, which is typically harder to do than charging in series.
You may get better results from charging in series.
I will be looking at variations, such as number of turns on the toroid, serial vs. parallel charging, ambient light, etc.
Update Sep 7, 2015:
I have yet another AA charging circuit posted here: