Solar Freaks

Hi guys, new to teh forums, im looking to build a small scale solar project with a ~1w solar cell, currently i am getting about 1v out of it and would like to build a small usb charger, i came across this paper which i think would be idea, it is for low power devices and should work well, however there are no component values given on the circuit diagram, or how to build the blocks in the lower part i didnt find anything that could help either, if anyone could help then this would be great
http://www.iis.fraunhofer.de/Images/mpp ... 134728.pdf

That's an interesting paper.

They aren't using a solar panel - they are using a Thermo-Electric Generator. I wonder what the price per watt is to install TEGs on a temperature gradient, like, say, the back of a solar panel?

Also interesting - their MPPT is done using an analog circuit. I'm not sure, but it looks like they have a shunt for power conversion to the output - is that just a snubber?

I doubt the MPPT they are doing would work for a solar panel - the power curve is in a different place. You'd have to start by simulating their circuit running on a model of a solar cell for the power source.

but the purpose of a maximum power point tracker is to find the peak in the power curve, nomatter where it is. the analog control circuit is used as the input for their boost converter

edit, from the paper

"The paper proposes a simple MPPT analog circuit
with only four low power operational amplifiers to use
in combination with solar cells or TEGs. The MPPT
circuit controls the duty cycle of a step-up converter
based on coupled inductors."

so it does work for solar cells

I didn't see that when I read the paper. Ok, that sounds interesting.