Recent content by aniseed

TL;DR Summary: I approach a rocket acceleration problem using two approaches: F=d(m*v)/dt and F=ma. The resulting differential equations are different. What am I doing wrong? We have a ship with a mass-reaction rocket engine floating in space. The initial mass of the ship (including fuel) is...

My niece is in her first year of public high school in Japan, and her science textbook introduces the concept of elements, atomic number and charge, then shows the periodic table. It states that elements in the upper right hand side of the periodic table tend be become anions, and elements in...

Hi, It looks to me like you have a Y-arrangement inside a Delta-arrangement. You could tackle this by say, converting the Y to a Delta and then you get two Deltas 'on top of each other', i.e. in parallel. Here are the details on Y-Delta transforms: http://en.wikipedia.org/wiki/Y-%CE%94_transform

You are correct, vk6kro. It was a lot less sunny when I took the measurements in my last post. The sun was setting at the time. I have redone the test, this time including 510 and 1000 ohm resistors, and under sunny conditions. Attached are my results and graphs. In short, the knees are...

vk6kro, thanks for the clarification. You were right, I merely moved the panel around. I re-did the test using different resistors, and got the behaviour that you described. Attached are the results, in case anyone is curious.

I have tested my two 5V solar panels, using a 20R load as recommended by vk6kro and taken a few readings. The results are in the attached .xls file. The results show that each panel is working well and has a nice linear voltage-current characteristic. I have gone back and connected just one...

Thank you for the replies and suggestions. I will take more measurements of the panels under load, see if any of them is defective. I will also try to charge the batteries from just the one 5V panel again, see if I made a mistake the first time round. At any rate, now I have confidence...

I'm new to electronics and have been looking into building a solar cell charger for NiMH batteries. I got hold of a pair of small solar panels rated at 5v open circuit voltage, and 100mA short circuit current. I confirmed this under bright sunlight with a multimeter. Each panel will easily...