electrical grid project for students in middle school

[Joe Caughey]

Help with variable dc voltage controling a potentiometer

Hi, my first post as well. Not even sure this is the correct place to post this. sorry if not.

I'm trying to build a renewable resource lab using small DC motors and small solar panels for a input voltage I'm thinking will be .5V to maybe 2V output maybe. My question is: is there a way I can build a device that takes the output of the students generators and control the variable output of a 3V battery display? So depending on the power generated the output (lights or a meter) will vary too? I think this will help the kid understand the concepts but make it much more exciting.

 

[Mr RB]

Use a analog meter (needle-dial type) and connect a visible load like a light bulb of the correct size. You can get nice large ones about 4" across.

Then calibrate the analog meter in power (watts into that load) and print a new dial label for it. maybe with some nice coloured zones on the dial.

The dial of the meter going up and down is a good visual indicator that is easier to grasp then numbers. And the light bulb lighting up brighter and brighter is entertaining and very easy to grasp too as "more power is now being generated".