# Help with solar power

Discussion in 'Electronics Homework Help' started by Osga21, May 4, 2013.

1. ### Osga21

1
0
May 4, 2013
My chemistry/physics teacher told us to make something solar powered, and because I love remote controlled cars, that is what I'll be building.

I'll buy 2 2V solar cells to power a 3V motor + the wheel servos(?).
My question is, will I "blow up" the engine if apply that voltage to the 3V motor?

Thank you

P.S.: What are the most common toy motor voltages? I will buy a car in a chinese shop to cannibalize and I don't know anything about the motor, I was thinking on buying a car that only takes 2 AA batteries (1.5 volt each), and was thinking that might give me the aproximate voltage of the motor (~3V)

2. ### Harald KappModeratorModerator

11,531
2,656
Nov 17, 2011
The issue ie less the solar cells blowing the motor. More probably the motor will drain more current than a small solar cell can deliver.
But the idea is viable. Measure the current requirements of the motor and get sufficiently powerful solar cells. Starting with a car that runs from 2 AA cells is a good idea.
You may need to add some electrolytic capacitors in parallel to the solar cells. These capacitors can support short current surges e.g. when starting the motor from stop or when additional energy is required by the servos. In a power supply you would typically use 1000µF per 1A of current, so this should give you an idea how big the capacitors should be considering peak current consumption of the car.

3. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

25,497
2,838
Jan 21, 2010
Here is an interesting video.

An interesting consideration would be how large a solar panel you could lug around.

In full sun, you might be able to leave it to charge for a few minutes and then drive a bit.

Huge capacitors (tens of Farads and beyond) would require a long time to charge, even with a big panel.

You will need to carry as big a solar array as you can. That may mean gearing down the motor so the vehicle can carry a larger weight, and perhaps using bare solar cells rather than panels (with the extra weight of glass and metal etc.

You could also google "beam robot" to get an idea how lots of people have made stuff happen using pretty feeble amounts of energy.