# Is there any simple way to make a solar engine work with 12 volts using a 20W solar panel?

I want to use a 20 Watt panel I have to run a big 12volt engine, however the power of the sun is not always powerful enough to get it running continuously.

So I though of solar engines, simple circuits that charge capacitors until a usable voltage and then discharges making the engine run for a few seconds, however, most of these are based on very small voltages, - about 3 volts.

Does anyone here knows how to make it run on 12volts from the panel?

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6 years ago
It's a 20W panel, 20W is the most you'll get out of it and at 12V that's ~1.5A.

You can charge batteries, and run the motor from them.

L
caarntedd6 years ago
Batteries.
orksecurity6 years ago
Think batteries, not capacitors. Use the panel to charge batteries. When battery charge rises high enough, run the motor; when it drops low enough, cut the motor off again and just charge for a while.

And/or find a more efficient motor.
Aqlor (author)  orksecurity6 years ago
Even if I used a battery I would have the same problem:

imagine I would do exactly as you said, use a charge controller and charge the battery and then run everything from there until the battery is almost empty (you can think of the battery as my capacitor). How would I do that automatically -> like a solar engine does?
6 years ago
Electronically, in the simplest method, you monitor the voltage on the battery, and when its more than a certain figure, you turn on the load, when its less than a certain figure you turn it off again.

In a refined version, you have an electronic "gas gauge" that measures how much energy you took from the battery, and how much you put in with the charger, then you switch the load as appropriate.

What you want to do isn't terribly difficult to do. A circuit called a comparator, and a relay will do it. A simple way is to buy an off the shelf device called a reset generator, used to protect computers from low batteries as the comparator block and add some resistors to set the trigger levels.

Steve
Aqlor (author)  steveastrouk6 years ago
I was going for the simplest method you described above, how could I do that?
With the comparator? How would I set the minimum voltage?
6 years ago
If I draw a circuit, can you build it ?
Aqlor (author)  steveastrouk6 years ago
Yeah I should be able to build a circuit, I just don't know when
6 years ago

http://home.cogeco.ca/~rpaisley4/ComparatorWindow.GIF
Here's a circuit example. You'd need to put a low current relay in for the load. Steve
rickharris6 years ago
Go stirling engine