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Using LEGO Solar Panel to power the NXT

Posted: 27 Dec 2010, 19:58
by ricardocrl
Hello all,

I was wondering if it is possible to power the NXT using the new Solar Panel (http://www.bricklink.com/catalogItem.asp?P=bb490), in some way.

I would like to run NXT creations using only solar energy, like it is possible with the dSolar, from Dexter Industries.
Let's assume that I am OK to make the necessary changes on the hardware to convert the PF output of the Solar Panel to the NXT power supply plug.

[1] - Does anyone knows what is the maximum current/voltage it can deliver? From this image you can read 5V and a current from 4 to 20mA, depending on the light source. I can imagine that we can get better results from stronger light sources.

[2] - And what about getting parallel combination of several solar panels, plugging the solar panel PF outputs one over the other?

[3] - If it works, is it obvious that it will work, charging the new DC NXT rechargeable battery?

This would be nicer to do the actual experiments, but it's quite expensive, if it ends not working. :-)

Cheers,
Ricardo Oliveira

Re: Using LEGO Solar Panel to power the NXT

Posted: 27 Dec 2010, 20:55
by aagruntpuddock
I read somewhere that the NXT brick switches itself off when the voltage drops to 6.5 volts so one panel would not be enough.

Two would give you 10 volts but you would have to check it was not much mote than that in better light because the NXT motor controller can apparently only take 10.5 v max.

There is always this, of course :- http://www.dexterindustries.com/Products-dSolar.html

Re: Using LEGO Solar Panel to power the NXT

Posted: 27 Dec 2010, 22:23
by mattallen37
If the NXT is only running the processors, screen, and speaker (no motors or sensors), I would think it should have absolutely no less than 50ma at it's disposal. NXT motors can draw over 1A each, so if you want to do anything mechanical, I would discourage using solar power.

In my opinion, you would need no less than four panels (two sets of two in parallel in series) to get the NXT to do any substantial processes (no motors or sensors). I don't think it is anywhere near worth the money, weight, size, or hassle to use solar panels to run an NXT robot.

Re: Using LEGO Solar Panel to power the NXT

Posted: 28 Dec 2010, 08:33
by HaWe
I already tried it using a solar panel for automobiles. It produces 10-16V output -sth like this:
Image
I attached it to the NXC NiCd accumulator pack with a Solar Battery Charge Controller in between, and it works fine (of course not enough power / current for direct supply but enough to charge the accu pack intermediately when the robot is idle).

Re: Using LEGO Solar Panel to power the NXT

Posted: 28 Dec 2010, 11:42
by ricardocrl
Hm, I know that if we connect the solar panel to the energy meter (http://www.bricklink.com/catalogItem.asp?P=bb491), we can get an output of 9V. That would solve the series link, but I don't know which is the maximum current drawn in the input and output.

If the money was not a concern, it would be very interesting to try something big, like a big square of some panels, on the top of a creation. Even if I would need to turn on lots of lights just to show that it works with solar power (not for practical use).

Re: Using LEGO Solar Panel to power the NXT

Posted: 28 Dec 2010, 16:03
by nxtboyiii
I agree with Matt. It is not worth the money, time, and frustration.