Solar Cell

[patrick]

Is there any kind of solar cell that can provide 5mA and 3V under room
conditions?

I think many portable devices can be powered by solar energy if the
above figure can be archieved.

Patrick

 

[Tim Wescott]

patrick wrote:

Is there any kind of solar cell that can provide 5mA and 3V under room
conditions?

I think many portable devices can be powered by solar energy if the
above figure can be archieved.

Patrick

Certainly. Large ones.

output power = illumination * area * efficiency

You can't change the illumination, you can't change the efficiency much,
but you can certainly change the area!

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 

[mike]

patrick wrote:

Is there any kind of solar cell that can provide 5mA and 3V under room
conditions?

I think many portable devices can be powered by solar energy if the
above figure can be archieved.

Patrick

If by cell, you mean multiple cells, Sure!
All you need is a BRIGHT room.
Now, If you said how much illumination you had, someone might be able to
tell you how big it would have to be and how much it might cost.

Answers are always easier when there's an answerable question.

Once you get past the "clock" and "calculator", what devices do you
envision that will run on 3V 5ma of interruptible power that takes up
space measured in square feet?
mike

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[Ian Stirling]

patrick <patrick1957@gmail.com> wrote:

Is there any kind of solar cell that can provide 5mA and 3V under room
conditions?

I think many portable devices can be powered by solar energy if the
above figure can be archieved.

Your basic problem is the incoming wattage.
Take a "100W" bulb.
Out of this, comes 10W or so of light energy.
As you need to intercept about 1/60W, you need to catch 1/600th of the
whole output.
Taking into account cell efficiency, more like 1/80th of the total output.
Or about a 30cm solar panel 1m from the bulb (assuming that it radiates
into a hemisphere.

 

[redbelly]

Ian Stirling wrote:

Your basic problem is the incoming wattage.
Take a "100W" bulb.
Out of this, comes 10W or so of light energy.
As you need to intercept about 1/60W, you need to catch 1/600th of the
whole output.
Taking into account cell efficiency, more like 1/80th of the total output.
Or about a 30cm solar panel 1m from the bulb (assuming that it radiates
into a hemisphere.

FYI, solar cells are sensitive into the near-IR, up to about 1 or 1.1
micron wavelengths. So they are not limited to just the visible light
output from the bulb.

Mark

 

[Ian Stirling]

redbelly <redbelly98@yahoo.com> wrote:

Ian Stirling wrote:

Your basic problem is the incoming wattage.
Take a "100W" bulb.
Out of this, comes 10W or so of light energy.
As you need to intercept about 1/60W, you need to catch 1/600th of the
whole output.
Taking into account cell efficiency, more like 1/80th of the total output.
Or about a 30cm solar panel 1m from the bulb (assuming that it radiates
into a hemisphere.

FYI, solar cells are sensitive into the near-IR, up to about 1 or 1.1
micron wavelengths. So they are not limited to just the visible light
output from the bulb.

Oops, true.
So, maybe a 15cm panel 1m from the bulb, being very generous.