Alt-BEAM Archive

Message #01700



To: Zulu 35 zulu35@singnet.com.sg
From: Steven Bolt sbolt@xs4all.nl
Date: Tue, 23 Mar 1999 15:38:04 +0100 (CET)
Subject: [alt-beam] Re: Emulating a solar cell


On Tue, 23 Mar 1999, Zulu 35 wrote:

> hi guys, i was just fooling around with my photopopper circuit just now
> when it hit me that i can actually use a : 1)cap 2) voltage regulator
> 3)battery to emulate a solar cell and it does work!
> now can someone tell me the pros n cons of this method versus the method
> recommended in the suneater's webpage?

The idea of having a resistor between your regulated supply or
battery and your SE is that the supply will be reduced to a small
and known current, so you can simulate a small solar panel in
different light levels.
For instance, you have an SE with a switch-on trigger level of 2V.
Your battery is 6V. If you connect it directly to the SE, the motor
will run very fast and continuously, which says nothing whatsoever
about the SE.
Suppose you want to know what happens if the solar panel supplies
about 3mA at your trigger level. You divide 6 - 2 by 3mA and get
1K3, for which you take 1K2. Put that between your battery and your
SE, and the circuit will perform as if a small solar panel in not
so good daylight is connected.

Having a resistor in between also keeps your parts alive, if you
happened to misconnect them.

> also.. i'm not sure about this.. but is it actually possible to replace the
> 1381s with a voltage regulator too?? from where i live, 1381's are as rare
> as an UFO sighting.. *sigh* so if its possible, then maybe i can stop using
> the FLED solarengines :)

Try SunEaters :)
Or Ken's Micropower SE, or Wilf's FLASH SE, or dream up something
new...

Best,

Steve

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# sbolt@xs4all.nl # Steven Bolt # popular science monthly KIJK #
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