Thanks so much for sharing! I think I will try the joule thief at Mission Science! What a great use of &quot;dead&quot; batteries!.<div>-Mario<br><br><div class="gmail_quote">On Tue, Nov 9, 2010 at 4:48 PM, Michael Shiloh <span dir="ltr">&lt;<a href="mailto:michaelshiloh1010@gmail.com">michaelshiloh1010@gmail.com</a>&gt;</span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">i&#39;ve made joule thiefs with kids. the circuit is incredibly tolerant of<br>
the quality and number of windings on the transformer, and makes for a<br>
great activity.<br>
<br>
a dab of hot glue to hold the wires in place before the kids start to<br>
wind is a great help.<br>
<br>
kids love the idea of a flashlight that runs off dead batteries.<br>
<div><div></div><div class="h5"><br>
On 11/08/2010 05:47 PM, Mitch Altman wrote:<br>
&gt; Another way cool way to run LEDs off of way dead batteries is by using a<br>
&gt; &quot;joule thief&quot;:<br>
&gt; <a href="http://www.evilmadscientist.com/article.php/joulethief" target="_blank">http://www.evilmadscientist.com/article.php/joulethief</a><br>
&gt; (No need to buy any chips at all! Just a transistor, a resistor, and a<br>
&gt; coil.)<br>
&gt;<br>
&gt; Mitch.<br>
&gt;<br>
&gt;<br>
&gt;<br>
&gt;  &gt; From: <a href="mailto:jim@systemateka.com">jim@systemateka.com</a><br>
&gt;  &gt; To: <a href="mailto:noisebridge-discuss@lists.noisebridge.net">noisebridge-discuss@lists.noisebridge.net</a><br>
&gt;  &gt; Date: Mon, 8 Nov 2010 17:27:36 -0800<br>
&gt;  &gt; Subject: [Noisebridge-discuss] LED driver<br>
&gt;  &gt;<br>
&gt;  &gt;<br>
&gt;  &gt; Great little article tells how to drive one or more LEDs<br>
&gt;  &gt; from old, dying batteries:<br>
&gt;  &gt;<br>
&gt; <a href="http://www.edn.com/article/510577-LED_flashlight_circuit_works_at_voltages_as_low_as_0_5V.php" target="_blank">http://www.edn.com/article/510577-LED_flashlight_circuit_works_at_voltages_as_low_as_0_5V.php</a><br>

&gt;<br>
&gt;  &gt;<br>
&gt;  &gt; This is the chip that does it (LT1932):<br>
&gt;  &gt;<br>
&gt; <a href="http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1003,C1042,C1031,C1061,P2114" target="_blank">http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1003,C1042,C1031,C1061,P2114</a><br>
&gt;  &gt;<br>
&gt;  &gt;<br>
&gt;  &gt;<br>
&gt;  &gt; _______________________________________________<br>
&gt;  &gt; Noisebridge-discuss mailing list<br>
&gt;  &gt; <a href="mailto:Noisebridge-discuss@lists.noisebridge.net">Noisebridge-discuss@lists.noisebridge.net</a><br>
&gt;  &gt; <a href="https://www.noisebridge.net/mailman/listinfo/noisebridge-discuss" target="_blank">https://www.noisebridge.net/mailman/listinfo/noisebridge-discuss</a><br>
&gt;<br>
&gt;<br>
&gt;<br>
&gt; _______________________________________________<br>
&gt; Noisebridge-discuss mailing list<br>
&gt; <a href="mailto:Noisebridge-discuss@lists.noisebridge.net">Noisebridge-discuss@lists.noisebridge.net</a><br>
&gt; <a href="https://www.noisebridge.net/mailman/listinfo/noisebridge-discuss" target="_blank">https://www.noisebridge.net/mailman/listinfo/noisebridge-discuss</a><br>
<br>
</div></div><font color="#888888">--<br>
Michael Shiloh<br>
KA6RCQ<br>
<a href="http://www.teachmetomake.com" target="_blank">www.teachmetomake.com</a><br>
<a href="http://teachmetomake.wordpress.com" target="_blank">teachmetomake.wordpress.com</a><br>
</font><div><div></div><div class="h5">_______________________________________________<br>
Noisebridge-discuss mailing list<br>
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</div></div></blockquote></div><br></div>