X-Authentication-Warning: delorie.com: mail set sender to geda-user-bounces using -f X-Recipient: geda-user AT delorie DOT com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=laYP7UHk2QbffkA8bujCWRp508OiJkS3iVZO9mOsS5U=; b=hxDOI+Apgp41VR24/4Rs1mEw1s+UMhsIT9Bu9eHb/zCyBg0Fi6CRqeuooapRz/3QIp 7p/TX9UlOIKrYRo7HamkepNfoeIqtA1jwQCy53csKklfClhXGPeVCZzc3x1lqZH+lzRR rIvF44GSYbG50mM+HtqdG0Yogn3mFr1NafSmRtNKy2A7dAYM6LSWALvRHS+hQy7WlSId mdgRdmFJbh/MqaVjqWtVrKPN2+1QXr2ha4jPUhIliuxSqDFWx3hPCyr9cYS1wujKfpd3 9+212gvgxm3wR6ZlSJKkRrzJEluJJ6QS7me+LVOToJFbjKb/YoEvmAM/bq37+6t55Ird Ik5A== MIME-Version: 1.0 In-Reply-To: <81086e.ffa0.1361ca943e5.Webtop.22@optonline.net> References: <81086e DOT ffa0 DOT 1361ca943e5 DOT Webtop DOT 22 AT optonline DOT net> Date: Fri, 16 Mar 2012 14:23:46 -0400 Message-ID: Subject: Re: [geda-user] Daughter's Science Fair From: John Hudak To: geda-user AT delorie DOT com Content-Type: multipart/alternative; boundary=f46d0444ee0b2a92f304bb604ffc Reply-To: geda-user AT delorie DOT com Errors-To: nobody AT delorie DOT com X-Mailing-List: geda-user AT delorie DOT com X-Unsubscribes-To: listserv AT delorie DOT com Precedence: bulk --f46d0444ee0b2a92f304bb604ffc Content-Type: text/plain; charset=ISO-8859-1 I can't comment on the resistor because I am at work and don't have time to fully understand your circuit details. i would like to add some comments. You may wish to show the students how they can see the invisable magnetic field by putting some iron filings into a jar of glycerine. When you move the jar close to the nail, the metal filings will arrange themselves in the pattern of the magnetic field. You can accomplish the same thing, sort of, by putting flat cardboard around the nail, and sprinkle the filings on the cardboard - this is a little tricky because if the filings are too close to the nail they will be sucked into it. You could also get a galvenometer (or make one - web search) to show the magnetic field...a compass would also work John On Fri, Mar 16, 2012 at 1:58 PM, GENE GLICK wrote: > > > > On Fri, Mar 16, 2012 at 11:33 AM, Rob Butts wrote: > > So if I use a 1 watt 15k ohm resistor in series with the nail and an ac > outlet that will give me 8ma alternating current and that should light the > bulb? > > I don't think UL would approve :) Also, you don't want to endanger the > kids. But - if you energize one coil with a DC source, then *move* the > other coil around, you should get something to happen. Maybe a light bulb, > or maybe a current meter would show the affect. In fact, if you have time > to build a little turntable, somehow allowing the kids to spin the second > coil - that should also work. Faster spins = brighter lights, or higher > current readings - make a game out of it :) > > gene > --f46d0444ee0b2a92f304bb604ffc Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable I can't comment on the resistor because I am at work and don't have= time to fully understand your circuit details.=A0 i would like to add some= comments.

You may wish to show the students how they can see the in= visable magnetic field by putting some iron filings into a jar of glycerine= .=A0 When you move the jar close to the nail, the metal filings will arrang= e themselves in the pattern of the magnetic field.=A0=A0 You can accomplish= the same thing, sort of, by putting flat=A0 cardboard around the nail, and= sprinkle the filings on the cardboard - this is a little tricky because if= the filings are too close to the nail they will be sucked into it.

You could also get a galvenometer (or make one - web search) to show th= e magnetic field...a compass would also work

John


On Fri, Mar 16, 2012 at 1:58 PM, GENE GLICK <geneglick AT optonline= .net> wrote:
=A0


On Fri, Mar 16, 2012 at 11:33 = AM, Rob Butts wrote:
<= br>
=A0So if I use a = 1 watt 15k ohm resistor in series with the nail and an ac outlet that will = give me 8ma alternating current and that should light the bulb?

I don'= ;t think UL would approve :) Also, you don't want to endanger the kids.= =A0 But - if you energize one coil with a DC source, then *move* the other = coil around, you should get something to happen.=A0 Maybe a light bulb, or = maybe a current meter would show the affect.=A0 In fact, if you have time t= o build a little turntable, somehow allowing the kids to spin the second co= il - that should also work.=A0 Faster spins =3D brighter lights, or higher = current readings - make a game out of it :)

gene

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