Re: pinhole speakers and hydrogen peroxide

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From: Algis Sodonis (asodonis@urbanschool.org)
Date: Tue Jan 18 2005 - 21:13:00 PST 

Message-id: <fc.000f76110078a8e13b9aca00c01bf054.78a952@urbanschool.org>
Date: Tue, 18 Jan 2005 21:13:00 -0800
Subject: Re: pinhole speakers and hydrogen peroxide
From: "Algis Sodonis" <asodonis@urbanschool.org>

Joe,

Here I was hoping there was some cool demo using speakers to make hydrogen peroxide decompose.

anyway, I've done the speaker thing (thanks to modesto, also) many times. Here are some tips:
        make sure your coil is well stripped to give you good electrical contacts. If you are using magnet wire, it often looks like it is not insulated, but needs some scraping with sandpaper or a utility knive to get off some of the enamel.
        If you're not using the magnet wire (thin, enameled wire) consider using it. You can get some at Radio Shack.
        Often, it works, but it is very faint. I find that small diskmans don't have much power output and produce weak sounds. Large boomboxes should work better. Consider also having more loops of the coil and stronger magnets. I find that using stronger magnets like hard drive magnets improve it, but using more ceramic magnets has little effect. (though I have ok success with simple ceramic magnets)
        Finally, make sure if you are using a stereo jack (vs. a mono jack) you try a ground and one of the hot connections. If you're not sure, just try all combinations of two out of the three connections on the jack.

Hope this helps.

Algis Sodonis

The Urban School of SF.

Oh, you should definitely consider making the mouth speaker using a motor and a wooden dowel. All my kids get a fantastic kick out of this!

"Pinhole Listserv" <pinhole@exploratorium.edu> on Tuesday, January 18, 2005 at 8:33 PM -0800 wrote:
>
>Hello,
>
>I have two problems that I hope someone can help me with.
>
>First, I recently tried to build a simple speaker out of a copper coil, magnet, and a cup. I plugged it into the boom box that I have in my classroom and it was a failure. A year or two ago I went to a class that Modesto gave on this very thing, and I thought I did it correct. I someone has had some success with this and can offer some suggestions, I would really appreciate it.
>
>Secondly, someone asked me how hydrogen peroxide acts as a disinfectant. I assume that it is some sort of oxidation process, but...
>
>Thank you for your help,
>
>Take good care,
>
>Joe
>
>
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