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I made a electromagnetic coil out of some thinly coated magnet wire from radio shack (the red one)
I submersed it into water to heat the water up (the coil is about 12 ohms) I connected it to a 12 volt adapter (1 amp supply it is still working)
I was able to get a voltage out of the water, the coil is completely insulated how can this happen?

(EDIT)
small bubbles are forming all over the coil (I believe electrolysis )
« Last Edit: June 12, 2012, 08:25:43 pm by arduinopi » Logged

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I was able to get a voltage out of the water
How were you measuring it?

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small bubbles are forming all over the coil
If the wire is heating the water, the bubbles could just be the oxygen and other gases which form bubbles whenever water is heated. Look inside a kettle as it heats up. There will be bubbles on the heating coil long before the water boils.

Or the wire isn't as insulated as you think it is.

Pete
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Where are the Nick Gammons of yesteryear?

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Or the wire isn't as insulated as you think it is.

I think they "pin hole" test enamelled magnet wire in this way, probably salt water.
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I was using a voltmeter, I put the positive in the water and the ground to the ground of the 12 volt adapter. I was getting around 7 volts at 2 mA 
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I was getting around 7 volts at 2 mA 

How did you measure the current? 
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How are your connections to the coil? Underwater? Lol
and what does your multimeter say about resistance to ground and to the positive?
« Last Edit: June 12, 2012, 10:04:55 pm by winner10920 » Logged

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no the connections are not in the water and the path is about 41000 ohms
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12v/2ma is 6000 ohms so while the 41k isn't that great its odd your getting 2ma through the water
[Funny memory]Off topic a bit, this reminds me of a trick my dad played on his brother when he was young, he had a lightbulb (120v) lit underwater and asked his brother to unscrew it, which he tried lmao[/funny memory]

Obviously the wire isn't as insulated as you think, are the bubbles forming from one place or evenly throughout the whole coil? The other possibility is that the coil is loading the supply too much and the high switching speed current (assuming its a switching supply) is passing through the coil to the somehow grounded water like a capacitor
what is the supply measuring with the load on it? And do you have an oscilloscope you can probe around with?
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