Magnetic Experiment Confirmed!

[PaulLowrance]

The thinnest paper I had was a cigarette paper the results were very poor nearly as bad as the banknote.
I found this video on YouTube, was this the one you were looking for Paul ?
Apparently there is already a thread on this topic but I can't find it anywhere on the fourm
http://www.youtube.com/watch?v=3mX8S767zT4&NR=1
cat

That's a different video.

I think the main reason the leaf showed more voltage on your meter was because the leaf has lower resistance, which means your meter will not shunt the voltage as much.

Maybe you could find the input resistance of your voltage meter. If it's at least 10Mohms, then you could place a 10uF capacitor (low leakage is highly recommended), then give it awhile to charge, and then measure the voltage across the capacitor with your meter. The amount of time require to allow the capacitor to charge depends on the insulation resistance of whatever is between the magnet and washer.


Regards,
Paul

[teslaalset]

I tried to replicate this effect but failed to measure larger than 0 volt.
My digital multimeter may not be that high resistant as Paul's or Cat's.
I'll try the experiment with the capacitor.

B.t.w. I calculated the capacitor situation : 1 uF in 5 minutes to 600 mV: that gives you 2 nA load current, apart from the leakage resistance that an electrolyte capacitor has.

[PaulLowrance]

teslaalset,

What did you use as an insulator? If you use something like paper or even wax paper then you might get at least a few millivolts.

... wait a minute. My meter when in 20Mohm Rin mode got 35mV, but some meters have only 1 to 2 Mohms Rin. One of my harbor freight meters is like 1Mohm. In that case, you should get a bit over 1mV. So maybe your insulation has to much resistance.

... Or maybe your metal washer is different. What kind of metal are you using? What type of magnet?

Thanks,
Paul

[powercat]

That's a different video.

I think the main reason the leaf showed more voltage on your meter was because the leaf has lower resistance, which means your meter will not shunt the voltage as much.

Maybe you could find the input resistance of your voltage meter. If it's at least 10Mohms, then you could place a 10uF capacitor (low leakage is highly recommended), then give it awhile to charge, and then measure the voltage across the capacitor with your meter. The amount of time require to allow the capacitor to charge depends on the insulation resistance of whatever is between the magnet and washer.


Regards,
Paul

My meter is 10MΩ  But I am going to have to search through my old electric junk for a 10uF
cat

[PaulLowrance]

This is a good RC time constant online tool,

http://www.cvs1.uklinux.net/cgi-bin/calculators/time_const.cgi

Plugging in 10Mohm & 10uF & 3 seconds gives 3% decay which is good. That means every 3 seconds the 10Mohm meter will drain the 10uF cap 3%.

You could probably get away with a 2uF cap, which drains 14% per 3 seconds. It might take a long time to charge the 10uF cap.

Paul