hi it looks cool and it works!!!!!!!!!1

 

i've alrdy know about on this proj...the electrodes are the resistance coming from the tip of the finger...it neutralize how sweat is u'r skin...the more sweat, the more possibility means the person is not telling the truth...^^

 

You also might look into false positives and false negatives, test sensitivity and specificity, and Paul Ekman's book on lying.

Took a lie detector test once, and the tester lied to me about the results! I have observed that there is almost nothing that cannot be accomplished by lying.

You can detect lies, but finding the truth is a bit more difficult.

As to "other people", try this. . .
http://www.mcafee.cc/Bin/sb.html

 

Hi from Jerry.J.(Cape Town) Good to be with you guy's!I am 61 years old and wish you all of the best! Been in Electronics and radio.HT,Pic 16f84 for long time.Go for it!You are our future.I am also a radio ham,ZS1JJM and need a electronic drawing progam in order to be able to send you some of my Ideas.Can anybody help with a "ZIP"? Best to u all Jerry.J.My Email:jerryjean@vodamail.co.za

 

I make all my schematics with Microsoft Paint program.

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Uncle $crooge

 

I use LTspice, which is a simulator, but has a pretty good schematic capture.

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Ron

 

Same here, started with a lamp. Then advanced to a small motor, but would piss off the parents because the brush noise would screw up their TV reception, we were in a fringe area. Then advanced to crystal radios with a long wire antenna. Heathkits were great.

Lefty

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Measurement changes behavior

 

The things on the side of this guy's neck.
http://www.dmiblog.com/archives/Fran...is_Karloff.jpg

 

Even with high accuracy, this concept says you can still be lying, or not.
Sensitivity and specificity - Wikipedia, the free encyclopedia
It gets mathematical, with conditional probabilities.

The way around it is to take several lie-detector/pregnancy/other-medical tests.

I took a lie detector test once. The test-giver was lying to me about the results! (I didn't get the job, either. . .)

 

I use this as well, and although it's a little clumsy to use, you get used to it. I like the simulator, but I did find it strange that I put in a circuit for an isolated SM power supply, and it didn't like the isolation, making me earth the input (which is naughty in SM power supplier).

What's a good program for laying out PCBs? I used to use ezy tracks years ago, but haven't made one for many years.

 

You can generally earth a floating input through a huge resistor, such as 1e12 ohms (1 million megohms).

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Ron

 

electrodes is any material that allows electron to flow

 

It is really gr8......by tha way nice idea 4 tha next science fair....thnx

 

whats a 5K pot mean?? I know what a resistor is but whats a pot? The difference? Also do you need two 4.5V battery sources? What are those in the schematics?

 

A pot (short for potentiometer) is a resistor with a 3rd terminal (wiper) that is a variable tap. If you connect the wiper to one end of the resistor, you have a variable resistor, also known as a rheostat.
I posted an equivalent version of the original circuit that only uses one 9V battery on page 2 of this thread. I've attached it below.
You can use almost any general purpose NPN, such as 2N3904, etc.

Attached Thumbnails

 

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Ron