Simple Lie Detector

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Here's a simple lie detector that can be built in a few minutes, but can be incredibly useful when you want to know if someone is really telling you the truth. It is not as sophisticated as the ones the professionals use, but it works. It works by measuring skin resistance, which goes down when you lie.

Schematic

Parts

Part	Total Qty.	Description	Substitutions
R1	1	33K 1/4W Resistor
R2	1	5K Pot
R3	1	1.5K 1/4W Resistor
C1	1	1uF 16V Electrolytic Capacitor
Q1	1	2N3565 NPN Transistor
M1	1	0-1 mA Analog Meter
MISC	1	Case, Wire, Electrodes (See Nots)

Notes

The electrodes can be alligator clips (although they can be painful), electrode pads (like the type they use in the hospital), or just wires and tape.

To use the circuit, attach the electrodes to the back of the subjects hand, about 1 inch apart. Then, adjust the meter for a reading of 0. Ask the questions. You know the subject is lying when the meter changes.

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Comments

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Zeaga Re: how does it work? Thursday, August 20, 2009 4:31:11 AM

It works by recording your blood pressure, heart rate, and sweating.

ketaki Simple Lie Detector Wednesday, August 05, 2009 7:58:19 AM

it is such a nice project but i want to know it's working .i want to build this.the alligator clips used in this,are they very painful.please give me answers as early as possible.

three musketers Simple Lie Detector Sunday, August 02, 2009 3:10:40 AM

wow!amazing!we want to try!!!! I think it will help us do our science investigatory project!!!!

lasya Simple Lie Detector Tuesday, July 21, 2009 8:57:30 AM

can u explain about the disadvantages by useing lie detectors ara really effective..........?

SakthiRaj Simple Lie Detector Saturday, June 27, 2009 9:49:18 PM

Its just a simple and effective project.But can i able to know how to assemble the project with picture presentation.

agboola sunday Simple Lie Detector Friday, June 19, 2009 5:44:56 AM

it will be great if the circiut is efficient

ROCKY Simple Lie Detector Thursday, May 14, 2009 2:50:08 AM

no question about the simplicity.but is it accurate

anonymous human lie detection Wednesday, May 06, 2009 7:34:08 PM

Why go through the trouble of making a lie detector? Their are plenty of resources out their to help you catch liars by certain techniques. Check out www.humanliedetection.com it has a bunch of different techniques you can use. It is a much better alternative then actually hooking someone up to a lie detector.

anonymous Simple Lie Detector Monday, May 04, 2009 5:08:33 PM

it doesnt work it's a load of bullshit

Phoebe how does it work? Monday, May 04, 2009 10:06:46 AM

I would like to know how a lie detector works because i have no idea if they work or not, some people say that its skin resistance and some people say that it works by your blood presure???
(Editor's notes: This works on skin resistance.)

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Zeaga	Re: how does it work?	Thursday, August 20, 2009 4:31:11 AM
It works by recording your blood pressure, heart rate, and sweating.
ketaki	Simple Lie Detector	Wednesday, August 05, 2009 7:58:19 AM
it is such a nice project but i want to know it's working .i want to build this.the alligator clips used in this,are they very painful.please give me answers as early as possible.
three musketers	Simple Lie Detector	Sunday, August 02, 2009 3:10:40 AM
wow!amazing!we want to try!!!! I think it will help us do our science investigatory project!!!!
lasya	Simple Lie Detector	Tuesday, July 21, 2009 8:57:30 AM
can u explain about the disadvantages by useing lie detectors ara really effective..........?
SakthiRaj	Simple Lie Detector	Saturday, June 27, 2009 9:49:18 PM
Its just a simple and effective project.But can i able to know how to assemble the project with picture presentation.
agboola sunday	Simple Lie Detector	Friday, June 19, 2009 5:44:56 AM
it will be great if the circiut is efficient
ROCKY	Simple Lie Detector	Thursday, May 14, 2009 2:50:08 AM
no question about the simplicity.but is it accurate
anonymous	human lie detection	Wednesday, May 06, 2009 7:34:08 PM
Why go through the trouble of making a lie detector? Their are plenty of resources out their to help you catch liars by certain techniques. Check out www.humanliedetection.com it has a bunch of different techniques you can use. It is a much better alternative then actually hooking someone up to a lie detector.
anonymous	Simple Lie Detector	Monday, May 04, 2009 5:08:33 PM
it doesnt work it's a load of bullshit
Phoebe	how does it work?	Monday, May 04, 2009 10:06:46 AM
I would like to know how a lie detector works because i have no idea if they work or not, some people say that its skin resistance and some people say that it works by your blood presure??? (Editor's notes: This works on skin resistance.)