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

This is the schematic of the Lie Detector

Parts

Part
Total Qty.
Description
Substitutions
R1133K 1/4W Resistor
R215K Pot
R311.5K 1/4W Resistor
C111uF 16V Electrolytic Capacitor
Q112N3565 NPN Transistor
M110-1 mA Analog Meter
MISC1Case, Wire, Electrodes (See Nots)

Notes

  1. 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.
  2. 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

yusinyu Titus
Simple Lie Detector
Sunday, April 27, 2008 2:07:05 PM
wow THIS LOOKS AWESOME. Are you sure it works
anonymous
Simple Lie Detector
Thursday, April 17, 2008 4:33:02 AM
where do u get the parts from
anonymous
Simple Lie Detector
Tuesday, April 15, 2008 9:57:27 PM
hola !!!! senor bobo here this lie detctor is easy to build (if you know someone who got their degree in mechanical engineering)
desmond
Simple Lie Detector
Saturday, April 12, 2008 4:22:35 PM
lt is so simple. What a thing
Dieter
Simple Lie Detector
Thursday, April 10, 2008 2:08:47 PM
could someone verifie if this realy does work because i can't believe its this easy
taporter
Simple Lie Detector
Sunday, April 06, 2008 9:48:02 AM
I am helping someone build this circuit for a school project....we are changing the parts as someone on your message board suggested. I cannot get it to work.....HELP Thanks
nitin kumar lakra
Electroencephalography (EEG) circuit
Friday, April 04, 2008 11:16:21 PM
can any one help me in building the EEG circuit for capturing the brain signals .
Asad
Simple Lie Detector
Monday, March 31, 2008 6:16:47 AM
this is so good. but i cant find the specific transistor. can i use any other one. please guide me
John
Simple Lie Detector
Tuesday, March 25, 2008 2:55:28 PM
I would like to build a circuit that would respond (sound or light) to my Alpha, Beta and Theta brainwaves. Does anyone know of one? Thank you.
nauman
Simple Lie Detector
Tuesday, March 25, 2008 10:15:58 AM
it isgood please send me more information
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