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.


This is the schematic of the Lie Detector


Total Qty.
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)


  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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Simple Lie Detector-RE: person requesting how to video...
Friday, September 04, 2015 4:55:20 PM
To the person asking that a "how to build this" video be sent to him: (prince-something was username)... Dude, if you cant build THIS circuit, (which by the schematic you could almost thumb-twist together) maybe you should consider NOT going anywhere NEAR ELECTRONICS, OR ANYWHERE you could hurt yourself or others... In other words, ask George to tell you about the rabbits..! And dont leave home without wearing your helmet!!
Simple Lie Detector
Sunday, February 08, 2015 5:19:29 AM
can we use digital meter in place of analog???
prince coffie
Simple Lie Detector
Sunday, September 28, 2014 9:52:11 AM
please am finding it difficult to build this circuit and i need your help by sending me a video tutorial of how to build the simple lie detector.hope my request will meet your kindest consederation
md zarif
Simple Lie Detector
Saturday, March 22, 2014 1:09:44 AM
yes, this is the really very nice project and i made also.. its working bindas....
Simple Lie Detector
Monday, September 09, 2013 12:59:02 AM
Dear Sir or Ma'am, I would like to ask if the pointer of the analog meter goes down when somebody lies or is my analog meter the problem? Also, when it is being tested, does the meter have to move from 0 then so on or from any number as long as it moves then it is lying? please reply asap. i need thisproject two days from now :(
Simple Lie Detector
Thursday, November 22, 2012 10:58:06 AM
is this really works if yes plz mail me back coz i wana do this project
Simple Lie Detector
Tuesday, November 06, 2012 2:03:46 PM
I want to ask about how does analog meter works in dis lie detector??
Simple Lie Detector
Friday, August 24, 2012 7:29:13 AM
Simple Lie Detector
Friday, August 24, 2012 7:26:01 AM
i am a BTECH 3rd year student .i want to submit this project in my college as a minor project so please give me it's complete information project report and pdf file .please send as early as possible we have a limited time.thank u ..................
Simple Lie Detector
Monday, August 06, 2012 4:00:21 AM
AHEM. Professional lie detection examiner specified "ask yes or no questions only" by preparing brackets (sets) of questions ahead of time
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