Simple Lie Detector


Author Views Views Today Rank Comments
192,556 156 276
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.

Related Circuits

Air Flow Detector, Wire Loop Alarm, Simple Two Speed Contactor DC Motor Controller , 7 Segment LED Counter, Simple Lie Detector, Low Voltage Alarm, Video Stabilizer/MacroVision Removal, Pulse Width Modulation DC Motor Control, Simple Polarity Tester, Pine Racecar Victory Judge, Rain Detector, Time Delay Relay, Time Delay Relay II, Stepper Motor Controller, Touch Switch, Video Activated Relay, Digital Keypad Combination Lock, AC Motor Speed Controller, Simple Servo Controller, Water Detector With Sump/Bilge Pump Controller

Comments

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.)

anonymous
Simple Lie Detector
Saturday, April 18, 2009 12:46:05 PM
does it work.has anyone tried it?
anonymous
Simple Lie Detector
Friday, March 13, 2009 2:19:17 AM
want to kno how to make it? where it has to connect? is it pain ful or not? any chances to get electrical shock when it connected to the body? is it make any problem to the inner organs?
Deb
Simple Lie Detector
Sunday, March 08, 2009 5:43:18 AM
Hi there can you put pictures of the result of a built Simple Lie Detector, what it looks like in detail step by step results till the time it gets completed.
salma
Simple Lie Detector
Saturday, March 07, 2009 2:55:49 AM
thank you I think it will be amazing project when i try to design it
yaya
Simple Lie Detector
Wednesday, February 25, 2009 7:29:32 PM
the stuffs seems expensive... how much does the whole thing cost??
anonymous
Simple Lie Detector
Thursday, February 12, 2009 4:52:36 AM
i want to know that when probes are connected to hand does it effect any organ or whether there is an electric shock
The last 10 comments are currently shown. Show All Comments.

If you would like to leave a comment, you can do so using the form below. Comments can be things like suggestions, successes or failures, improvements, similar circuits, error reports, an answer to a previous commenter's question, or anything in between. However if you would like to ask a question it is suggested that you use the forum instead. The forum provides a more robust environment for discussion.

Important: If you post a technical question here, there is no guarantee it will be answered. All technical questions should be posted to the forum. The owner of this site generally does not answer questions in comments.

All comments are subject to approval before they are displayed here, so your comment will not appear immediately. This is done mainly to prevent spam and other abuse. If you wish to remain anonymous, simply enter "anonymous" for your name and/or email.

Name:
Email:
Subject:
Comments:
Anti Spam Code:
Please enter the exact text shown in the image above into the box below.
Browser cookies must be enabled to comment on circuits.

Privacy Policy

Back To Circuits Page | Mail Me | Search