Lie detector with shock

[yankos243]

I am going to build a lie detector with shocking effect when a person is lying. This is to be my senior project as i am a senior electrial engineer. This is going to be my first serious project and need help. I have the basic concept down, im going to monitor skin resistance and pulse with the ciruit. i have been researching other projects similar but i dont want to use their designs. I am looking for the self satisfaction of i built that with my own designs. How would i get started going about that. i have a whole year to build so i will be back time to time asking questions and telling my results.

Thanks guys for all the help.

 

[chipi]

hi . i think start with building a quality supply as your circuit is going to be very sensitive cud end up wi face like this for telling truth . is it going to be batt or ac ?

 

[audioguru]

I looked at Lie Detectors in Google.
How Stuff Works explains that the many sensors need to be monitored by an expert and even then, the resuslts are about the same as flipping a coin.

Some people sweat and show stress when they are just thinking about having a lie detector test. Some people are normal when they tell a lie.

 

[TrevorP]

I looked at Lie Detectors in Google.
How Stuff Works explains that the many sensors need to be monitored by an expert and even then, the resuslts are about the same as flipping a coin.

Some people sweat and show stress when they are just thinking about having a lie detector test. Some people are normal when they tell a lie.

Yeah and keep in mind if someone tells themselves something enough they can pretty much believe it enough that it won't show up.

Ummm...wouldn't the shock make another shock happen? so basically the person would always be shocked?

 

[Hero999]

Ask on a few forums and Google until someone hands you a goos lie detector design on a plate and built the circui. Now you're ready to demonstate it to your lecturer, connect it up to yourself and get them to ask you if the project was all your own work and prepare to be shocked.

No, seriously, I'd recopmmend a different project. Good lie detectors are hard to build and even then aren't 100% accurate and as there's a shock involved you have a high chance of shocking an innocent person.

Then there's the question of how bad you want the shock to be, I take it you don't want it to execute the person who it deems to be lying. Getting the level of shock to be painful but not deadly or even damaging can be a very difficult thing to do.

Go for something more useful that might be able to help you later on like a programmable signal generator or an LRC network analyser.

 

[wejos]

lol this is hilarious gzzzzt!!!

 

[HarveyH42]

You know that you would need to calibrate this to each individual, and shock them a few times during the setup. You would need to establish what is normal, what constitutes a lie, and what is the response to being shocked. I hate getting shocked, so I would be fairly stressed out, and anxious. It would be tough to establish a baseline to work from. I'm sure you would want some sort of timer, to prevent repeated shocks when the victim responds to the initial jolt. I doubt that the subject will return to a baseline state, once getting zapped.

Somehow, I can't believe this is for any serious application (maybe interrogation, since Water-boarding has been banned), so figure it must be more of a novelty/gag project, where the truth isn't critical, just shocking the subject for amusement. Most lie detectors measure stress, which will increase with every shock. You'll need to compensate for these changes.

 

[gabeNC]

This request/topic comes up quite a bit.

google search site:Electronic Circuits Projects Diagrams Schematics Electronics Circuit Project "lie detector"
Results 1 - 10 of about 192 from Electronic Circuits Projects Diagrams Schematics Electronics Circuit Project for "lie detector".

 

[HarveyH42]

You know that you would need to calibrate this to each individual, and shock them a few times during the setup. You would need to establish what is normal, what constitutes a lie, and what is the response to being shocked. I hate getting shocked, so I would be fairly stressed out, and anxious. It would be tough to establish a baseline to work from. I'm sure you would want some sort of timer, to prevent repeated shocks when the victim responds to the initial jolt. I doubt that the subject will return to a baseline state, once getting zapped.

Somehow, I can't believe this is for any serious application (maybe interrogation, since Water-boarding has been banned), so figure it must be more of a novelty/gag project, where the truth isn't critical, just shocking the subject for amusement. Most lie detectors measure stress, which will increase with every shock. You'll need to compensate for these changes.