How to Make a Portable Handy Lie Detector in Altoid Tin




Introduction: How to Make a Portable Handy Lie Detector in Altoid Tin

Hi. I'm paewookyung, and this is my first posting in this site. please take note that
english is not my mother tongue. so please understand some of my gramatic mistake.;

Anyway, let's get this started!
This is a portable lie-detector built in Altiod tin. maybe you could have some fun useing this thing.

note: this detector is less sensitive then a real one. this could be miss some (many) of the lies.

Step 1: Things You'll Need.

You will need some things below for this project.

1. circuit board
2. 10K& resister
3. 47K& resister
4. 470& resister
5. 1M& resister x2
6. 47K& VR
7. knob for VR
8. 2N3904 transistor x3
9. 0.1 ? mylar cap
10. slide switch.
11. 9V bettery snap
12. LED (one red, one green)
13. solding tools.
14. drill
15. basic tools,
16. valcro
17. aluminum foil
....and most of all, Altoid tin!

Step 2: Make a Finger Pads

make a finger pads by sticking a aluminum foil to the valcro.
And don' forget to stick a wire between the valcro and thw foil!

Step 3: Solding the Circuit

Solder the circuit as a diagram below. And before solding the circuit, cut the circuit board to

suitable size to fit in the Altoid tin

Step 4: Drilling the Altoid Tin

Drill the Altoid tin for a VR.

and DO NOT use a sharp-end drill bit. it will tear the tin into half.

Step 5: Put the Floor Sheet

Put the floor sheet in a floor of the tin to avoid circuit from 'shorting'.

and secure is with a glue.

in my case, I used a piece of box, and secure with a hotmelt.

Step 6: Put Everything in Order.

Put everything in a Altoid tin and secure all of them with a glue, hotmelt, E.T.C

Step 7: Done.

Now your lie detector is ready to go. first, put the finger pad to the finger of the 'suspect'
then, slowly, turn the VR until the 'true' LED is light, and the 'false' LED is dark.
then, ask a question to the suspect , when the false LED get light, the suspect is lying.

Step 8: Enjoy!

Just Enjoy that detector. but take this in your mind, this may not be detect lie so perfectly.

And sorry about mistake the 'welcome' to 'walcome' is the photos.

So...have fun.....



  • Tiny Home Contest

    Tiny Home Contest
  • Fix It! Contest

    Fix It! Contest
  • Creative Misuse Contest

    Creative Misuse Contest

185 Discussions

Where did you get the circuit board?

Huh. I think it may be an engineering or hardware store. But I am not entirely sure about that. Maybe you should consult a STEM (Science, Engineering, Math, Technology) site, such as the ScienceBuddy forum, which will hopefully clear things up. Best of Luck. Also, see my post above, if it's no trouble.

How does this lie detector actually detect lies? Meaning, how can it tell if you are telling a lie or not? Just wanted to get a doubt clarified. Your project is very interesting and creative.


1 year ago

Where did you by the 47k variable resistor with numbered knob

2 replies

1 year ago

what does vr stand for in this project in send him an email but he did not respond and i want to make this for my science fair

4 replies

No VR stands for Virtual Reality!!!!!


sir? can you post the detailed circuit? because i already choose it to be my functional demo model? reply ASAP sir

can anyone please tell me how it will sense lies with skin it would require a sensor and code to tell if the person is twlling the truth or lying


1 year ago

when i made this the red led did not light up why?

if i move my hand or body it will sometimes go red. if i touch them both together then it will go to red then back to green if i let go. so I am I close to getting it to work. Like I said could not get all the parts, I do have two of the green leds that are at 2 volts. may have to try this. and I think the project is so in a week or so, Help

I used a 100k VR and one of my led (green) is 3v and the red is 12 volts.I could not get the right stuff, is this why it is not working