Make your own real-working lie detector. Provide yourself or others a great learning experience with a kit ideal for beginners or experimenters.This kit contains a paper circuit board template. This paper circuit board is used in place of a real circuit board, so there is no need to solder. You only need to twist your connections together.
The kit contains:
- 1 - 82KΩ resistor
- 1 - 4.7KΩ resistor
- 1 - 3906 transistor
- 1 - 3904 transistor
- 1 - .01 mfd ceramic disk capacitor
- 1 - 9 volt battery clip
- 1 - 8 Ω speaker
- 3 - 18 gauge solid wire (stripped and cut to length)
- 2 - alligator jumper cables
- 1 - circuit board template
- 2 - paper clips
This kit provides you with everything you will need except for a 9 volt battery and the project enclosure. Have some fun building or designing the project enclosure. In the past I've used a dollar store pencil box, a cigar box, a cardboard box, or a Mr. Potato Head.
This simple, sound-producing circuit is a perfect for anyone looking to experiment. The same circuit can be used to make many different alarms and musical devices. See www.deweymac.com for more details.
The lie detector works on a principle called galvanic skin response. Basically, it detects sweat, which usually happens when someone lies. Sweat increases the conductivity (ability to let electricity pass through) of your skin. Your sympathetic nervous system controls the sweat glands on your fingertips and is completely subconscious (not controlled by you). When caught in a lie, these fight-or-flight nerves are alerted. Your body will sweat a little. The sweat will cause the electricity to flow in higher amounts and produce a higher pitched sound from the Interrogator 3000.