Who stole the cookies from the cookie jar? You don’t need to go down to the police station to make the suspects take a polygraph test. If you hook up this truth meter circuit, you can find the culprit by measuring their galvanic skin response.
Galvanic skin response (GSR), which is actually a main component of traditional polygraph tests, is basically skin conductance. When you get hopped up on adrenaline or similar hormones, your skin releases micro-beads of sweat. The sweat raises your skin’s electrical conductance, which can be measured... and used to tell if someone’s not quite truthful, in case you’re in the mood for a game of good cop/bad cop.
This article is part of a wiki anyone can edit. If you have advice to add, please log in and contribute.
Insulated 18 gauge wire, cut into two 10-inch pieces 1-inch wide, .005-inch thin copper or brass foil, 6-inches long ¾-inch Velcro tape, 7-inches long 1/4W resistors: 220 Ohm, 10 kOhm, 100kOhm, 1MOhm, 3.3MOhm (2) Capacitors: 10 nF, .1micro F (2)Cut the soft (loop) side of the Velcro in half, and cut two ¾-inch squares of the rough Velcro. Cut the brass foil in half. Strip about half an inch off of one end of each piece of wire.
Remove the backing from the Velcro pieces. Stick the rough Velcro square back-to-back onto one end of the smooth strip. Lay the wire about ¾-inches from the opposite end of the smooth Velcro so that the stripped section is poking out the top. Peel the backing off the copper foil and lay it on top of the smooth velcro’s sticky backing, cutting to remove any excess.
After you’ve created these two sensors, you can strip about ¼-inch off the other ends of the wires and either tin them or solder them to the 2-pin headers.
Assemble the circuit in the diagram.
For the op-amp’s pin assignments, check out the data sheet under “Helpful Links.”
Before hooking up your assembled circuit to your battery power supply, be sure to double check your circuit -- it can be easy to accidentally use one resistor in place of another, or leave out an important connection. Once you’ve got everything correctly in place, you can snip off the extra wire on your components so your finished circuit looks cleaner.
Wrap each velcro sensor around a finger, and start trying your circuit out! The LED should light up one to two seconds after you lie, laugh, or experience another emotional stimulus.
Biosensor Array Galvanic Skin Response
This page was last modified 08:13, 22 July 2011 by howto_admin.
View the original article here
This post was made using the Auto Blogging Software from WebMagnates.org This line will not appear when posts are made after activating the software to full version.
No comments:
Post a Comment