R2 5k pot
C1 1uF 16v electrolytic capacitor
Q1 2N3565 NPN transistor
M1 0-1mA analog meter
- 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.
- 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.