it just measures/ shows the variation in the skin resistance(aka galvanic skin resistance) .when we lie , biological changes occur in our causes perspiration , so that the skin resistance goes low .
Here's a simple lie detector that can be built in a few minutes, but can be incredibly useful when you want to know if someone is really telling you the truth. It is not as sophisticated as the ones the professionals use, but it works. It works by measuring skin resistance, which goes down when you lie.
hi.i hav made this project but i hav used power transistor BD115 instead of 2N3565.Can u tell me whether it is ok or not and if not please tell me the transistor as 2N3565 is not available in the market
hi.i hav made this project but i hav used power transistor BD115 instead of 2N3565.Can u tell me whether it is ok or not and if not please tell me the transistor as 2N3565 is not available in the market
The electrodes are the parts of the circuit that touches your skin for the circuit to measure the resistance.
Electrodes are usually made from rotting dead fish, aren't they?
Thanks for giving this valuable and simpe circuit. But I am unable to get this transistor . Can u think this will work with any other transistor like BC 548 or simply tell me about the equivalent. Thanks again...
Made the circuit ...it's quite a nice gadget :lol.I used something like 0.5X2.5 inches strips of metal (Al) with tape as electrods. I used a 2n4401 transistor.
I already cought my girlfriend lying :lol.
Just wanted to know why exactly there are two power supplies in the lie detector circuit as opposed to one - what is the function in relation to how this circuit works?
Just wanted to know why exactly there are two power supplies in the lie detector circuit as opposed to one - what is the function in relation to how this circuit works?
Thanks for the reply, Ron - I like your schematic alot. My class will be building these and your version will allow us to have smaller groups working on this since we will now have more power supplies to work with. I see how your particular circuit can be re-drawn to essentially be a wheatstone bridge circuit. However, I am still a bit stuck on how the original circuit can be represented this way with those two power supplies. Why did the designer feel that two power supplies were needed in this circuit?