View single post by Dr. Heinz Doofenshmirtz
 Posted: Mar 7th, 2015 06:53 PM
PM Quote Reply Full Topic
Dr. Heinz Doofenshmirtz



Joined: Nov 17th, 2013
Location: Liberty, Missouri USA
Posts: 300
Status: 
Offline
I have started seeing devices said to be able to detect "static electricity". Most of the units I have seen have been fairly inexpensive. Anyways........ If you want to give it a shot.  It's pretty simple. The unit consists of a LM7805 voltage regulator and a CD4017 decade counter,  two resistors, two LEDs, and a two electrolytic caps for the power supply. Basically just start with the voltage regulator to get your 5v for the 4017, wire power and ground to the 4017. Alternate outputs on the 4017 to the LED/resistor, and use a small length of solid copper wire hooked up to the clock input of the 4017, for an antenna. Hook your last output back into the reset and you are done. Rub a balloon on in your hair or on a wool sweater, you will see that the movement of the static field around the antenna causes the 4017 to clock to the next output quite fast, resulting in blinking LEDs. The antenna length determines the sensitivity of the circuit. Too long and it will twitch with no external field presence.

Edit: Actually don't hook up output 9 to the LED, as the other outputs connected will reset the chip.

Attached Image (viewed 130 times):

20150307_123022.jpg

Last edited on Mar 7th, 2015 07:21 PM by Dr. Heinz Doofenshmirtz