Martin C.'s build of the "4069 Brain Stimulator"
I've added a 1m ohm pot to the electrode because when I tested it with the multimeter and oscilloscope I
found out that the final output, at the electrode, was building up to 1200 millivolt!
So, there's a pot for the frequency (2hz to ultrasound), another one for the output level, and an on-off
switch. The electrodes are made of felt over a shim (0.006 inch thick) of
brass welded to the wire. I use standard "salinex" (salt water "nose cleaner").
Here's the little windows program I use to get an oscilloscope out of my pc, using the sound card.