My goal is to build something that simulates rapidity (50 to 1k Hz) pressing a key on a USB keyboard. My first inclination was drive a transistor from a 555 timer with the two keyboard matrix pins on the collector and emitter, unfortunately the potential between them is only 1.5dcv and the 2n3906 I have in my kit doesn't seem to work. Is this really a transistor problem or something else?
Also, I'm not looking for a keyboard emulator, I want something to test off the shelf keyboards. Any other ideas are welcome.
So I went out and got a NTE133, I was told it was the equiv to the BS138. The drain to source resistance was about 7Mohm and even when the 555 was off the signal from the keyboard went though. Did I get a dud? Schematic below 2hz, Picture below. I'm doing destructive testing on keyboards to measure timing, that's why I don't want to use the arduinos to simulate one.