This instructable shows how to build a static detector. I have built several robots, and one problem that I often encounter is a static buildup/discharge that causes interferences with the motor controllers. The hardest thing about this problem is that it is difficult to test the static buildup to see what type of solution is necessary. Because of this I have built a basic static detector. This will indicate with an LED a difference in static charge.
Step 1: The Circuit
The circuit uses three NPN transistors to detect a static charge, and turn on or off an LED accordingly. I used a 1M ohm potentiometer as a sensitivity adjustment knob.
Step 2: The Case
I 3d printed the case; the file can be found at http://www.thingiverse.com/thing:823499 . I also included an on/off switch(not in the schematic) the circuit runs on 6 volts, so I made a compartment for two 3v batteries using two plates salvaged from an old battery holder. They fit into a depression in the 3d printed case and can be soldered to the circuit.