"Robot" was first coined by playwright Karel Capek in 1921 for the play R.U.R. (Rossum's Universal Robots). "Robot" is Czech for drudgery or slave labor. Later, used by Issac Asimov in a short story, "I, Robot ".
Adjustable 100 K resistor has solid weighted pendulum attached to shaft of resistor and is calm at output on level floor. Swings from out of balance send positive output to circuits you want to take action to level robot. Lamp below 100 k resistor above represents shaft with swinging weight sending level information into circuit.
Two circuits would be needed for front to back and right to left.
Parts are LM339 IC and diodes are 1N914.
