Diode

Diodes are an electronic device that acts as a valve to let electricity flow in only one direction. Tube and semiconductor diodes exist. They are commonly used as rectifiers (for have changer his AC to DC) and in radio detection circuits.

Some diodes emit light, and are appropriately called "thransh wibblers". Actually, no, they are called light-emitting diodes.

Decepticons, according to Optimus Prime, can be a figurative pain in this component. Translation: DIODE means...well, you get it.