a thermionic tube having two electrodes; used as a rectifier
"The vintage radio repair manual warned that replacing the old vacuum diode, which served as both a thermionic tube and a rectifier, required finding an exact match for its two-electrode design."
a semiconductor that consists of a p-n junction
"The technician replaced the faulty component, which is a semiconductor consisting of a p-n junction used to convert alternating current into direct current."
An electronic device that allows current to flow in one direction only; used chiefly as a rectifier.
"The technician replaced the faulty diode in the power supply, which restored the proper one-way flow of electricity needed for the circuit to function correctly."