diode, a. and n.
(ˈdaɪəʊd)
[mod.f. Gr. δι-, (di-2) twice, doubly + ὁδός way.]
A. adj. lit. Of two ways: applied by Mr. Preece to a mode of working, which converts a single telegraphic wire into two ways or ducts for signalling messages, without reference to direction; one application of the multiplex system of working.
| 1886 W. H. Preece in Jrnl. Soc. Teleg. Engineers XV. 231 A mode [of working] by which two messages are practically sent at the same time will be diode working. |
B. n. Electr. a. A thermionic valve of the simplest kind with just two electrodes, a cathode or ‘filament’ and an anode or ‘plate’. b. = semiconductor diode: cf. crystal diode (see crystal n. 9 d). Also attrib. or as adj.
| 1919 W. H. Eccles in Electrician 18 Apr. 475/2, I propose to give the name ‘diode’ to a tube with two electrodes. 1921 ― Contin. Wave Wireless Telegr. i. 257 A bulb with two electrodes, namely, anode and cathode, is called a diode tube. Ibid. 306 This example shows plainly that two constants are required to define the chief properties of a diode. 1929 J. A. Ratcliffe Physical Princ. Wireless ii. 23 The diode usually consists of a straight wire filament which is heated by an electric current. 1943 C. L. Boltz Basic Radio x. 154 The diode's only use is as a rectifier. By adding another electrode we can increase the utility of the valve. 1944 Electronic Engin. XVI. 408, C charges through a diode valve. 1955 [see crystal n. 9 d]. 1958 Times Rev. Industry July 29/1 Impurities in single crystals in connexion with the production of transistors and diodes. 1959 K. Henney Radio Engin. Handbk. (ed. 5) ix. 7 Logic circuits using diodes may be considered another class of switching applications. 1970 D. F. Shaw Introd. Electronics (ed. 2) xi. 226 The rectifying property of a semi-conductor diode is a consequence of the asymmetrical conduction across the contact between a metal and a semi-conductor. |
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Add: [B.] c. Special Comb. diode-transistor logic n. Electronics, logic in which diodes rather than resistors form the coupling elements between transistors.
| [1957 Wescon Convention Rec. IRE ii. 3 Both of these designs can be derived..by the substitution of diode-transistor logical equivalents for the series and parallel combinations of transistors of DCTL. 1959 Ann. Computation Lab. Harvard Univ. XXX. 170 A type of transistor-diode logic circuit design.] 1960 IRE Trans. Electronic Computers IX. 16/2 Resistor-transistor logic, though simple and reliable in a component sense, is slower than diode-transistor logic. 1987 Millman & Grabel Microelectronics (ed. 2) vi. 219 This gate realization is called diode-transistor logic (DTL) and was one of the early semiconductor logic families developed. |