| 释义 |
saw tooth
[saw n.1]
1. a. A tooth of a saw. b. A tooth (of an animal, also, of a machine) shaped like a saw, or forming one of a serrated series.
1601Holland Pliny I. 337 The saw teeth run one betweene another,..as we see in serpents, fishes, and dogs. 1835Ure Philos. Manuf. 113 The saw-teeth of the gin, in tearing the fibres from the seeds, broke several of them. 1880Bale Woodworking Machinery 332 A circular holder..fitted to a circular notch at the root of the saw tooth. 1886Encycl. Brit. XXI. 344/1 Inserted teeth [in circular saws] are of various forms and shapes, from that of the ordinary saw tooth..to a ‘chisel point’.
c. Electronics. A wave-form showing a slow linear rise and rapid linear fall, or the reverse; a voltage or current varying in this way. Usu. attrib., as saw-tooth generator, saw tooth wave-form.
1933Proc. IRE XXI. 1666 The variation of intensity of both horizontal and vertical deflecting fields plotted against time is of a ‘saw-tooth’ shape. 1935M. G. Scroggie Television iv. 37 The sudden charge of the condenser, followed by a slower discharge, yields a saw-tooth wave-form. 1940[see keystone v.]. 1942Electronic Engin. XIV. 666/2 The time-base circuit is..adapted for single sweep operation and the saw-tooth generated can be expanded symmetrically with respect to the centre of the tube. 1947R. Lee Electronic Transformers & Circuits ix. 251 Probably the most common application of sawtooth amplifier transformers is to provide a linear sweep to horizontal plates of a cathode ray oscilloscope. 1969J. J. Sparkes Transistor Switching iii. 63 All sawtooth-wave generators integrate a constant voltage or current with respect to time.
2. attrib. = saw-toothed. saw-tooth roof, a roof with a serrated profile incorporating windows in the steeper sides, which face in the direction of the equator; saw-tooth sterrinck, the Crab-eating Seal, Lobodon carcinophaga.
187.Cassell's Nat. Hist. II. 243 The Crab-eating Seal or Saw-tooth Sterrinck of Owen [cf. saw-toothed 1866 in saw n.1 5]. 1884W. S. B. McLaren Spinning (ed. 2) 228 All of which are covered with garnet saw-tooth licker-in wire. 1900Engineering 9 Feb. 173/2 The factory consists of four bays, each covered with a saw-tooth roof running east and west, and glazed on the north side only. 1942Asher & Heal Send no Money 58 It had plenty of windows, a sawtooth roof to provide light, and it was airy and spacious. 1966L. Cohen Beautiful Losers i. 10 The sun was just coming up over the sawtooth roof of the factory next door. |