| 释义 |
keep-alive, a. Electronics.|ˈkiːpəlaɪv|
[f. to keep alive (keep v. 24).]
Applied to devices and phenomena in certain kinds of discharge tube which operate or occur continuously and serve to initiate an intermittent main discharge or facilitate its establishment. Also ellipt., such a device or phenomenon.
1933J. H. Morecroft Electron Tubes viii. 182 In large bulbs a ‘keep-alive’ circuit is used to maintain the ionization. 1947A. E. Whitford in L. N. Ridenour Radar Syst. Engin. xi. 410 To insure rapid breakdown at the beginning of each pulse, a supply of ions in the gap is maintained by a continuous auxiliary discharge inside one of the cones. This requires an extra electrode, known as the ‘keep-alive’ electrode. 1947Crowther & Whiddington Science at War i. 47 The final form was a cavity..with a small pilot discharge or ‘keep alive’ to help the gas discharge to start. 1959R. L. Shrader Electronic Communication xxix. 842 To make the TR tube more sensitive, a d-c keep-alive voltage is applied across it at all times. This voltage is not quite high enough to support ionization. 1965Gewartowski & Watson Princ. Electron Tubes xv. 554 Tubes in which radioactive material has been placed for the purpose of obtaining short ionizaion times are said to have a radioactive keep-alive. Ibid., In some tubes a low-current discharge between auxiliary electrodes is operated continuously as a keep-alive mechanism. |