Conversion of Mean Solar Time to Mean Sidereal Time

Autor:	J. Hers
Rok vydání:	1949
Předmět:	Physics Crystal Gear train Multidisciplinary Optics Continuous phase modulation business.industry Sidereal time Observatory Solar time business Quartz
Zdroj:	Nature. 164:841-841
ISSN:	1476-4687 0028-0836
DOI:	10.1038/164841a0
Popis:	OBSERVATORY practice in the past has always been to use separate clocks for indicating solar and sidereal time. In the case of quartz crystal clocks, this practice could be continued by using two separate crystals, one ground for a frequency of 100 kc./s. and the other for a frequency of 100·273 kc./s. It is, however, much more satisfactory to derive both solar and sidereal second pulses from one standard frequency oscillator. Hitherto, this has been accomplished by means of mechanical gearing, and many efforts have been made towards devising a gear train that would give a good approximation, and which would be mechanically practicable at the same time1. A different method is to use gears not for direct conversion, but to drive a continuous phase shifter, which has the effect of increasing one of the standard frequencies by 0·273 per cent2.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::941b5472bb7e0884411dba58107c16e9 https://doi.org/10.1038/164841a0 Zobrazit plný text záznamu