Solar and sidereal digital clock
Abstract
An integrated circuit digital clock was built which derives, from a temperature stabilized 100 kHz crystal oscillator, two time scales - solar and sidereal with indication of seconds, minutes and hours. Each time scale is displayed in binary code with 19 bits, by means of 5 columns of incandescent lamps with 1, 2, 4, 8 values as well as with remote dials and binary voltage levels. The sidereal second is derived from 100 kHz by means of a time varying frequency divider with alternate division ratios of 99727 and 99726 ensuring an accuracy better than 1 s per year. The entire system is fed from a continuously charged CdNi battery of 100 Ah capacity.
- Publication:
-
Studia Societatis Scientiarum Torunensis Sectio F Astronomia
- Pub Date:
- 1974
- Bibcode:
- 1974SSTor...5R...1G
- Keywords:
-
- Clocks;
- Digital Systems;
- Sidereal Time;
- Time Measurement;
- Universal Time;
- Astronomical Observatories;
- Crystal Oscillators;
- Instrument Errors;
- Integrated Circuits;
- Transistor Circuits;
- Instrumentation and Photography