JPS5529730A - Frequency source switching unit of digital watch - Google Patents
Frequency source switching unit of digital watchInfo
- Publication number
- JPS5529730A JPS5529730A JP10219578A JP10219578A JPS5529730A JP S5529730 A JPS5529730 A JP S5529730A JP 10219578 A JP10219578 A JP 10219578A JP 10219578 A JP10219578 A JP 10219578A JP S5529730 A JPS5529730 A JP S5529730A
- Authority
- JP
- Japan
- Prior art keywords
- signals
- time
- frequency
- counter
- output
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Electric Clocks (AREA)
- Electronic Switches (AREA)
Abstract
PURPOSE: To make it possible to continue automatically the time counting operation at a power failure time by performing the time counting operation by binary signals in one period of the commercial frequency and switching them to signals from an internal oscillator circuit for the time counting operation when binary signals do not exist.
CONSTITUTION: At a normal time, commercial frequency signals shaped by 22 are read into static shift register 23 by clock pulse CK of control pulse generation circuit 35 where two or more pulses are included in the positive side of the signal; and while defining the output of NAND circuit 29 as "1", commercial frequency signals are used as reference signals of time counter 33. At a power failure time, signals from oscillator operated by a battery are frequency-divided to 50 Hz by 30 and are applied to time counter 33 while defining the output of NAND circuit 29 as "0", and simultaneously, counter 33 is switched to a counter matching to a prescribed frequency by the output of frequency switching gate 40.
COPYRIGHT: (C)1980,JPO&Japio
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10219578A JPS5529730A (en) | 1978-08-22 | 1978-08-22 | Frequency source switching unit of digital watch |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10219578A JPS5529730A (en) | 1978-08-22 | 1978-08-22 | Frequency source switching unit of digital watch |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS5529730A true JPS5529730A (en) | 1980-03-03 |
Family
ID=14320873
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10219578A Pending JPS5529730A (en) | 1978-08-22 | 1978-08-22 | Frequency source switching unit of digital watch |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5529730A (en) |
-
1978
- 1978-08-22 JP JP10219578A patent/JPS5529730A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPS5452578A (en) | Stopwatch | |
| JPS53149076A (en) | Digital frequency detecting circuit | |
| JPS5529730A (en) | Frequency source switching unit of digital watch | |
| JPS5263764A (en) | Electronic watch with alarm | |
| JPS5362908A (en) | Bit clock reproducer | |
| JPS53116750A (en) | Portable electronic unit | |
| JPS55144586A (en) | Electronic clock having snoozing monitor function | |
| JPS5291352A (en) | 2-phase clock circuit | |
| JPS52153658A (en) | Counter circuit | |
| JPS57150221A (en) | On and off detecting circuit of switch | |
| JPS5465582A (en) | Judgement circuit of chattering time | |
| JPS5333041A (en) | Frequency step-multiplication circuit | |
| JPS5696287A (en) | Digital system battery clock | |
| JPS5567692A (en) | Counter fast feed system | |
| FR2391508A1 (en) | Time counter for electronic calculator - has logic circuit which gives control of set combination of time and number previously introduced into calculator | |
| JPS5256571A (en) | Electronic digital timepiece | |
| JPS5580089A (en) | Electronic watch with timer | |
| JPS57106951A (en) | Digital comparing circuit | |
| JPS5692493A (en) | Electronic watch | |
| JPS55134393A (en) | Indicator for electronic watch | |
| JPS5453956A (en) | Timing logic circuit | |
| JPS6447104A (en) | Protection circuit for hit of power supply for crystal oscillator | |
| JPS5423572A (en) | Electronic wristwatch with alarm | |
| JPS54115221A (en) | Digital circuit of cameras | |
| JPS52113254A (en) | Digital clock for time signal |