How an lcd clock & led clock works
1.Introduction
Electronic clock, also known as digital alarm clock (digital display clock), is a digital circuit technology to achieve hours, minutes, seconds of the device, compared with the mechanical clock, intuitive as its main notable feature, and because of non-mechanical drive, has a longer service life, compared with the quartz clock movement drive, more accurate.Electronic clock has become an indispensable necessity in People's Daily life. It is widely used in personal family and public places such as station, wharf, theater, office, etc. It brings great convenience to people's life, study, work and entertainment.
Compared with other types of clocks, its characteristics can be summed up as "two strong and one weak ": better than the mechanical clock in viewing time is significant, better than the quartz clock in walking time is accurate, but its weakness is more monotonous in display time.Electronic clock is more convenient and practical.
2. Function description
The clock function of electronic clock: with optional 24h(hour) or 12h(hour) timing mode, display hours, minutes, seconds; With the function of rapid calibration in hours, minutes and seconds; Can set the alarm time, alarm time for 1min(minutes), more than 1min(minutes) automatic stop; With artificial stop function, stop no longer operation again, will no longer occur; It has the function of telling time on the hour. With the progress and development of science and technology, some electronic clocks also have the function of projection, which is derived as the auxiliary function of many other products.
Its timing period is 24 hours, display full scale for 23 hours 59 minutes 59 seconds, with the function of calibration and time function.Therefore, a basic digital clock circuit mainly consists of decoding display, "hour", "minute", "second" counter, calibration circuit, time circuit and oscillator.The main circuit system is composed of second signal generator, "hour, minute, second" counter, decoder and display, calibration circuit, hour telling circuit.The second signal generator is the time base signal of the whole system, which directly determines the accuracy of the timing system. It is generally realized by the quartz crystal oscillator plus frequency device.The standard second signal is fed into the "second counter". The "second counter" uses a base 60 counter and sends out a "minute pulse" signal every 60 seconds. The signal will be the clock pulse of the "minute counter".The sub-counter also uses a base 60 counter. Every 60 minutes, it sends out a "time pulse" signal, which is sent to the "time counter".Time counter "using 24 base timer, can realize the 24 hours of a day cumulative.Decoding display circuit "hour", "minute", "second" counter output state with a seven-segment display decoder decoding, through the seven-segment display.The hourly timing circuit generates a pulse signal according to the output state of the timing system, and then triggers an audio generator to tell the time.Calibration circuit is used for "hour", "minute", "second" display numbers to calibrate and adjust.
