As shown in the calendar clock circuit for the digital display. It also shows month, day, hour, minute, second, and week, month, day, week, automatic conversion can be trouble 2 times a day, a sleep timer function within 59min. The calendar clock is keeping accurate, easy to adjust, when to see clearly at night, making easy.
How it works:
The heart of the circuit IC1 is a PMOS LSI LM8364. 4 feet for the 12/24 hour clock choice side, a 24-hour high. Should be suspended 6 feet 7 feet from the base when the input signal is 60Hz, then 7 feet high when the input from the 50Hz time base signal. 5,8,9,10,11,12,14,16,18 feet high were connected, they can achieve their respective functions. When the alarm or sleep timing signal arrives, 17 feet, 42 feet or 15 feet out of the high level of sustainable 59min signals, control VT4, and then control the buzzer by the VT4. Of course VT4 can also control other circuits (such as relays, radio). 2,3,20 to 41 feet can be made directly drive LED digital display. In addition to these pins output "hours" signal, but also output "May Day" and "second" signal, these pins are common. To 5 feet and 10 feet high at the same time then, in the "hours" output circuit "May Day"; to 10 feet to 5 feet high then low in the "sub" output "seconds ", the figure of IC2 is a COMS decimal counter / divider integrated circuit CD4017, is to IC1 to 5 feet, 10 feet high to provide timely, so that output of IC1 on the fast day over and over again, after midnight, second signal. IC2 also controls VTl ~ VT3, so that the contents of a digital display other content is not displayed. Since the human eye of vision phenomenon, the flashing LED is not observed, see also the month, day, hour display. IC2 also play a role in tuning options. Press AN1, the display will be locked (random), the display is the current content can be adjusted. Repeatedly pressing the AN1, need to adjust the contents of the option. IC3 is a bit binary serial counts were CMOS14 and oscillation frequency integrated circuits CD4060, using it as core components of the signal time-base circuit, IC1 and IC2, respectively, to provide 60Hz and 240Hz in the time base signal. The decision of the circuit when the clock go accuracy, and can fine-tune the C2, so that within days the error in the 0.3s. To further improve the accuracy of travel time, operating voltage should be stable IC3; or use other 50Hz or 60Hz signal time-base circuit, the use of higher resonant frequency crystal.
To the CD4017 IC4 constitute the core of weeks show circuit. IC4 time base signal (day) from IC1 pin 42 (alarm 2) provides that the reduction side (15 side) then the output of the first 7 (6 feet), so that when the output of IC1 goes high, 42 feet, IC4 the output of the 3,2,4,7,10,1,5 pin goes high in turn, direct-drive LED displays week. In this circuit, Sunday's show did not use 3 feet high, but by the power supply through resistor R3 to provide current limiting after, so that the LED has been lit on Sunday, providing references, make the night a week to see more convenient and accurate. Because time is often 2 IC1's downtown is not set at zero, so the conversion may be delayed a week a few hours, but no major impact on the use. If you need to be downtown two times a day, shall set the alarm an alarm before 2; if only given a daily alarm 1, alarm 2, then just set the zero point, disconnect the R10, with the trouble to root for the exact 2 Display week with the time base signal, only to realize a set alarm alarm function.
When the AC power supply is disconnected from the battery to continue to IC1, IC3, IC4 power, timing, timing to keep, but IC2 stop working, VT1, VT2, VT3 end, LED display part is not lit, so you can extend the battery time . In the AC power supply, charge the battery by R1.
Select components: integrated circuits IC1 choose LM8364, IC2 select CD4017B, IC3 select CD4060B, IC4 select CD4017B. NPN-type transistor to be used, bigger is better magnification. 10 LED display with digital control and 9 should be used in bright light emitting diodes, or ultra-high brightness type, use common cathode LED type. Color and size can be selected according to their own preferences. For example: Display Date 0.8 inch green LED display of time with 0.8 inch red LED display seconds the red LED with 0.56 inches, center of a selection of red light-emitting diode, use the green ring 6, the two use the yellow diodes. Battery can be used 3.6V60mAh of nickel-cadmium batteries. 7.5V or 9V buzzer should be selected small. 8 buttons can be directly used television to radio stations using the 8 self-locking switch (spring to be removed, so that loss of self-lock function). Should use the power transformer secondary AC voltage is 9V 3W's.