Thursday 16 February 2012

Digital clock using LM8560...


After making clock using IC7490 and CD4060,Cd4027......I turned to make the Digital clock using the LM8560.


The LM8560 is alarm equipped digital clock IC. It is capable of directly driving LED display equipment with the Bilt-in driver. Also we can run it with12V DC.


Datasheet for LM8560 can be found here.
http://www.paulanders.com/G5-LED/ver1/datablad.pdf




Main problem I faced to get 50hz. Some circuit which I studied was getting the 50hz/60hz using the mains transformer. With which I felt that it wouldn't be that much accurate to get the desired frequency. Because some places do have the fluctuations with mains power. 


Then I found some circuits are using the CD4541 and a crystal to get the exact 50HZ. Also, I found a circuit to 50Hz using Ic7490 and a simple 555 timer Ic.


Here,the circuit is built using CD4541....The programmable timer with 16-bit binary counter in-build. And a crystal of 3.2768MHz.


Once the circuit is ready one should not face big problems in it. 


It has total six switches out of which 2 switches are used for the mode selection.
Also, as the LM8560 has the display driver in-build we can directly connect the multiplexed 4-digit display to it. 
I have checked whether we can run the single seven segment display with it or not...but its not possible.


The circuit shown for 50hz:





PARTS LIST
R12.2kΩ
R2142kΩ (120kΩ + 22kΩ)
R35kΩ PRESET
C10.001µF (102)
IC1NE555
IC27490 (SN74LS90N)
IC37490 (SN74LS90N)
IC47805 Regulator







some references:


http://www.electronicecircuits.com/electronic-circuits/accurate-50hz-oscillator-circuit-using-555-and-7490



http://www.eleccircuit.com/lm8560-digital-clock-24-hr-with-alarm/




http://kitsnspares.com/admin/pdffiles/Remote%20controlled%20Real%20Time%20Clock.pdf





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