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
R1	2.2kΩ
R2	142kΩ (120kΩ + 22kΩ)
R3	5kΩ PRESET
C1	0.001µF (102)
IC1	NE555
IC2	7490 (SN74LS90N)
IC3	7490 (SN74LS90N)
IC4	7805 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

Digital Clock

Here as mentioned 5 IC7490s are used as counter ICs and as you can see the 5 displays are connected with seven segment displays with their respective decoder. IC4511s are used as BCD to Seven Segment decoder. All seven segment displays used are common cathode. That means all lines are grounded.

Also, the circuit shown counts only upto 8hrs. So it requires only 5 displays otherwise needs 6 displays. The circuit given is very well tested and in working condition.

The Heart of the circuit is the "Second's pulse". It was very tough to derive the 1Hz signal. After searching through the web found the idea to build the circuit using AC power lines.

In some countries the power grid operates on 60Hz i.e 60 cycles per second; and in other countries power grid operates on 50Hz.

There are some problems involved with is:

1. It is necessary that this Frequency is maintained accurately. The frequency might vary as many different electrical generators are connected with the grid and all pour power into grid.

2. Different generators must match with each other in frequency and they must also be phase locked to each other as well. Otherwise generators might overload each other.

3. Also their voltage outputs must be matched so that no generator will draw current from each others.

One can use this power line along with some CMOS ICs & can derive the 1s signal. But considering the above circumstances it requires to maintain the frequency. Which we found not so easy job.

Other than that I found a circuit which uses the Crystal circuit to get 1 second signal.

As shown the cct is built around the crystal along with 3 resistors and 2 capacitors.

Component

U1 CD4060 FREQUENCY DIVIDER

U2 CD4027 DUAL FLIP-FLOP

R1 330K Ohm Resistor

R2 3 6.8 Meg Ohm Resistor

C1 2 33pF Capacitor

Y1 32.768 KHz Crystal

DIGITAL CLOCK:

The components mainly used are:

IC7490, -- MOD-2 MOD-5 counter IC.

4511N, --- BCD to Sevensegment Decoder

HD-H103 -- SevenSegment Display

CD4060 -- Ripple Carry Binary Counter

CD4027B -- CMOS Dual J-K Master-Slave FlipFlop

BC548 -- NPN Transistor

Relay

LED :5mm RED,GREEN

Links for datasheets:

IC7490:

www.alldatasheet.com/view.jsp?Searchword=7490

IC4511N:

http://www.alldatasheet.com/datasheet-pdf/pdf/15630/PHILIPS/74HC4511N.html

HD-H103:

http://parts.digikey.com/1/parts/679648-led-7-seg-14-2mm-cc-red-rhd-hdsp-h103.html

CD4060BC:

http://www.alldatasheet.com/datasheet-pdf/pdf/26880/TI/CD4060.html

CD4027:

http://www.alldatasheet.com/datasheet-pdf/pdf/26863/TI/CD4027.html

Digital Clock

I made a Digital Clock without Micro-controller or a RTC chip (Real Time Clock) .

Digital clock now is a part of our day today life. But the it comes in different structure or format for everyone. its always seen in the right side corner of the desktop or laptop or even in our mobiles. it never stops (unless n until we do some wrong with it). So i wanted to make one for me.

But when i think of making one I was asked to make a clock only to count 8 hours.

As we are aware of the clock format as 00:00:00 i.e. it always displays Hrs:Min:Sec resptly. We learnt in the school particularly in maths to count the seconds and conversion of them to minutes or Hours.

Its very simple.... 60 seconds equal to 1 min and 60 mins equal to 1 hr. That means Hr section is derived by Min section and Min section is derived by Second section. We our observation about the clocks(digital) each Min & Second section is designed to count from 00 to 59 then resets to 00. And Hour section counts from 00 to 23(if it is 24 hr clock else counts upto 12) & resets to 00. Each cycle of count of Seconds from 00 to 59 increases 1 count in Min. Similarly each cycle of min count from 00 to 59 increases 1 count in Hour section.

Normally in Hour section when count reaches to 23 or 12 it resets to 00:00:00 i.e.oth hr. But in my project I reset the clock when it reaches to 08:00:00 that means it counts only 8 hrs.

Basic things

Always I wanted to make my own microcontroller based projects....but never got a direction.

But one day I met CRM sir who gave me the exact direction which i needed. He actually made me to make alist of the material required.

Here is the list:

To have a good set-up we need:

Soldering iron - - 25watts (Solderon company)

Soldering iron stand

Soldering iron bits or tips

Sponge -- #3 or 4

Soldering lead (called as 60-40 lead)

Cutter, Nose plier

Tester screw driver

Magnifying glass

Small knife

Other storage box

Resistor,Capacitors, Inductors

IC bases 8/14/16/20/28/40 pins as required

Wire 14 stranded,32 gauge

D connector , 9 pin connector, 2 pin connector

Relimate connector 2/3/5/20 pins

DC power supply--- variable regulated

Digital Multimeter DMM

to be continue......