Electronic Dice using 4026ic, 555 timer ic and logic gates..

  I HAVE MADE DIGITAL ELECTRONIC DICE USING LOGIC GATES AND BOOLEAN ALGEBRA IN VARIOUS COMBINATION TO DEVELOP LOGIC IN PURELY ANALOG CIRCUIT. WE HAVE USED DIFFERENT LOGIC GATES AND THEIR COMBINATIONS TO OBTAIN THE DESIRED RESULT FOR OUR PURPOSE.

WE HAVE MADE AN ELECTRONIC DICE USING A 7-SEGMENT DISPLAY,4026 DECODER IC,555 TIMER,PULSE GENERATION IC AND SOME LOGIC GATES SUCH AS AND GATE AND NOT GATE

      THE 4026 DECODER IC IS USED TO DISPLAY THE NUMBERS ON 7-SEGMENT DISPLAY FROM 0-9 ONE BY ONE. WHEN THE PULSE GENERATOR IC (555 TIMER IC) GIVES PULSES TO 4026. FIRST OF ALL SOME LOGIC IS TO BE DEVELOPED SO THAT THE DECODER IC RESETS AFTER THE NUMBER 6 BECAUSE A DICE CONTAIN NUMBER UPTO 6. WHEN THE LOGIC IS DEVELOPED WE WILL BE SUCCESSFULL IN MAKING THE 7-SEGMENT COUNT FROM 0-6 ONLY.

      AFTER THAT IF WE HAVE TO STOP THE DISPLAY AT A PARTICULAR NUMBER SO THAT THE PLAYER GETS A NUMBER TO PLAY.

       WORKING OF A SIMPLE 7-SEGMENT DISPLAY

                            4026 IC IS USED TO DISPLAY THE NUMBERS ON 7-SEGMENT DISPLAY. THE NUMBER ON 7- SEGMENT CHANGES AT EVERY PULSE GENERATED FROM THE PULSE GENERATOR. WE HAVE USED 555 TIMER IC AS PULSE GENERATOR.

·                  DEVELOPMENT OF LOGIC FOR DISPLAYING NUMBERS UPTO 6:-

 TRUTH TABLE FOR THE 7-SEGMENT DISPLAY

	a	b	c	d	e	f	g
0	1	1	1	1	1	1	*
1	*	1	1	*	*	*	*
2	1	1	*	1	1	*	1
3	1	1	1	1	*	*	1
4	*	1	1	*	*	1	1
5	1	*	1	1	*	1	1
6	1	*	1	1	1	1	1
7	1	1	1	*	*	*	*
8	1	1	1	1	1	1	1
9	1	1	1	1	*	1	1

1.   THIS IS THE TRUTH TABLE FOR THE DECODED DISPLAYS ON A 7-SEGMENT.

2.   OUR MAIN PURPOSE IS TO CREATE A LOGIC SUCH THAT AFTER THE NUMBER 6 IS DISPLAYED ,THE 4026 IC RESETS AND THE DISPLAY IS RETURNED TO  0,INTSEAD OF 7.

3.    LOOK AT THE LOGIC TRUTH TABLE CAREFULLY. NOTICE THE COMBINATIONS FOR NUMBER 7 OF a LED AND d LED i.e a=1 AND d=0 (CIRCLED IN TABLE).NO OTHER NUMBER HAS THE SAME COMBINATION AS THAT a=1 ; d=0.

4.    THIS IS OUR OBSERVATION NOW AS WE CAN SEE THAT FOR THOSE 2 WIRES TO 7-SEGMENT DISPLAY HAS 4 POSSIBLITIES. THEY ARE:-

a	d
0	0
0	1
1	0
1	1

 WE WANT A TRUTH TABLE SUCH THAT THE O/P IS HIGH AND THE OUTPUT IS ONLY WHEN THE I/P IS :=

a	d
1	0

      

BECAUSE WE WANT TO RESET THE CIRCUIT WHEN THE NUMBER IS CHANGING FROM 6 TO 7 THROUGH THIS COMBINATION.

·     DESIRED TRUTH TABLE :-

a	d	Y
0	0	0
0	1	0
1	0	1
1	1	0

The logic circuit comes out to be :-

   

THE TRUTH TABLE OF THIS LOGIC IS SAME AS THAT OF THE DESIRED.

SO,NOW WE HAVE DEVELOPED A LOGIC THAT WILL MAKE THE COUNTER COUNT TILL 6

FIG:- REPRESENTATION OF HOW TO CONNECT IN CKT:-

NOW ,SO AS TO STOP THE DISPLAY AT A PARTICULAR NUMBER WE SHOULD HAVE A OUTPUT FROM THE PULSE DECODER OF TYPE.

FIRST OF ALL WE MADE A CIRCUIT FROM 555IC WITH THE SWITCH AT THE O/P OF 555,BUT THE RESULT WERE NOT SATISFACTORY ACCORDINGLY. LATER WE CAME TO LEARN THAT THE END O/P WAS NEITHER PERFECTLY HIGH NOR PERFECTLY LOW. SO WE SHIFTED THE SWITCH FROM THE O/P END TO THE VCC  OF 555IC. SO THE FINAL CIRCUIT IS SHOWN BELOW.