ROBOT.LK

Hello Friends,
This is a simple trick about simple logic circuit designing.I think,This is important for O/L IT and A/L Physics.
I use my poor English.Sorry for it.Never misunderstand.

I explain it using some examples.

Example 1:
Create a simple logic circuit for detect prime numbers from 0 to 7.

1.simple it,write a truth table...

convert 0 - 7 to binary.
0=000
1=001
2=010
3=011
..
..
7=111

2.write output as "1" for prime numbers only.

Table- 3.This is the point...
Get lines which output is "1" and write expression like following.

At input number is 2(=010) output is "1". Now write expression like this. If input is "0",get as "Bar". In this line,A and C are "0",therefore,we get A bar and B bar.
?

ok..this is another line.
Get line which input is 5.
A=1 ... therefore, write expression A.Not A bar.
B=0 ... therefore,write B bar.
C=1 ... Write C
At finally,Expression should be, ok...End of trick.if you have a question,ask...

this is all expression corresponding to each line. 4.Now,input this all expression to OR gate.Get output(Q)... 5.Create circuit.
According above output expression we want,
A bar,B bar,C bar.therefore,We want to use NOT gate.
For get input for last OR gate,want to use three input AND gate.
Last we want a 4 input OR gate.

This is the circuit...

Example 2:
This is a question given G.C.E(A/L )-2004 Question number:-5.(iii)

Create a circuit for emergency lamp for automatically on at night power cutting.This light has a switch for light up the lamp at anytime.
Use following input.
A=1 : switch on
A=0 : switch off
B=1 : at night
B=0 : at day
C=1 : while power cutting
C=0 : while power ok

use output,
X=1 : emergency lamp on
X=0 : emergency lamp off

OK...Now answer....

1.write a truth table.
2.Get lines which output is "1" and write expression.(red on above table.)

line 3 :
A=0
B=1
C=0
Therefore,Expression should be, line 5 :
A=1
B=0
C=0
Therefore,Expression should be, line 6 :
A=1
B=0
C=a
Therefore,Expression should be, line 7 :
A=1
B=1
C=0
Therefore,Expression should be, line 8 :
A=1
B=1
C=1
Therefore,Expression should be,
3.Write Output expression using OR operation. 4.Create circuit...
According to above output expression,
We want,
NOT Gate - 2 (for B bar and C bar,No A bar in expression)
3 input AND Gate - 5
5 input OR Gate - 1
OK
I think this may be useful to you.
If you have any problem,ask.
Sorry for my poor English again.

Nice!

2012 question too was intererting. I done it first of all.

[ Post made via Mobile Device ]

Did not answer Electronic question?I think It's the easiest question than others.

Nandika wrote:
Did not answer Electronic question?I think It's the easiest question than others.

The Electronic one was on gates. And Electricle one was on resistance. Normally I don't like number calculations because I do mistakes. So I did electronic (on gates) one.


[ Post made via Mobile Device ]

I simplified your both of circuits using Boolean Logics. This is out of A/L physics, but used in Maths (probability).

01.
02.

Nice....
I haven't more knowledge about this boolian equation.
Actually ,I wished someone post about simplified circuit.

Please,If you can post this simplification step by step.
Thanks.

oh! I've done two mistakes in my last reply. The correct ones are below.
[ Post made via Mobile Device ]

Excellent work Rksk....

But,I have a problem in (02). Where is + A.B.(C bar + C) in 3^rd line of simplification?

Explain some about red sentence ..

thank you...

Nandika wrote: Where is + A.B.(C bar + C) in 3^rd line of simplification?

A.B bar.(C bar + C) + A.B.(C bar + C) = A.B bar + A.B = A.(B bar + B) = A

Nandika wrote: Explain some about red sentence ..

Let's think X = Abar.B.Cbar + A
if A = 0; X = 1.B.Cbar + 0 = B.Cbar
if A = 1; X = 0.B.Cbar + 1 = B.Cbar + 1

now let's think Y = B.Cbar + A
if A = 0; Y = B.Cbar
if A = 1; Y = B.Cbar + 1

Both give same answer.

I got it,Rksk thanx

As this,According to Complementary law....
Am I correct...Please tell?