1) Connect battery to supply 5V to the circuit.

2) Press Switch 1 for input R (Reset) and Switch 2 for input S (Set).

The switch in ON state is and the switch in OFF state is

3) Different combination of LEDs lit up for different combination of inputs.

i)When the S and R inputs are both low,feedback maintains the Q and Q' outputs in a constant state, with Q' the complement of Q.

ii)If S is pulsed high while R is held low, then the Q output is forced high, and stays high when S returns to low.

iii)If R is pulsed high while S is held low, then the Q output is forced low, and stays low when R returns to low.

iv)The R = S = 1 combination is called a restricted combination because, as both NOR gates output 0s, it breaks the logical equation Q = not Q.

The LED in OFF state is and the LED in ON state is .

4) Click on "Add" Button to simultaneously add data to the Truth Table and generate the Timing Diagram.

5) Repeat Steps 2 to 4 for another set of data.

6) Click "Print" to get the print out of the Truth Table.

Construction of NOR Gate Latch and verification of its operation

Battery

IC 7402

Switch 1 (R)

Switch 2 (S)

Q

Q
+
-












      TRUTH TABLE            

Serial No. R S Qn-1 Qn-1 Qn Qn Remarks

              TIMING DIAGRAM

    
    Q=1

    Q=0

    Q=1

    Q=0

    S=1

    S=0

    R=1

    R=0