North Park Secondary School
Computer Engineering 11 (ICE 3M0)
Digital Lab 17
R-S Flip Flop
To investigate the difference output states of an R-S flip flop circuit.
|One SK-50 breadboarding socket
||One 7400 TTL integrated circuit(NAND)
||Two 470 OHM resistors
||One 9V Battery
- Assemble the circuit on the breadboard.
- Observe LED1 and LED2 for steps 3 to 9. Be sure to record your observations after each step.
- Connect inputs A to high and B to low.
- Leave input A to high and change B to high.
- Connect inputs A to low and B to high.
- Connect inputs A to high and leave B to high.
- Connect inputs A and B to low.
- Change inputs A and B from low to high at the same time.
- Repeat (#8) several times.
- What is the relationship of a Q and Q in procedures (3) and (5)?
- What does the bar over the Q mean?
- Explain how the outputs Q and Q inverted are obtained from the inputs R and S in procedure 3.
- Explain why outputs Q and Q inverted do not change from procedure 3 to 4.
- Repeat questions 3 and 4 for procedures 5 and 6.
- Explain the outputs Q and Q inverted in procedure 7.
- Explain the inconsistent results in procedure 8.
- Why is this circuit called a flip flop?
Summarize in table form the operation of an R-S flip flop
Page Lasted Updated 10:21 AM 10/14/2003