Lesson 11 Flip-Flop、Counter、Timer

Experiment 1 Flip-Flop

Flip-Flop is a kind of memory component. Press switch 1 then loosen, the LED will keep on shining until press switch 2.

S means Set, R means Reset.

One 4043 IC include 4 RS-Flip-Flops.

Experiment 2 Counter

Press switch again and again, these 4 LEDs will shine alternately. The counter can count from 1 to 10. So we connect pin 10 to pin 15 in order to let the counter count to 4, then begin with 1 again.

If we input high level voltage to pin 13, the counter will stop. So we connect pin 13 to the ground.

Experiment 3 Timer 4098

One 4098 include 2 timers. We use the upper timer in 4098 now. Press switch then loosen, the LED keep on shining for 2 seconds. The time is decided by R and C.

If R take 30KΩ, C take 100μF Then time=0.7*30K*100*10(-6)=2.1seconds。

(1) Press switch then LED on for a while

(2) Press switch then LED on for a while

(3) Press switch then LED1 on , LED2 off

(4) Press switch1 Then LED on, Press switch2 then LED off

(5) 2 Timers in one 4098 IC