Experiment 14 - Signal Delay with 555

For many applications it is necessary to delay signals. Just think of applications in automation and control systems. Such a signal delay circuit can be set up with two monoflops.

Consider the circuit shown. You recognize surely two monoflops. The OUT output of the first monoflop is connected through the capacitor C4 with the TRIGGER input of the second monoflop.

Circuit diagram signal delay with two NE555.

If you press the pushbutton switch S1, LED1 and LED2 displays the result of the first monoflop. LED3 and LED4 repeat the behaviour with a delay of 5 seconds.

During the switching time of the first monoflop, the OUT output of the IC1 is HIGH. When it falls after 5 sec. to LOW, this is the signal for the second monoflop.

Circuit signal delay with two NE555. (Enlarge)

But now to astable multivibrators...