sequential timing circuit

 (1) Introduction to circuit principles through O. The OOltF coupling capacitor feeds the output of the first half of the 556 dual timer
to the input of the second half, giving a total delay equal to the sum of the individual delays. Instantly grounding pin ⑥ can start the first half of the timer. After the time interval determined by 1. 1R1C1
, the second timer starts delaying, and its value is determined by 1. 1RzG.
    (2) Component parameter selection The selection of components is shown in Figure 3-5, and there are no special requirements.
    (3) The sequential timing circuit is as shown in the figure