555 power-on delay output low level circuit

(1) Introduction to circuit principle The circuit is shown in Figure 3-2. When
  the circuit is connected to the power supply, because the capacitor Cl has no time to charge, the ② and
  @ pins of the 555 are at low level, and the ③ pin outputs a power meter. As the capacitor Cl
  charges , the potential of pins ② and ⑥ of 555 begins to rise. When the potential of pin ② rises to
  V(z, the circuit flips, and the output terminal U{) changes from high level to
  low level and remains there. Go down. Delay time tw -1. iRc. This kind of
  circuit is mostly used to control the partial circuit of the whole machine circuit to
  disconnect the power supply and stop working after a certain period of time after starting the machine.
    (2) Component parameter selection The selection of components
  is shown in Figure 3-2 , and there are no special requirements.
    (3) The 555 power-on delay output high-level circuit is shown in Figure 3-2. shown