From the internal circuit diagram of the NE555 you can see that the TRIGGER input Pin 2 (TRIG) is connected to a comparator. The second input of the comparator is connected to the voltage divider, at which the voltage V = 1/3 Vcc = 3 V applies. The output of the comparator is connected to the SET input of the RS latch.
![]() Internal circuit diagram TRIGGER input NE555. |
Now consider the circuit shown...
![]() Circuit TRIGGER input NE555. (Enlarge) |
![]() Circuit diagram TRIGGER input NE555. |
As soon as you push the pushbutton switch S1...
But how can you switch the NE555 back again?