I recently built a fading LED circuit according to the schematic below:
It worked fine, but then, I came across this schematic, for an LED flasher, not a fader:
My question is, what makes the difference between whether or not the LED fades, or flashes? The only thing I could figure is that the addition of the connected 7 pin would allow the capacitor to discharge to ground through it instead of going through the LED to give it the fading effect in the first circuit.
The only other main difference I see is the addition of the transistor in the first schematic, but I don’t know what difference that would make. The question is kind of pointless, but I’m hoping getting an answer will help me get some more intuition for working with the 555.
It worked fine, but then, I came across this schematic, for an LED flasher, not a fader:
My question is, what makes the difference between whether or not the LED fades, or flashes? The only thing I could figure is that the addition of the connected 7 pin would allow the capacitor to discharge to ground through it instead of going through the LED to give it the fading effect in the first circuit.
The only other main difference I see is the addition of the transistor in the first schematic, but I don’t know what difference that would make. The question is kind of pointless, but I’m hoping getting an answer will help me get some more intuition for working with the 555.