- #1
gsingh2011
- 115
- 1
I have a kit for designing circuits and this was one of the projects in the book:
That was the best scan I could make... On the right side, right next to the NPN transistor there is an LED and to the right of that there is a 6V power source, positive side is up, negative is down. If there's anything else unclear about the picture, ask me.
So the circuit does exactly what the book says it would: the light turns on for a few seconds and then turns off. But looking at the connections made, the current has a direct path through the LED without even going through the transistors, so it seems like it should stay on at all times. I think the basic idea of the rest of it is that when the capacitor is charged it provides the base current necessary to allow the collector-emitter current to flow. Whether it flows or doesn't flow, I still see one direct path for the current to take through the LED. Why does it still turn off after a few seconds?
That was the best scan I could make... On the right side, right next to the NPN transistor there is an LED and to the right of that there is a 6V power source, positive side is up, negative is down. If there's anything else unclear about the picture, ask me.
So the circuit does exactly what the book says it would: the light turns on for a few seconds and then turns off. But looking at the connections made, the current has a direct path through the LED without even going through the transistors, so it seems like it should stay on at all times. I think the basic idea of the rest of it is that when the capacitor is charged it provides the base current necessary to allow the collector-emitter current to flow. Whether it flows or doesn't flow, I still see one direct path for the current to take through the LED. Why does it still turn off after a few seconds?