I've seen a boost converter circuit on YouTube, and the guy uses a second coil, wound on top of the first coil, and in the same direction, it is connected to the base of a BJT. The BJT acts as a switch for the boost converter. Now how does the second coil turn the BJT on and off?
From what I've read(and watched on yt) so far, the inductor acts as an open INITIALLY and then becomes a short at 5tau, but does the current only keep flowing from that point on? If so, how can the bjt turn off(and on again) after it is turned on?
Link to the video.