Hi,
Just wanted to let you know there's a spare "(" or a missing ")" in the transistors chapter
http://www.allaboutcircuits.com/vol_3/chpt_4/2.html

here:

If the switch is closed as in (Figure above (b), however, electrons will be able to flow from the emitter through to the base of the transistor, through the switch and up to the left side of the lamp, back to the positive side of the battery.

great job with the site, anyway

 

http://www.allaboutcircuits.com/vol_3/chpt_4/2.html#03078.png

Transistor: (a) cutoff, lamp off; (b) saturated, lamp on.

If the switch is open as in (Figure above (a), the base wire of the transistor will be left “floating” (not connected to anything) and there will be no current through it. In this state, the transistor is said to be cutoff. If the switch is closed as in (Figure above (b), however, electrons will be able to flow from the emitter through to the base of the transistor, through the switch and up to the left side of the lamp, back to the positive side of the battery. This base current will enable a much larger flow of electrons from the emitter through to the collector, thus lighting up the lamp. In this state of maximum circuit current, the transistor is said to be saturated.

Verified .