OH, no doubt brother. I'm going to have to back out of this discussion. I think the initial query concerned using a transistor as a switch and how the term saturation entered into the practice of transistor switches. It's been a slice but the subject has veered off to rather trivial threads of unimportant chatter. BUT as I exit I do feel compelled to defend my enormous manhood with an attempt to explain myself. So right or wrong, this will have to be my closing argument related to this particular thread. In an earlier post, I made an off the cuff remark that, had a device been a Darlington pair, then the device would contain two discreet transistor dies and be wired accordingly to satisfy the definition of a Darlington pair. I will still support that statement citing the description that I will assume is contained in the original patent application. What I believe has happened is that a cascaded pair of transistors has merely become common place to be referred to as a Darlington pair, rather they are two separate pieces or etched into a single chip of silicon, for ease of understanding. It is the same situation that leads people to refer to any brand name locking pliers as ViseGrips. Most often an adjustable wrench is called a Cresent wrench. Technically incorrect but generally accepted by the majority. Trivial matters but it appears that upholding one's social credit may become a must do in the changing landscape of everyday life. Looking forward to more chats. M