Experiment No.6, 7, 8 and Transistor. (part1)

1, What is a transistor?
Remember the basic p-n junction we learn from normal rectifying diode? This concept is used again in a revolutionary electronic device called Transistor, the base of TODAYS compact, advance electronic devices which aren't meant to be without the transistor. Now, the transistor uses the p-n basis in a more advance way: instead of just p-n, its either p-n-p or n-p-n, which they called the bipolar semi-conductive junction. 

We can start by consider a transistor is like 2 diode back to back. The goal is to use a small amount of amperage, to active a sleeping high amperage just for the sake of turning thing ON and OFF things... / the language of our digital world that has never changed.

Best explaining about the transistor is to go and actually do:
Experiment no.6: 
  First thing we were told: that there is a base, a collector and an emitter.
In NPN, small current flows from Base to Emitter ( as p to n), which turns on the connection between Collector and Emitter, which allows a bigger current to mount from collector to emitter.
In PNP, small current flows from Emitter to base ( as p to n) which allows an amplified current from Collector to Base ( p to n). 

So when having a transistor in your hand, it is important to know the layouts if you have no clue what type of transistor it is, by using a multimeter set to diode test mode, and check n label each 2 terminals. Put them together as a form of 2 diodes back to back you will be able to figure out where is where or NPN or PNP type. 

While doing this, if there are 2 forward diode you have spotted, then the one with a slightly higher Voltage drop is from the emitter whether it is anode or cathode. Why? Because higher voltage drop means harder to push through, as the current through this spot is slightly restricted than the amplified current through from the collector. Plus, remember this is a semiconductor and a amperage amplifier, so its obvious that when small current trigger the big current, you would expect the collector- base junction or collector- emitter junction to act pretty much like a conductor wouldn't you?


So with that being said, this is what we would expected: