If you have a better two-word term to give to a beginner I am happy to hear it. The phrase transistor "turns on" is quite standard in beginner teaching of transistor theory and although being incomplete in describing all forms of transistor biasing it is very beginner accessible, in the like of; "switch turns on" and "relay turns on".
Hello Mr RB,
thank you for your reply. May I ask you:
1.) Is there any necessity to use a „two-word“ term to roughly describe what a transistor is doing?
What happens after the transistor is „on“? I think, one should spend some more words to answer the original question.
Let me try it with one simple sentence:
A fixed dc voltage between collector and emitter allows a current to flow between these two nodes that can be controlled by another voltage between base and emitter, which may vary around a bias voltage of approx. (0.6-0.7) volts.
2.) Let me give another example related to BJT operation:
Based on the simple relation Ic=B*Ib (or ic=h21*ib) many people and even textbooks clearly state: The BJT is a current-controlled device.
However, knowing the physical background it is obvious that such a description is false.
Is there any good reason not to confront the beginner with the truth?
Is it really more complicated to explain the working principle of this voltage-controlled device? I don’t think so because it works for the FET.
3.) Summary: I think, simplification is good and necessary - it is even unavoidable – however, down to a certain degree only. I am afraid, if we to much simplify the physics of the electronic world the beginner does not feel the necessity – and is not motivated enough – to look „behind the curtain“. Why not leave him alone for a while with a lot of open questions?
According to my experience in educating engineers it is very important for beginners and students to know about their „gaps“. This is the first and most important step to fill the gap – in a second step - with knowledge.