Many engineers have now don't know how to use the triode tube, the once as the most core components, circuit design as an electronic engineer is the most basic knowledge are not most of the engineers, can say is the tragedy of the whole industry, cause for many reasons, of course, I hope everyone here can speak freely!
I simply drew a basic circuit model, and we're going to assume that this triode's Vbe = 0.7 v, Hfe = 10, Icm = 100mA.
Let's talk about what is called saturated triode, what exactly is saturated pressure drop, BE is partial, BC is the partial saturation, or when the transistor is in a state of saturation, the base current control of the transistor will not work?
1: when we adjust the adjustable resistance, R1, R1 = 4.3 K, we can calculate from ohm's law,
Ib = (50.7) / 4.3 K = 1mA,
So we can compute IC equals Hfe * Ib = 10mA,
And if I were to adjust R3 at this time, and make R3 equal to 500 ohms, by computing we could get Vc is equal to 5 minus 10mA times 0.5 K, which is equal to 0V,
This is when we look at the triode triode voltage, Vb = 0.7, Vc = 0, Ve = 0,
2: when we adjust the adjustable resistance, R1, R1 = 4.3 K, we can calculate from ohm's law,
Ib = (50.7) / 4.3 K = 1mA,
So we can compute IC equals Hfe * Ib = 10mA,
If this time I adjust R3, make R3 = 1 k ohm, through calculation we can get a Vc = 510 ma * 1 (k) = 5 v, appear back to 5 v? Of course not, because there is no negative pressure,
So the voltage of the Vc is going to stay at 0V, so let's take a look at what the Ic is
Through ohm's law we can figure out
Ic = (5  Vc) / 1K = (50) / 1 = 5mA, not 10mA, which is why,
This is the time when we look at the triode triode voltage, Vb = 0.7, Vc = 0V, Ve = 0V,
3: when we adjust the adjustable resistance, R1, R1 = 2.15 K, we can calculate by ohm's law,
Ib = (50.7) / 2.15 K = 2mA,
Then we can calculate the IC = Hfe * Ib = 20 ma, if this time I adjust the R3, make R3 = 1 k ohm, through calculation we can get a Vc = 5  (20 ma * 1 k) = 15 v, back to appear to 15 v, also won't, of course, also because there is no negative pressure,
So the voltage of the Vc is going to stay at 0V, so let's take a look at what the Ic is
Through ohm's law we can figure out
Ic = (5  Vc) / 1K = (50) / 1 = 5mA, which is also 5mA, not 20mA, which is why,
This is the time when we look at the triode triode voltage, Vb = 0.7, Vc = 0V, Ve = 0V,
If the saturated state of the triode is as fragrant tea, as defined by the snow, on the three states should be saturated, but the actual transistor saturation yet, I can certainly assure you that all have no, why, because more cases of Ic 10 ma, ma, ma 5 is far from the biggest current collector Icm = 100 ma,
What the hell is wrong, there is a book tells us that this is the BE is partial, BC the partial saturation conclusion is wrong, this is an irresponsible conclusion, teachers and textbooks are not able to accurately tell us what is the triode,
How the base is controlling the collector.
In fact, I think a comparison is better, and the process of control is like we're using our hands to push a gate, the flow of water through the gate,
The magnitude of our strength is the base current Ib,
The opening size of the gate is Ib * Hfe,
The current flowing through the gate is the Ic,
So if the collector to a large reservoir, we push, the collector gate open gate, the greater the flow will be more, we don't have to push the collector smaller gate gate open, water will become smaller, the water will be affected by the size of the gate size control.
So if the collector connected to a water pipe, we push again, collector gate the gate open with a thermal power station chimney is useless, because the water was only so big, again big channel also no use.
So what is our base current control, is the current collector capacity, rather than a collector how many current control, only when the collector has enough ability to us to control the gate can achieve the goal of controlling the flow,
So in the true sense of saturated should is greater than our biggest gate can flow through the water, is the truth, is the gate is the biggest, again big also curb your water.
That is the biggest water gate through the Ic is restricted by the opening size of the gate is the Ib * Hfe, but is unable to control the actual flows through the water, to see whether the water supply of the equipment. But the maximum will not exceed the limit of the gate.
