How does a transistor amplify current or voltage?

[Ratchit]

Brownout,

Ie is a controlling variable, not a controlled one. Ie controls Ic, not the other way round. In transistors, all signals are important. To ignore any signal, as in ignoring Ie, is a brain dead argument.

I said before, I am not ignoring or disregarding Ie. But if Vbe controls Ic, it also controls Ie, because Ie and Ic and proportional to each other.

I didn't threaten to report you. You're only answer to the monumental amount of information that has been presented here is to just write the same flawed verse over and over and over. That's just spamming.

One could say you are repetitive too.

What we know goes on. We've given you the causal view. You've given us nothing.

What you think it is, anyway. I gave you my explanation, even if you reject it.

Until you do, you don't know enough to discuss it intelligently.

That is your conclusion.

Ratch

 

[BrownOut]

But if Vbe controls Ic, it also controls Ie, because Ie and Ic and proportional to each other.

Proportional because Ie controls Ic.

One could say you are repetitive too.

Those who support CC have put in the effort to get it right. We've given you complete analysis, including terminal equations, junction currents and charge analysis, and recicprocity, amongst many other analysis and physical explanations. You have nothing but rote recitation of the same discredited verse.

What you think it is, anyway. I gave you my explanation, even if you reject it.

What I've proven. You’ve given no explanation. You’ve not treated causality that you harp on and on about.

That is your conclusion.

It's self evident.

 

[Sceadwian]

Brownout I love how you state things like 'it's self evident' when this is the 182nd post on the subject and there's still no consensus, it is obviously NOT self evident.

 

[BrownOut]

Actually, there is consensus. At least five experienced, knowledgable people support the CC model. I don't care what anyone thinks is the answer. But we have smart, experienced people here, and I'm signing on with them

 

[Mikebits]

Actually, there is consensus. At least five experienced, knowledgable people support the CC model. I don't care what anyone thinks is the answer. But we have smart, experienced people here, and I'm signing on with them

The US Navy seems to agree with you as well. **broken link removed**

 

[Sceadwian]

This is like the blind leading the blind this thread.

The mathematical model that works well and is known best does not describe the atomic interactions directly, regardless of how well it works in practice. The Navy is teaching weapons to push buttons and run warships not allow a greater understanding of the fundamental nature of reality to filter into it's ranks.

I tried to argue back a ways that in zero time an instantaneous moment, current can't flow, there can only be an electric field which is the proof that it's the electric field, the voltage between two points that actually controls the semi conductors state. Problem is, I don't understand the math or quantum theory well enough to actually quote equations which would act as a proof.
Another problem though. No other user here can either, just quoting what we've heard or been taught verbatim, or throwing up a few 'known realities' from this or that scientific giant means nothing.

Nothing useful is occurring here aside from a few users arguing, quoting whatever fits their viewpoint with absolutely no regard for learning or understanding. It's like watching monkeys throw poop, and I feel tainted by it for adding comments even to the point I have.

I can be sure of one and only one thing, and that is that tot one single posted 'fact' in this thread means jack squat to the reality that is occurring which runs the devices that are at the point of contention. It'll keep going on without us understanding it, and we'll never quiet manage it.

 

[Mikebits]

If you had taken Calculus then you would know that zero time does not exist and your point is invalid.

 

[Claude Abraham]

This is like the blind leading the blind this thread.

The mathematical model that works well and is known best does not describe the atomic interactions directly, regardless of how well it works in practice. The Navy is teaching weapons to push buttons and run warships not allow a greater understanding of the fundamental nature of reality to filter into it's ranks.

I tried to argue back a ways that in zero time an instantaneous moment, current can't flow, there can only be an electric field which is the proof that it's the electric field, the voltage between two points that actually controls the semi conductors state. Problem is, I don't understand the math or quantum theory well enough to actually quote equations which would act as a proof.
Another problem though. No other user here can either, just quoting what we've heard or been taught verbatim, or throwing up a few 'known realities' from this or that scientific giant means nothing.

Nothing useful is occurring here aside from a few users arguing, quoting whatever fits their viewpoint with absolutely no regard for learning or understanding. It's like watching monkeys throw poop, and I feel tainted by it for adding comments even to the point I have.

I can be sure of one and only one thing, and that is that tot one single posted 'fact' in this thread means jack squat to the reality that is occurring which runs the devices that are at the point of contention. It'll keep going on without us understanding it, and we'll never quiet manage it.

I don't think so. "Blind leading the blind?" Semiconductors, especially at the quantum level, are indeed difficult to understand, but the behavior is consistent & predictable. We have what appears to be universal concensus that the bjt is CC externally. But one member claims, as well as you, that internally Vbe is the ultimate control variable. First of all, the argument is a bit far fetched right on its face. Ib/Vbe/Ie are all both external & internal values. Current is continuous. Electrons injected into the emitter transit through said emitter, & so on. Vbe is also external as well, but when charges transit into the terminals, voltages appear internally. So how can anyone say "CC externally, but VC internally"?

As far as the state of the bjt goes, freezing time does not zero out the currents. If charge is q, then dq/dt = i = current. The current, by definition, is the time derivative of the charge. If we look at an instant in time, do we only see charges, not currents? The instantaneous rate of change is the current. What an argument! If we freeze time, the charges are still, meaning no current, but the voltage remains due to charge separation. Thus voltage is still present but current vanishes!

But don't forget, that voltage is defined in terms of transport, or motion. The voltage between 2 points a & b, is by definition, the energy per unit charge expended transporting said charge from a to b. Hence, if we freeze time, & disallow mention of the past & future, then voltage has no meaning either. At an instant frozen in time, all charges are in fixed locations. To say that a voltage still exists is acknowledging time & motion. Between 2 plates of a charged up cap, there is an E field. In frozen time, what does this mean? It means that a small charge, too small to influence the E field magnitude, would accelerate towards 1 of the plates. Thus voltage has no meaning & is undefined for frozen time frames.

Every time, the critics present an argument as to why Vbe should be treated as the control variable, it does not withstand scrutiny. So another argument gets presented. It was originally offered, that Ie/Ib are consequential, w/ Vbe being the cause. But anyone w/ a scope & current & voltage probes can easily demonstrate that Vbe lags behing Ib/Ie in time. Also, it takes energy to establish and/or change an E field value. Energy over time is power, which is the product of I & V. Conservation of energy demands that Ib/Vbe/Ie must be all non-zero in order to change a bjt state.

So, another straw is being grasped at. In frozen time, the charges are all still. Meaning, Ib/Ie ceases to exist, but Vbe still exists due to charge separation. Another problem is that Ic vanishes as well. You claim that Vbe must be what is controlling Ic, because Ib/Ie cannot exist in a frozen time reference frame. But the quantity being controlled, Ic, vanishes as well. Wow! Frozen time! So by freezing time, moving objects become still. So what happens to the energy & momentum, which by law, must be conserved. They exist in fluid time, but at every solitary instant they disappear???!!!

This time freeze argument is the best ever. This thread is comedic entertainment. Every time the critics put forth an argument, which is quickly refuted, they spin another tale, more fantastic & un-credible than the last. This frozen time frame argument will be very hard to top.

But don't underestimate the critics. They can spin a tale like no one else can. I have to give them credit regarding that.

 

[BrownOut]

But don't underestimate the critics. They can spin a tale like no one else can. I have to give them credit regarding that.

How 'bout I beat them to it: If time runs backwards, then E leads I! There you have it!

 

[MrAl]

Hi again,


This probably wont help, but...
To get charge to flow, you have to have an electric field, but to get an electric field, you had to have assembled some charges, but to assemble some charges you have to have had an electric field, but to...

It was a dark and stormy night. The Captain said, "John, tell us a story", so John began..."It was a dark and stormy night, the Captain said, 'John, tell us a story', so John began...It was a dark and stormy night, the Captain said 'John, tell us a story', so John began...It was a...

 

[Claude Abraham]

Hi again,


This probably wont help, but...
To get charge to flow, you have to have an electric field, but to get an electric field, you had to have assembled some charges, but to assemble some charges you have to have had an electric field, but to...

It was a dark and stormy night. The Captain said, "John, tell us a story", so John began..."It was a dark and stormy night, the Captain said, 'John, tell us a story', so John began...It was a dark and stormy night, the Captain said 'John, tell us a story', so John began...It was a...

Very valid point. Whenever someone starts invoking "causality", this comes to mind. Some have argued that charge motion is due to E fields. But E fields ae created by separating charges, requiring work, & the transport of said charges constitutes current. So a current, & work is needed to separate charges to get an E field. Then other charges are acted upon by said E field, which gives up a portion of its energy, requiring a current, or more charges to replenish the energy.

It truly is a vicious circle indeed. Anybody here at this forum over the last 7 yrs. or so knows me for my "chicken/egg" viewpoint of charge/E field/current/voltage/power/energy" pecking order. Anyone who thinks they can state which causes which is deluded. What we perceive as "cause" is a transfer of energy and/or momentum. The "cause" is the delivery of energy, the "effect" is the receiving of energy.

Everything goes along smoothly until someone starts acting up with their causality obsession. Every attempt to describe bjt behavior has been exhausted, & 62 yrs. after the bjt patent was filed, every bjt producer describes them as CC. The critics say it is only a superficial model - external. They then present "internal" data to oppose the CC view. But when I & others refute them w/ physics, they tell me I'm going to deep into QM/particle physics. So my physics viewpoint is too superficial & too deep at the same time.

Thanks for your comments Mr. Al, & just 1 more thought. You earlier mentioned "charge control", QC, as the best model. I agree that at the mIcro level, QC offers info regarding time delays & switching speed that CC does not offer. For a FET, the QC model is used for speed as well, since the VC model does not address that issue. Also, current & voltage are both ratios of more basic quantities, charge, energy, & time. Charge is the most fundamental quantity.

But as an EE, some apps do not push the speed limits of the bjt or FET device, so QC analysis is not needed. CC for a bjt & VC for a FET give answers that are pretty darn good. I'm sure you'd agree. Thanks.

 

[MrAl]

Hello Claude,


Thanks for making that more clear. It appears that our viewpoint depends not only on charge and field, but where we enter the observation in space time. It's like in order to know how the transistor conducts we have to trace its action back to the big bang. Only then it seems we would know what came first. We might then be able to follow the evolution of the universe right up to the moment when the collector emitter starts to conduct current. We might then be able to claim, "See, X came before Y right after the big bang". Wouldnt it be something if both X and Y were created at the very same instant.

 

[Ratchit]

Brownout,

Proportional because Ie controls Ic.

Proportional because Ie is mostly Ic.

Those who support CC have put in the effort to get it right. We've given you complete analysis, including terminal equations, junction currents and charge analysis, and recicprocity, amongst many other analysis and physical explanations. You have nothing but rote recitation of the same discredited verse.

Yes, you have completely explained why, functionally speaking, a BJT is a CC device.

What I've proven. You’ve given no explanation. You’ve not treated causality that you harp on and on about.

Yes, I have explained it. Remember the helmsman and rudder analogy?

It's self evident.

Not to a lot of people it is not.

Actually, there is consensus. At least five experienced, knowledgable people support the CC model. I don't care what anyone thinks is the answer. But we have smart, experienced people here, and I'm signing on with them

A consensus does not constitute proof. There was a consensus at one time that every planetary body revolved around the Earth. There are also smart, experience people who don't think the same you do either.

Ratch

 

[Ratchit]

Mikebits,

The US Navy seems to agree with you as well. Transistor Amplifiers

You should choose a different reference, because in the same paragraph they also say:

A vacuum-tube amplifier is also a current-control device. The grid bias controls the plate current.

They go on further to say:

The whole secret to understanding amplifiers is to remember that fact. Current control is the name of the game.

Which is not quite true. You can amplify voltage with a current amplifier and amplify current with a voltage amplifier. In that respect they are symetrical. Often both happens at the same time.

I know there is a lot of good information in those manuals, but like Wiki, it is not always correct.

Ratch

 

[Ratchit]

Claude,

But one member claims, as well as you, that internally Vbe is the ultimate control variable. First of all, the argument is a bit far fetched right on its face. Ib/Vbe/Ie are all both external & internal values. Current is continuous. Electrons injected into the emitter transit through said emitter, & so on. Vbe is also external as well, but when charges transit into the terminals, voltages appear internally. So how can anyone say "CC externally, but VC internally"?

The charges that are injected into the emitter are controled by Vbe, which lowers the emitter base barrier voltage caused by the uncovered charges. Vbe is the last control element of Ic/Ib/Ie. I have not said external or internal except to refer to functional and causal. I don't see how thinking about a transistor this way is far fetched.

As far as the state of the bjt goes, freezing time does not zero out the currents. If charge is q, then dq/dt = i = current. The current, by definition, is the time derivative of the charge. If we look at an instant in time, do we only see charges, not currents? The instantaneous rate of change is the current. What an argument! If we freeze time, the charges are still, meaning no current, but the voltage remains due to charge separation. Thus voltage is still present but current vanishes!

But don't forget, that voltage is defined in terms of transport, or motion. The voltage between 2 points a & b, is by definition, the energy per unit charge expended transporting said charge from a to b. Hence, if we freeze time, & disallow mention of the past & future, then voltage has no meaning either. At an instant frozen in time, all charges are in fixed locations. To say that a voltage still exists is acknowledging time & motion. Between 2 plates of a charged up cap, there is an E field. In frozen time, what does this mean? It means that a small charge, too small to influence the E field magnitude, would accelerate towards 1 of the plates. Thus voltage has no meaning & is undefined for frozen time frames.

I hope you are not making that argument for me. I never said that causal control depends on time.

Every time, the critics present an argument as to why Vbe should be treated as the control variable, it does not withstand scrutiny. So another argument gets presented. It was originally offered, that Ie/Ib are consequential, w/ Vbe being the cause. But anyone w/ a scope & current & voltage probes can easily demonstrate that Vbe lags behing Ib/Ie in time. Also, it takes energy to establish and/or change an E field value. Energy over time is power, which is the product of I & V. Conservation of energy demands that Ib/Vbe/Ie must be all non-zero in order to change a bjt state.

Of course Ib and Ic are consequential to Vbe. That is what casual means, doesn't it? Who cares if the electric field propagating at the speed of light cause charges to flow at the speed of cold molasses? Who cares if the response of I & E are picoseconds apart? Of course energy has to be transferred for Vbe to sustain itself. That does not define causality. The bottom line is that both Ib and Ic are tied together by the equations referenced in Sedra and Smith. Ib does not change Ic without Vbe changing with it.

So, another straw is being grasped at. In frozen time, the charges are all still. Meaning, Ib/Ie ceases to exist, but Vbe still exists due to charge separation. Another problem is that Ic vanishes as well. You claim that Vbe must be what is controlling Ic, because Ib/Ie cannot exist in a frozen time reference frame. But the quantity being controlled, Ic, vanishes as well. Wow! Frozen time! So by freezing time, moving objects become still. So what happens to the energy & momentum, which by law, must be conserved. They exist in fluid time, but at every solitary instant they disappear???!!!

Most of the argument in the above paragraph does not apply to me. "Frozen time" does not have to be used to explain causality.

This time freeze argument is the best ever. This thread is comedic entertainment. Every time the critics put forth an argument, which is quickly refuted, they spin another tale, more fantastic & un-credible than the last. This frozen time frame argument will be very hard to top.

I have been consistent is my arguments.

But don't underestimate the critics. They can spin a tale like no one else can. I have to give them credit regarding that.

Some do and some don't. Gray and Searles seem to think that Vbe is a valid concept.

Ratch

 

[Ratchit]

MrAl,

To get charge to flow, you have to have an electric field, but to get an electric field, you had to have assembled some charges, but to assemble some charges you have to have had an electric field, but to...

I hope what you are saying is just a point for clarification, and not a reason for saying that causality cannot be determined. Yes, charge flow requires a voltage, and energy is exchanged and transferred when current exists. Voltage can be generated by the separation of charges like the Wimshurt machine does, or by magnetic means the way a dam generator works. That is not important.

What we are talking about is not about the cause and effect of current and voltage in a conductor. We are talking about what is the most basic control element in a BJT. I maintain that it is Vbe because both Ic,Ie,and Ib are intimately tied to it. It does not matter whether Vbe or Ib happen before or after eventwise, or whether the source supplying Vbe has to be able to supply the energy. It does not matter what occurs in Quantumland. The causality is what is really controlling the BJT, and that is Vbe. I will reiterate again that controlling Ib is the functional control of the transtor, and should always be used for design and calculation. But "under the hood" it is really Vbe that is calling the shots.

I illustrated my point earlier with a helmsman and rudder. The helmsman has functional control of the boat, but it is really the rudder that causes the boat to turn. That is what I mean by causality.

Ratch

 

[BrownOut]

Proportional because Ie is mostly Ic.

Proportional because Ie controlls Ic. It doesn't work the other way round

Yes, you have completely explained why, functionally speaking, a BJT is a CC device.

Also why a BJT is a CC device at the junction level. There's actually more to explain, but as you're not getting it, I won't waste any more of my time.

Yes, I have explained it. Remember the helmsman and rudder analogy?

Which has nothing to do with BJT operation. You've utterly failed to explain aything about BJT's.

A consensus does not constitute proof. There was a consensus at one time that every planetary body revolved around the Earth. There are also smart, experience people who don't think the same you do either.

I never claimed that it did. But the proof is in the details we've posted.

 

[Claude Abraham]

MrAl,



I hope what you are saying is just a point for clarification, and not a reason for saying that causality cannot be determined. Yes, charge flow requires a voltage, and energy is exchanged and transferred when current exists. Voltage can be generated by the separation of charges like the Wimshurt machine does, or by magnetic means the way a dam generator works. That is not important.

What we are talking about is not about the cause and effect of current and voltage in a conductor. We are talking about what is the most basic control element in a BJT. I maintain that it is Vbe because both Ic,Ie,and Ib are intimately tied to it. It does not matter whether Vbe or Ib happen before or after eventwise, or whether the source supplying Vbe has to be able to supply the energy. It does not matter what occurs in Quantumland. The causality is what is really controlling the BJT, and that is Vbe. I will reiterate again that controlling Ib is the functional control of the transtor, and should always be used for design and calculation. But "under the hood" it is really Vbe that is calling the shots.

I illustrated my point earlier with a helmsman and rudder. The helmsman has functional control of the boat, but it is really the rudder that causes the boat to turn. That is what I mean by causality.

Ratch

But how does Vbe relate to being "the rudder". Vbe exists because p-n jcns are not ideal. An ideal revtifying jcn would be open in reverse, short in forward direction. If a semiconductor w/ zero bandgap energy existed, charges entering the emitter would transit through the base onward to the collector. The no. of e- collected is controlled by the no. of e- emitted. After Ib/Ie are changed by Sue, Ic increases as a result, but a little later, Vbe increases. But Vbe increasing is not the control mechanisn. In order to supply more electrons for the emitter to emit, work must be done. When Sue cranks it up, it is the increased current/voltage from the mic resposible for Ie/Ib increasing. As a consequence, Vbe increases after the fact, but Ic has already begun to increase w/o Vbe increasing yet.

The intermediate variable at the jcn is Ie. Although Ib & Vbe change as well, only Ie contributes to Ic. Ib & Vbe are necessary because perfect semiconductors cannot be produced. The Ie is not controlled by the Vbe. The eqns you keep referencing are functional relations, not causal.

Start w/ the n-p-n as a pair of back to back diodes. The upper diode is the b-c jcn, described by Shockley's diode eqn
Ic = Ics*exp((Vbc/Vt)-1). Since Vbc is negative, a very small Ic exists, leakage of the reverse biased p-n b-c jcn.

The lower p-n jcn, b-e is forward biased. So we have
Ie = Ies*exp(Vbe/Vt)-1), a large current since Vbe is positive.

If the base region was very wide, say 1.0 mm, the above relations are what we get. Ie = Ib, a large value, w/ Ic being a small leakage.

But if the base region is made ultra thin, say 1.0 um, we find that Ic measures almost as large as Ie, w/ Ib being quite small, Ib = Ie-Ic. Instead of 2 mere series diodes, we have transistor action. The b-c jcn is reverse biased, but Ic is almost Ie. The Shockley eqn needs another term. The additional current is Ic = alpha*Ie. So we get

Ic = alpha*Ies*exp((Vbe/Vt)-1) + Ics*exp((Vbc/Vt)-1).

But sonce the 2nd term is much smaller than the 1st, we round off & use Ic = alpha*Ies*exp((Vbe/Vt)-1). Also, alpha is very near to unity, so some texts omit alpha, w/ the resulting eror being 1 to 2%.

The Vbe eqn, which I've called eqn 2), is derived from Shockley's diode eqn, plus the eqn 3), the transistor action eqn. Ie & Vbe do have a functional relationship per eqn 2). But Vbe is directly related to Ib & Ie, but indirectly related to Ic. Ie has a direct relation w/ Ic per eqn 3).

In order for Ic to change, all that is needed is a change in Ie. In the process, Ib & Vbe change as well, but that is not what changes Ic. Ic starts increasing prior to Vbe increasing, & Vbe continues to increase after Ic has settled.

No brainer at all. Transistor action is Ic = alpha*Ie. Any test w/ instruments will affirm. A good software simulator might show this, but the models have to be really accurate. Low end packages won't work.

 

[Ratchit]

Brownout,

Proportional because Ie controlls Ic. It doesn't work the other way round

Vbe controls Ic and thereby Ie as stated in Sedra and Smith.

Also why a BJT is a CC device at the junction level. There's actually more to explain, but as you're not getting it, I won't waste any more of my time.

It is not, the Vbe at the junction controls Ic as stated in Sedra and Smith.

Which has nothing to do with BJT operation. You've utterly failed to explain aything about BJT's.

Sedra and Smith have done so.

I never claimed that it did. But the proof is in the details we've posted.

Then why did you name five people what agree with you? Actually it is a lot more. Your explanations do not encompass the equations given in Sedra and Smith.

Ratch

 

[MrAl]

MrAl,



I hope what you are saying is just a point for clarification, and not a reason for saying that causality cannot be determined. Yes, charge flow requires a voltage, and energy is exchanged and transferred when current exists. Voltage can be generated by the separation of charges like the Wimshurt machine does, or by magnetic means the way a dam generator works. That is not important.

What we are talking about is not about the cause and effect of current and voltage in a conductor. We are talking about what is the most basic control element in a BJT. I maintain that it is Vbe because both Ic,Ie,and Ib are intimately tied to it. It does not matter whether Vbe or Ib happen before or after eventwise, or whether the source supplying Vbe has to be able to supply the energy. It does not matter what occurs in Quantumland. The causality is what is really controlling the BJT, and that is Vbe. I will reiterate again that controlling Ib is the functional control of the transtor, and should always be used for design and calculation. But "under the hood" it is really Vbe that is calling the shots.

I illustrated my point earlier with a helmsman and rudder. The helmsman has functional control of the boat, but it is really the rudder that causes the boat to turn. That is what I mean by causality.

Ratch

Hello again,


I was not saying that causality is impossible, i was saying that to prove it we would have to go back to the big bang to do it.
On the other hand, if you draw some limits to where you say we come in at point (t,x,y,z) then we could probably claim either form of control based on what t, x, y, and z we chose.
The thing is, when we apply a base voltage nothing happens at first because the base charge has not been changed yet. Once it starts to change then it requires a steady flow of base charge to keep things going. The voltage allows the flow of charge, but the charge must flow. Ideally with no band gap the voltage could be zero but the flow of charge would still have to keep going or transistor action would cease. The voltage in that case doesnt have to be there, but then again that's in a transistor i dont think has been invented yet so some might want to discard that altogether. In that case i still dont see how we can claim any kind of control is more innate to the transistor. We usually view charge as the control i think because there is always some base capacitance and little inductance. That capacitance has to be charged up for transistor action to occur. Also, it's a pretty well known phrase that in order to turn a bipolar transistor off we have to "sweep the charge out of the base region", which means we have to draw that charge out of the transistor that caused it to stay turned on. In that case we might apply a negative voltage to the base to get faster turn off times, but still it's the movement of the charge that allows us to remove it the first place in order to turn the transistor off. There's also a known quality of the transistor called "storage time". What exactly is being stored if it is not charge? We often shunt the base to ground to turn the transistor off, but there is a big delay while the charge carriers leave the base region. I've never heard anyone say, "We have to short out the base to turn the transistor off", except for beginners in circuit analysis, because shorting the voltage to zero does not turn the transistor off, it's the exiting of the charge carriers that actually make the transistor turn off and this is very evident due to the fact that the transistor still does not turn off even with base shorted to emitter, until after sufficient charge carriers have had time to leave. If we say the voltage really did turn it off, then i guess we can say that anything in the past was the cause and that wouldnt make as much sense as looking at the charge instead.
In fact, if we want to get down to tooth and nails we can say that no initial change in voltage produces a change in collector current, even a small one nor even a large one, because the charge carriers have to have time to start moving. It's very hard to say the thing is voltage controlled then when it doesnt respond well and yet it responds instantly to a change in current.
Also, i think if we MODULATE the base with a certain frequency F and well chosen voltage and current waveshape (and levels) we could cause an inversion of action. The voltage goes up but the current goes down!

This brings us to another interesting story with a similar theme. A friend of mine always asks me why we can not measure the voltage of an NiMH battery in order to determine if it is fully charged or half charged or whatever the state of charge is. He exclaims, "I can measure the voltage with my meter". I always have to remind him that the charge can be one half of the total capacity of the cell in both of two different cells, while one cell measures 1.4v and the other measures 1.5v. It's not about voltage because there are various ways the voltage can change and not affect the charge stored, it's all about the charge. Of course we could study that one or two cells and plot their performance to some possibly high degree of accuracy, which may lead us to a relationship between the voltage and other variables and the state of charge, but that is very hard to do and so we usually talk only about the charge and the time, when we want to know the state of charge. Wouldnt it be a little silly to say, "My cell now has 1.6v stored on it", especially when that could change and the actual charge didnt. Notice we even had to resort to using the word "on" instead of "in". We store books 'on' a shelf, but we store charge 'in' a battery.

The base emitter voltage of one transistor can be 0.6v and the other transistor 0.65v but if the current gains are the same 10ma will produce the same collector current in both transistors. Of course you can also say that two other transistors have both the same base voltage but different collector currents if the gain is different.
The horse draws the carriage the carriage doesnt draw the horse, we assume that, but the carriage does pull back on the horse as much as the horse pulls on it.

Lastly, a low leakage transistor that has been turned on and then had the base disconnected would turn off after a delay because of it's internal resistance discharging the base region. Can we say that there is some internal voltage that is responsible for the turn off and not the current leaving the base? Maybe we can, but it doesnt happen until the carriers leave. Interesting though, there does have to be a difference in potential for anything to start moving, and if we view that potential as external (ie we entered the picture at some late (t,x,y,z)) we might claim voltage control.