etymology of word "transistor"

[PG1995]

Hi

I'm trying to understand the etymology of word "transistor". Please help me.

Merriam Webster states: transfer + resistor; from its transferring an electrical signal across a resistor.

Would you please tell me how does a transistor 'transfer resistance'? Thanks for your help.

Regards
PG

 

[carbonzit]

Hi

I'm trying to understand the etymology of word "transistor". Please help me.

Merriam Webster states: transfer + resistor; from its transferring an electrical signal across a resistor.

Would you please tell me how does a transistor 'transfer resistance'? Thanks for your help.

The usage seems to be widespread; the ARRL Handbook describes it thus:

The word "transistor" was chosen to describe the function of a three-terminal PN junction device that is able to amplify signal energy (current). The inherent characteristic is one of "transferring current across a resistor".

Seems to make sense, as transistors are, after all, semiconductors, which have some inherent resistance. But I'd be curious to know more about the exact etymology.

 

[Brevor]

When I was in school the instructor told us the word transistor was derived from the words
"transfer resistor", because in an amplifier circuit it transfers the output voltage between itself and the load resistor.

 

[carbonzit]

But that in no way distinguishes it from any other amplifying device (vacuum tube, magnetic amplifier, carbon amplifier, etc.). I think the "resistor" is inherently part of the transistor.

 

[The Electrician]

It has to do with a property of two terminal "black boxes" described in terms of Z parameters. The Z21 parameter is "transresistance", analogous to the "transconductance" of a vacuum tube (or nowadays, a FET).

See:
https://www.pbs.org/transistor/album1/pierce/index.html

https://www.pbs.org/transistor/album1/pierce/naming.html

 

[MrAl]

Hello,

To me it always meant simply a device that changes resistance on demand. "Trans" and "Resistor" when put together seem to suggest like trans-gender that the second part of the word had changed, and with trans-gender the gender changes, and the way a resistor changes is in value, so with transistor the resistance either goes up or down and that's what the external effects suggest.

 

[k7elp60]

The way I look at it is....as the base/emitter junction resistance changes the collector/emitter resistance also changes. If the base current increases, the collector current increases.

 

[ericgibbs]

Post #5 is the is the definition I was taught in the 60's, Z parameter analysis.

 

[PG1995]

Hello,

To me it always meant simply a device that changes resistance on demand. "Trans" and "Resistor" when put together seem to suggest like trans-gender that the second part of the word had changed, and with trans-gender the gender changes, and the way a resistor changes is in value, so with transistor the resistance either goes up or down and that's what the external effects suggest.

Thanks a lot, everyone. Despite all the replies, unfortunately, I'm still unable to understand the meaning of word "transistor". Obviously, it is because of my limited knowledge.

@MrAl: What you say also applies to a variable resistor. As varsistor and transistor are two different things, so in my humble opinion they should have different reasons for their descriptive names. Please correct me. Thanks.

I see some people says transistor is made up from two terms "transconductance" and "varistor" which is non-ohmic variable resistor. "transconductance" is rate of change of current per volt, deltaI/deltaV.

Please help me. Thanks

 

[The Electrician]

Did you look at the links I gave you in post #5? John Pierce coined the word, and he explained his thinking:

They'd built the device, but they didn't have a name. (Point-contact solid state amplifier isn't exactly catchy.) Walter Brattain wanted something that could capture the feel of the amplifier in a single word. He asked around in the lab but no one had come up with anything. One day in May as he was walking down the hall thinking about the problem, he bumped into his friend, John Pierce.

Now, Pierce had a way with words -- he would go on to become an accomplished science fiction writer -- so Brattain asked him if he had any thoughts. Thinking out loud, Pierce pointed out that just as the vacuum tube had transconductance, the new amplifier had the electrical property of transresistance. He also knew that a number of electronic devices had come out recently with names, such as varistor and thermistor.

How about 'transistor.' he suggested? And Brattain responded: "Pierce, that's it!"

Also:

"The way I provided the name, was to think of what the device did. And at that time, it was supposed to be the dual of the vacuum tube. The vacuum tube had transconductance, so the transistor would have 'transresistance.' And the name should fit in with the names of other devices, such as varistor and thermistor. And. . . I suggested the name 'transistor.'"

Regardless of what people might think the word means, the true etymology of the word is known to us from the explanation given by John Pierce, the man who coined the word.

 

[PG1995]

Did you look at the links I gave you in post #5? John Pierce coined the word, and he explained his thinking:

They'd built the device, but they didn't have a name. (Point-contact solid state amplifier isn't exactly catchy.) Walter Brattain wanted something that could capture the feel of the amplifier in a single word. He asked around in the lab but no one had come up with anything. One day in May as he was walking down the hall thinking about the problem, he bumped into his friend, John Pierce.

Now, Pierce had a way with words -- he would go on to become an accomplished science fiction writer -- so Brattain asked him if he had any thoughts. Thinking out loud, Pierce pointed out that just as the vacuum tube had transconductance, the new amplifier had the electrical property of transresistance. He also knew that a number of electronic devices had come out recently with names, such as varistor and thermistor.

Thank you very much, Electrician.

I think the phrase in bold is hampering my understanding. "dual" is supposed to double of something with same characteristics. I understand what "transconductance" is but don't know what that "transresistance" is. Would you pleae help me with it? Thanks.

 

[MrAl]

Thanks a lot, everyone. Despite all the replies, unfortunately, I'm still unable to understand the meaning of word "transistor". Obviously, it is because of my limited knowledge.

@MrAl: What you say also applies to a variable resistor. As varsistor and transistor are two different things, so in my humble opinion they should have different reasons for their descriptive names. Please correct me. Thanks.

I see some people says transistor is made up from two terms "transconductance" and "varistor" which is non-ohmic variable resistor. "transconductance" is rate of change of current per volt, deltaI/deltaV.

Please help me. Thanks

Hi,

Yes but a variable resistor already had a name: potentiometer

"Transresistance" could be taken to mean simply "A change in resistance" as i tried to explain in my previous post. That's what i believe the originator of the name meant to imply. Names for things dont have to be exclusive either.

 

[The Electrician]

Thank you very much, Electrician.

I think the phrase in bold is hampering my understanding. "dual" is supposed to double of something with same characteristics. I understand what "transconductance" is but don't know what that "transresistance" is. Would you pleae help me with it? Thanks.

Have a look at this article: https://en.wikipedia.org/wiki/Two-port_network

Under the heading "Admittance parameters" you will see a 2x2 matrix with elements y11, y12, y21, y22. The elements on the main diagonal (y11 and y22) are the "driving point admittances" (conductances) at the input and output of the two-port. They allow you to calculate the ratio of current to voltage (that ratio is an admittance or a conductance) at a point in a circuit when you apply a signal to that point.

The off-diagonal elements (y12 and y21 in the case of a two-port; a more complicated circuit could have a larger admittance matrix with more than 4 elements) are the "transfer admittances". They allow you to calculate the current in a part of the circuit which is different from the part where you apply the signal (voltage). The word "transfer" is used because those elements of the matrix relate the voltage in one part of the circuit to the current in another part of the circuit.

When analyzing vacuum tube circuits, the tube can be treated as a two-port, and the admittance parameters are appropriate to use because the input impedance of a vacuum tube is extremely high at low frequencies. The y21 parameter is the important parameter that relates the current in the plate circuit to the voltage applied to the grid. It's full name is "forward transfer admittance" (or "forward transfer conductance" at low frequencies). The name is commonly abbreviated to "transconductance".

When John Pierce coined the name "transistor", the transistors available at the time were mostly point contact transistors. Their input impedance was much lower than that of a vacuum tube, and it was more appropriate to use impedance parameters rather than admittance parameters to analyze transistor circuits.

Look under the heading "Impedance parameters" in: https://en.wikipedia.org/wiki/Two-port_network.

The parameters z11 and z22 are the "driving point impedances". Just as in the admittance parameter description of a two-port, the z12 and z21 parameters are transfer parameters, and they describe the relation between a current in one part of a network and the voltage in another part, hence the word "transfer". The important parameter in this case is z21, which accounts for the property of providing gain. The full name of this parameter is "forward transfer impedance" (or "forward transfer resistance" at low frequencies). It is usually abbreviated "transresistance". That's what Pierce was thinking of when he coined the word "transistor".

 

[The Electrician]

"Transresistance" could be taken to mean simply "A change in resistance" as i tried to explain in my previous post. That's what i believe the originator of the name meant to imply.

"Transresistance" could be taken to mean simply "A change in resistance", but why do that when it already has a specific meaning which has been in use since about 1930 in connection with network analysis?

It means the ratio between the voltage that appears at one part of a circuit and a current applied to another part of the network, the voltage being the result of the applied current. For example, with a two-port device such as a transistor, the transresistance is the ratio of a signal voltage at the output to a signal current applied to the input.

This is precisely what John Pierce meant when he referred to "transresistance".

 

[PG1995]

Have a look at this article: https://en.wikipedia.org/wiki/Two-port_network

Under the heading "Admittance parameters" you will see a 2x2 matrix with elements y11, y12, y21, y22. The elements on the main diagonal (y11 and y22) are the "driving point admittances" (conductances) at the input and output of the two-port. They allow you to calculate the ratio of current to voltage (that ratio is an admittance or a conductance) at a point in a circuit when you apply a signal to that point.

The off-diagonal elements (y12 and y21 in the case of a two-port; a more complicated circuit could have a larger admittance matrix with more than 4 elements) are the "transfer admittances". They allow you to calculate the current in a part of the circuit which is different from the part where you apply the signal (voltage). The word "transfer" is used because those elements of the matrix relate the voltage in one part of the circuit to the current in another part of the circuit.

When analyzing vacuum tube circuits, the tube can be treated as a two-port, and the admittance parameters are appropriate to use because the input impedance of a vacuum tube is extremely high at low frequencies. The y21 parameter is the important parameter that relates the current in the plate circuit to the voltage applied to the grid. It's full name is "forward transfer admittance" (or "forward transfer conductance" at low frequencies). The name is commonly abbreviated to "transconductance".

When John Pierce coined the name "transistor", the transistors available at the time were mostly point contact transistors. Their input impedance was much lower than that of a vacuum tube, and it was more appropriate to use impedance parameters rather than admittance parameters to analyze transistor circuits.

Look under the heading "Impedance parameters" in: https://en.wikipedia.org/wiki/Two-port_network.

The parameters z11 and z22 are the "driving point impedances". Just as in the admittance parameter description of a two-port, the z12 and z21 parameters are transfer parameters, and they describe the relation between a current in one part of a network and the voltage in another part, hence the word "transfer". The important parameter in this case is z21, which accounts for the property of providing gain. The full name of this parameter is "forward transfer impedance" (or "forward transfer resistance" at low frequencies). It is usually abbreviated "transresistance". That's what Pierce was thinking of when he coined the word "transistor".

Thanks a lot, MrAl, Electrian.

@Electrician: I genuinely appreciate your effort to help me. Thank you for that. But the problem here on the forums is that members are very nice and helpful but sometimes they forget that what kind of audience they are addressing. People like you who have knowledge of this technical stuff should try to make the stuff accessible to persons like me who are amateurs and not brilliant as you are. Unfortunately, because of my limited knowledge I wasn't able to understand much of what you said above but I still regard your attempt at helping me.

Best wishes
PG

 

[The Electrician]

You said "I understand what "transconductance" is but don't know what that "transresistance" is."

If you will explain what your understanding of transconductance is, perhaps I can show you how to extend that understanding to "transresistance".

 

[Sceadwian]

PG1955, what are you not understanding? A device based primarily on transconductance is a device that's control terminal allows the amount of electricity being conductive by the device to be changed. Transresistance is the same thing, only the controlling terminal effects the practical resistance of the device, current follows suit with the change in resistance but the fundamental effect is an electrically controlled one way variable resistor.