Now we are get somewhere. If you truly understand the definition of AC I continually quote, you will realize that Alternating Current is not "the value of current alternating". Alternating Current is the alternating current direction (polarity). The fact is the change in voltage is directly related to the constant change in current direction (polarity). As I stated earlier, The change in voltage in a AC current is by-product of alternating electron flow.
I actually I didn't say that either. I stated that current flow in one direction is DC. My point is that a voltage is not necessarily constant just just because current is flowing in one direction. As my example showed.
AC is a current changing both magnitude and polarity:
Alternating current - Wikipedia, the free encyclopedia
Which one?
Previous!
Or in American terms previous mean any one that were posted before?
In Russian terms Предыдущий means The One that Was Right Before.
That means, this one:
My advice is to form an International Consilium, and evaluate definitions.
Why? Because American definitions are good for business. For example, American Degrees were invented by Fahrenheit who designed commercial product for temperature measurement. European degrees were invented by Celsius who did physical experiments. Later, Kelvin made another scale, still using Celsius Degrees, and again, with physical properties in mind.
Let's start with Russian definitions. They are more scientific, so Russian engineers are better in scientific approach, while American engineers are better in commercial approach. That's why I dream of a team, where I design, and American engineers develop production. Want to join?
So, Russian term of what Americans call Direct Current, is Constant Current, or Stable Current. (Постоянный Ток).
Russian term of what Americans call Alternating Current, is Variable Current, or better Ever-Changing Current. (Переменный Ток)
What about other languages?
My advice is to form an International Consilium, and evaluate definitions.
Why? Because American definitions are good for business. For example, American Degrees were invented by Fahrenheit who designed commercial product for temperature measurement. European degrees were invented by Celsius who did physical experiments. Later, Kelvin made another scale, still using Celsius Degrees, and again, with physical properties in mind.
Let's start with Russian definitions. They are more scientific, so Russian engineers are better in scientific approach, while American engineers are better in commercial approach. That's why I dream of a team, where I design, and American engineers develop production. Want to join?
So, Russian term of what Americans call Direct Current, is Constant Current, or Stable Current. (Постоянный Ток).
Russian term of what Americans call Alternating Current, is Variable Current, or better Ever-Changing Current. (Переменный Ток)
What about other languages?
You are absolutely right about different degrees of accuracy of different definitions, in different languages.
Electricity and electronics terms in Hebrew were initially borrowed mostly from German, later on the English terms dominated.
Anyhow, the terms DC and AC became part of the English language, so it will be almost impossible for any English speaking person to replace Direct Current with Constant Current and Alternating Current with Ever-changing Current.
Actual I near said that Direct Current is "Constant Current" In fact i said the exact opposite. DC is the flow of current (electrons) in one direction, I also stated that current flowing in one direction does not constitute a constant voltage/current.
In reading the second line it was your definition of AC the matches the Russian term you posted.
[/QUOTE]
AC is Alternating Current. Period. That means, the Value of the Current is Alternating. Contrary to Constant. Constant is not Alternating. It is always the same, by definition. If it changes, it is not Constant anymore.
[/QUOTE]
Semantics...it's all an argument of word choice. Vacuum tubes don't care what we humans call it. The original poster's question revolved around the workings of a triode. If the cathode is at ground potential, the plate is above ground, and the grid is negative, less current will flow than if the grid is more positive. If the grid voltage is fluctuating, the plate current will fluctuate. Besides terminology, where is the confusion coming from?
If the grid is driven positive with respect to the cathode (but at a lower potential than the plate), will electrons be accelerated towards the plate, and thus allow more current to flow than if the grid were at 0V w.r.t. the cathode? Or will electrons flow through the grid? Or a combination of both?
Kyle
If the grid is driven positive with respect to the cathode (but at a lower potential than the plate), will electrons be accelerated towards the plate, and thus allow more current to flow than if the grid were at 0V w.r.t. the cathode? Or will electrons flow through the grid? Or a combination of both?
Kyle
Let's see...
Cold->Hot
High->Low
Direct->...
Alternating->...?
American Definitions from Wikipedia are good for selling electricity to consumers, to distinguish one Product from another, but American language does not have terms usable for electronics, so commercial terms were borrowed. Engineers see well the difference (as Michael Koster said, they need 3 month to comprehend this difference), while novices are confused.
To honour Fourier we ought to ask what the French call AC and DC. Then maybe Fourier would tell us that the 0Hz component is DC and everything else is AC. Fourier also tells us that almost all signals* can be covered by Fourier, so that means that almost all signals consist of AC plus DC. Those signals with no 0Hz are pure AC. Those with only 0Hz are pure DC. Everything else is a combination of the two. Don't ask "is this AC or DC?"; instead ask "how much AC and how much DC in this signal?"
* "Almost all signals" means continuous, or no more than a finite number of finite discontinuities - this covers all signals in electronics. We will gloss over the distinction between periodic and non-periodic signals, as this is supposed to be about the basics.
If you want to argue about AC and DC you must understand Fourier. This is why I said that textbooks start with simple half-truths.
* "Almost all signals" means continuous, or no more than a finite number of finite discontinuities - this covers all signals in electronics. We will gloss over the distinction between periodic and non-periodic signals, as this is supposed to be about the basics.
If you want to argue about AC and DC you must understand Fourier. This is why I said that textbooks start with simple half-truths.
Right. According to Fourier DC does exist in our imagination only, since it does not exist during infinite long time. Also, no sine wave AC exists, since no current on the Earth can be supplied by power station during infinite long period of time.
Supplies of electricity always fooled consumers! I knew that! Let's sue them!
Supplies of electricity always fooled consumers! I knew that! Let's sue them!
Yes, the next complication is that DC usually covers slowly changing things too. Then you realise that the universe has not existed long enough to get pure DC. So everything is AC, but nothing is truly periodic. This is the mess we get in when someone tries to be pedantic about basic ideas.
Let me try this. DC is signal components with frequencies below epsilon Hz, where epsilon is a small number, of the same order of magnitude as 1/tau where tau is the time I take to measure or think about the circuit. All other signal components are AC. Can we agree on this definition, then try to explain it to the OP?
Let me try this. DC is signal components with frequencies below epsilon Hz, where epsilon is a small number, of the same order of magnitude as 1/tau where tau is the time I take to measure or think about the circuit. All other signal components are AC. Can we agree on this definition, then try to explain it to the OP?
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