Talk:List of obsolete technological nomenclature

From Wikipedia, the free encyclopedia

At least one item on this list isn't obsolete. I happen to live in range of a television station, WCFE-TV in New York State that goes into closedown every night at 12:35 AM., after a playing of the national anthem. 20:42, 13 November 2006

Does Wikipedia policy allow the odd page with a more humorous, POV stance or do we have to stick totally to the rules? I suggest this page could be more fun to read if we don't Infilms 14:26, 17 September 2006 (UTC)

I'd suppose that the policy is fairly rigid. This article sticks out like a sore thumb with its un-encyclopaedic style.203.206.249.161 12:42, 22 September 2006 (UTC)

Fair enough. Set to it and formalise, fellow wikifolk Infilms 23:13, 26 September 2006 (UTC)

   "Alternator - Old term for an alternating current ("AC") generator. All mechanical electromagnetic generators produce alternating current(...)" 

As far as I know, this is NOT true as depending on the configuration of the generator it could as well produce continuous current.

Gilles

[edit] Alternators

What a load of semantic bickering.

As I understand it, "Generator" is the generic name for a device that converts mechanical energy into electrical energy. Now an "alternator" is one specific type of generator with an AC output. (I also heard once that a "dynamo" is a generator with a DC output, but I'm not 100% certain if this is the correct definition.)

To say that all generators produce alternating current (AC) is like saying all electric motors are AC motors, and that DC motors don't exist. A "DC motor" using this reasoning is just an AC motor with a built-in synchronized mechanical polarity inversion switch, aka the commutator.

Of course, we use the terms "DC motor" and "AC motor" to distinguish between those motors which require external AC power, and those motors which can run on external DC power and contain their own commutator or internal switching circuit to make the armature spin.

So back on the topic of generators, it is convenient to distinguish between those device which when rotated will output direct current (DC), and those which will output alternating current (AC).

In the automotive world, the terms "generator" and "alternator" were traditionally used to distinguish between the modern-day devices which contain a diode rectifier, and older devices (generally up to the 1950's or early 1960's) which used a commutator.

Granted, the SAE has a valid point in discouraging the use of the term "alternator" for the electrical generating device onboard most vehicles. After all, the rectifier is internal, and the electrical output from the self-contained device is DC. Why should we make a nomenclature distinction between solid state electronic rectification and mechanical switching for rectification purposes? After all, we accept that motors with commutators and brushless motors with internally electronically switched coils are both still "DC motors".

But to say that the term "alternator" is meaningless and does not distinguish anything is simply incorrect. Perhaps for vehicles the term should only be used when the diode rectifier is an external device, and therefore the generating device alone outputs AC. (Though I have never seen a vehicle built like this, since it would be more expensive to manufacture and offers no advantages to built-in diodes.)

However, I do think the term "alternator" is appropriate for the generators in large electrical power plants, since these devices do not have any rectifiers and they output AC. In fact, the alternating current is of particular importance here since these generators are connected directly and synchronized to the distributed utility AC power.

The small generators that power some bicycle lights could also be correctly called alternators, since they all generate AC. These generators are simply a rotating magnet surrounted by a fixed coil. (Commutators and brushes would wear out too quickly and add unnecessary expense. Diode rectifiers would add unnecessary expense, along with slip rings and brushes that will still eventually wear out. And there is no practical advantage to running the light bulbs on DC instead of AC.)

-Justin Frim