Proof Reading for "Gas Discharge Tubes" Article

Discussion in 'Feedback and Suggestions' started by PAFMC01, Mar 20, 2013.

  1. PAFMC01

    Thread Starter New Member

    Mar 20, 2013
    3
    0
    PROOF READ COPY OF ARTICLE ON "GAS DISCHARGE TUBES", WITH CORRECTIONS, SUGGESTIONS AND COMMENTS


    Usage I believe is wrong or could be improved in RED. Comments in BLUE
    Article not quoted in full because of Thread length restrictions


    If you've ever witnessed ...... voltages at bay, huge surges of current travel between opposing poles of electrical charge which we call "lightning." :mad:

    It's not the opposing poles of electrical charge that are called lightning!
    Better construction would be:
    huge surges of current which we call "lightning", travel between opposing poles of electrical charge.

    The buildup of high voltages by wind and rain is a fairly continuous process, the rate of charge accumulation increasing under the proper atmospheric


    is a fairly continuous process, and the rate of charge accumulation increases under the proper atmospheric....

    Actually it is not necessarily the RATE of charge accumulation that increases - only the charge accumulation. Similar distinction between velocity and acceleration.



    conditions. However, lightning bolts are anything but continuous: they exist as .....lightning bolts? The answer lies in the nonlinear (and hysteric):eek:

    Arghhh! Should be HYSTERETIC not hysteric - that has a totally different meaning! Writer uses hysteretic later on correctly.


    resistance of air.
    Under ordinary conditions, air has an extremely high amount:mad: of resistance. Nah... just say "has an extremely high resistance..." It is so high, in fact, that we typically treat its resistance as infinite and electrical conduction through the air as negligible.



    Tiny quibble: if the resistance is INFINITE then the current is ZERO not just negligible. If the resistance were only very very very high, then we might consider the current as negligible.



    The presence of water and dust in air lowers ....... Plasma is a relatively good conductor of electricity, its specific resistance being much lower than that of the same substance in its gaseous state.

    Nice and precise use of the term specific resistance, though "resistivity" is the more usual term - but that may be a regional difference in usage.



    As an electric current moves through the plasma, there is energy dissipated in the plasma in the form of ........

    voltage reaches the threshold voltage of the lamp, the lamp suddenly "turns on" No need for inverted commas. This is not a euphemistic usage as in 'The dude was "turned on" by the gear he smoked'
    Same applies to the usage below: "turns off". You don't ever say the switch was "turned on" ...at least not in an electronics forum (...that's a joke for the kinky) You just say "the switch was turned on"



    and quickly discharges the capacitor to a low voltage value. Once discharged, the lamp "turns off" (get rid of the quotation marks) and allows the capacitor to build up a charge once more. The result is a series of brief flashes of light from the lamp, the rate of which is dictated by battery voltage, resistor resistance, capacitor capacitance, and lamp threshold voltage.
    While gas-discharge lamps are more commonly used as sources of illumination, their hysteric HYSTERETIC properties were leveraged in slightly more sophisticated variants known as thyratron tubes. Essentially a gas-filled triode tube (a triode that being a three-element vacuum electron tube performing much a similar function to the N-channel, D-type IGFET), suggestion: if you are not going to explain what an N-channel depletion type IGFET is, then don't refer to it. It confuses the reader, and let's face it, if they knew what an igfet was, let alone the channel and mode variations, they wouldn't need to be reading an introduction to hysteresis. My suggestion for reducing obfuscation is:


    Essentially a gas-filled triode tube (that being a three-electrode vacuum tube) the thyratron could be turned on with ....


    the thyratron tube could be turned on with a small control voltage applied ......the load's power source is AC, which provides a clue about how the thyratron turns off after its been triggered on: since AC

    better would be ... after it's been triggered on. Since AC voltage periodically passes....

    That is, full stop (period). New sentence. And an apostrophe needed because "it's" is a contraction of "it has".



    voltage periodically ........

    to its normal "off" state. Appropriate use of apostrophes here - don't change it

    ....where it first turned on, continuing to conduct until there:mad: delete this word the supply voltage drops off to almost zero volts. Because thyratron tubes are one-way (diode) devices,

    You have previously gone to some lengths to explain a thyratron is a TRIODE device - now you are saying it is a DIODE! Better might be:

    "Because a thyratron tube is a uni-directional conductor....
    "
    no voltage develops across the load through the negative half-cycle of AC.

    In practical thyratron circuits, multiple tubes arranged in some form of full-wave rectifier circuit to facilitate full-wave DC power to the load.Delete this par...not relevant to the main topic. I think it is pretty well accepted that full wave rectifiers produce full wave DC rectification!

    AND... thyratrons have not been practical since the 1950's!! You address that issue later, but as it stands, you seem to be saying there is such a thing as a practical thyratron circuit. Ho Ho Ho!

    The thyratron tube has been applied to a relaxation oscillator circuit.
    Not really - it is an integral part of the R-O circuit...without it the R-O does not exist, so it cannot be said to be "applied" to a relaxation oscillator circuit. Possibly clearer is "The thyratron tube has been applied to FORM a relaxation oscillator circuit.

    I speak of thyratron tubes in the past tense for good reason: modern semiconductor components have obsoleted :mad::mad: double ARGGHH. There is no verb "to obsolete" so there cannot be a past tense of the form "obsoleted". Correct usage is "to make obsolete" or "to render obsolete".

    The nastiest exemplar of this trend is the pseudo verb "to trial"... as in, Big Pharma trialled a new drug...
    There is no verb "to trial". Trial exists only as a noun. However, the verb usage is so common these days that it is becoming accepted into the language, and soon that particular linguistic horror will become an accepted form.

    How would you like someone to enverbiate* the word "salad" and come up with "For lunch, he saladed all the green leaves he could find"

    * Don't fret about about this one - it's my own invention. It will come to mean "to turn a noun into a verb"

    thyratron tube technology ..........

    of semiconductor components does much the same thing: use hysteretically and this is the first correct use of the adjectival form found, but I am not sure about where the rest of the sentence is going. use switch current on and off. It is these modern devices that we now turn our attention to.

    • Simple oscillator circuits called relaxation oscillators may be created with nothing more than a resistor-capacitor charging network and a hysteretic YAY!!! device connected across the capacitor.

    MY SUMMARY:
    Excellent and technically accurate article explaining the basics of lightning, hysteresis, and sundry devices exhibiting that property.



    Perhaps digresses too much from the central theme of "gas discharge" but I liked the meander into ancient history like thyratrons. Possibly could afford to tie all relaxation oscillators in together with a discussion of negative resistance, which is a key and necessary element of any relaxation osc. Besides, neg-R is a novel concept to most newbies, but a useful one.



    Would have liked to see mention that the only?? contemporary uses of gas discharge devices are as high power street lamps (sodium vapour,* mercury vapour) and in miniature devices as lightning or surge arrestors for overhead telecommunications lines. I suppose the good old fluorescent tube lamp is another very common and still current example.

    Sorry I could not quote the article in full but the forum has length restrictions

    * yes I know - American usage is "vapor". English/Australian usage is "vapour" Both are right - but only in their home territories!

    Nice one Author.

    Regards
    PAFMC01

     
  2. Georacer

    Moderator

    Nov 25, 2009
    5,142
    1,266
    Thank you for your extensive review!

    I 'm sure the book editor will take it into account.
     
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