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Electronic conventions I hate

Discussion in 'General Electronics Chat' started by carbonzit, Sep 20, 2011.

  1. Sceadwian

    Sceadwian Banned

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    Regardless of personal opinions on the need or validity of the change, it is however is an SI unit so arguing about it is pointless in and of itself.
     
  2. carbonzit

    carbonzit Active Member

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    It sounds as if you're still trying to defend your position (that the unit called the Siemens was not formerly called the "mho'), when you are, in fact, wrong about this.

    If that's what you are defending, then you're simply incorrect. If we're somehow misunderstanding what you're writing, that's another matter.

    The point is simple: the unit that measures conductance (the reciprocal of resistance) was called the mho (ohm spelled backwards for those who may have missed it) for many decades. Then, some people on some scientific committee somewhere decided to rename it to the "Siemens". It's the same unit, only renamed.

    So are you saying this isn't so? Or are you trying to make some other point?
     
  3. Sceadwian

    Sceadwian Banned

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    The point is that if you use SI units of conductance it's Siemens, what was used before is irrelevant as it's not standard now, anything else is a personal opinion and really irrelevant to what is currently considered standard. Was the change in terminology needed or required? No, and the unit may have stayed the same, whatever collection of people's that chose to call it the Siemens decided to honor a historically active scientist in the field of electrical and thermal systems (as well as telegraphy)

    Get over it =)
     
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  4. dave

    Dave New Member

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  5. carbonzit

    carbonzit Active Member

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    So basically you're saying "Get over it. Quitcherbellyachin'. Shaddup. Get with the program."

    Replace that comma with a period, and that's exactly the point some of us were trying to make! The change was completely arbitrary, unnecessary, and had nothing whatever to do with SI units, neat powers-of-10 ordering or anything else.

    The unit DID stay exactly the same. 1/R.
     
    Last edited: Oct 9, 2011
  6. Sceadwian

    Sceadwian Banned

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    No it did not, because the mho was never an SI unit. The siemens currently is. The term mho was a popular convention before then not a standard and the siemens existed before as an artifact based version of the existing SI non artifact based unit.

    The reason we decided to call resistance ohm's is in fact based on the artifact based nature of the siemens unit at the time, it was redefined as the simple 1/R equation at the same conference which declared it as the SI standard. The reason I'm saying anything at all is because this is not about convention, or common use, it is about what is considered standard.
     
    Last edited: Oct 9, 2011
  7. carbonzit

    carbonzit Active Member

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    ????? If you can explain what that means in plain English, I'll pay you ten bucks and eat my hat.
     
  8. Sceadwian

    Sceadwian Banned

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    http://www.tech-faq.com/siemens.html

    http://www.sizes.com/units/siemens.htm
     
  9. Reloadron

    Reloadron Well-Known Member Most Helpful Member

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    Alas the poor Mho gone forever. Does it really matter. It was nice as Ohm spelled backwards is Mho, pretty simple. Really matters not because anyone should know the reciprocal of resistance is conductance and visa verse. Years ago when I learned Ohms Law I learned E was equal to I*R and now it is taught as V is equal to I*R. So what does it matter? As long as it is understood that the voltage is equal to the resistance multiplied by the current it really matters not. So does it really matter that Siemens are the unit of conductance verse Mhos? I learned things one way and they changed, the same holding true for current flow. The point is in reality and practical application it matters not. It becomes a game of semantics for those pedantic about naming conventions more than anything of value as to solving the equation. Granted just my take on it but I try to look at both sides as in before and now.

    By the way, so about the Solar System. What's the deal with Pluto? Someone decided it was too small to qualify? I learned 9 planets. Suddenly after all those years and all those school test there are only 8 planets? Someone decided that Pluto (like the Mho) was out?

    Just My Take and MY Opinion
    Ron
     
  10. carbonzit

    carbonzit Active Member

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    Well, Ron, maybe you can take heart from something I found at one of the links that Sceadwian posted:

    I wonder what areas of electronics those are? Maybe ones practiced by old geezers like some of us?

    Perhaps we can't do anything about these matters, as such decisions are handed out from on high, and all us peons can do is follow them. But we don't have to like it. This thread, like it or not, is all about complaining about such matters. It's something a lot of us humans like to do. So sue us.
     
  11. Reloadron

    Reloadron Well-Known Member Most Helpful Member

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    Hey CZ how goes it?

    Well quite simply I figure it this way. My educational years of electronics were during the late 50s and the 60s. I learned things in a set fashion and the way I learned it has put beanies and weenies on the table for almost 40 years. I survived 40 years with 2 ex wives and three kids. I was able to educate those kids all doing it the way I learned it.

    Considering it began with vacuum tubes (or valves for my friends across the pond) matters not. I adapted to tubes, transistors, and into today. Today when I sit with old friends, many dating back over 50 years and we joke around I say "Electronics have been very, very, good to me", and smile. Back then they thought my ham radio **** was weird. :) So yeah, trons have been good to me.

    Changes were bound to happen. When someone said 10 kc we knew it meant 10,000 cycles per second even though as was mentioned it did not define it to cycles per second. Thus KHz was born so Hertz could have his place in the scheme of things and be immortalized. OK, so it better defined it but did it really matter? Nope as I saw it as cycles per second the way I learned it so if you want to call it Hz for the simple mind, cool with me.

    If I see a radio dial labeled in Kilo Cycles or Kilo Hertz really matters not to me. I know what is meant and interpret accordingly. The same is true of Ohms Law and other formulas. It matters not and that was the point of my post. That is why I said in my opinion.

    Just My Take
    Ron
     
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  12. unclejed613

    unclejed613 Well-Known Member

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    the curved plate is also the rotor in variable caps, with the straight one the stator. since the stator is usually grounded, the "function" of the curved plate was adapted to fixed caps with the usually grounded outer foil denoted as the curved plate. with monolithic caps, it would make sense to have two straight plates, but back in the days of typeset books, a publisher usually had one or the other type of cap symbol in inventory, so that's what got printed.

    the nXn format of component values was introduced in the 70's i think, and while it took a little getting used to, it is much better than trying to decypher a missing decimal point. the ddm or dddm format is just a numeric representation of the color code, so that's not difficult, and the dddm format tells me i'm looking at a 1% tolerance resistor, but it's best to use these particular formats on the components themselves, they get confusing on a schematic, but the nXn format is pretty clear. i really think there should be some way of telling a SMT component from a thru-hole on a schematic (at least in "mixed" boards), but that's because i'm an old fart and don't like searching a board for a component on a "mixed" board, only to discover it's on the solder side of the board where it's impossible to get a scope or meter probe in to it's leads while the unit is powered.

    and yes, i also hate upside down ground symbols..... even worse are the use of a ground as well as power supply lines (usually all in the same schematic) where the grounds and power rails are all denoted with a single line crossing the end of the "wire" (i.e. like a T). some of the best ones were where each supply rail was denoted with different shapes or polygons at the end of the wire, which really made things easier to trace.

    another one i love to hate is the new symbols for an ADC with the pointed side towards the input.... a simple box with ADC in it was fine
     
    Last edited: Oct 10, 2011
  13. unclejed613

    unclejed613 Well-Known Member

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    when i was in grade school we were taught Bernoulli's Law of the relation between pressure and velocity, now modern hydrodynamics has demoted it to Bernoulli's Principle....
     
    Last edited: Oct 10, 2011
  14. Sceadwian

    Sceadwian Banned

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    Might want to careful with that statement UncleJed, you can purchase non-polarized electrolytic capacitors. The symbol should refer to polarized/non-polarized only.
     
  15. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

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    Hmm, that sounds familiar....

     
  16. unclejed613

    unclejed613 Well-Known Member

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    also, somebody mentioned "conventional current"... actual electron current flows from negative to positive. "conventional" current predated Edison's discovery of the vacuum diode, and assumes current flows from positive to negative. this was based on visual observations of lightning striking the ground from a positively charged cloud. what is invisible (and high speed photography didn't exist in the 1700's) is the discharge of electrons from the ground to the cloud just before the visible flash.

    conventional current can be useful in explaining the behavior of transistors, and so it is still taught in that context. anybody who has worked with tubes knows which way the current actually flows.
     
  17. Sceadwian

    Sceadwian Banned

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    Sorry Derstrom, I sent an apology last night apparently it didn't post properly. UncleJed was not wrong it was carbonzits post that I meant to post in reference to. You're quote that
    Was in what post number in this thread?
     
  18. Sceadwian

    Sceadwian Banned

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    unclejed; ask the same question of someone working with chemistry or more raw physics. Conventional current notation is seldom used, it becomes REALLY complex in ionized fluid situations (chemistry)

    Whichever one you CHOSE to use, it can always be converted to the other.
     
    Last edited: Oct 12, 2011
  19. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

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    Hey, no worries :)

    That quote is from post #21
     
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