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Thread: The switch from CPS to Hertz

  1. #1
    Old Timer Tom Phillips's Avatar
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    The switch from CPS to Hertz

    Attached is an excerpt from the June 1965 Hewlett Packard Journal that I just tripped across.
    I think it documents an interesting bit of electronics history.
    I would have guessed that the transition took place several years later. I just looked at some old textbooks and found that one printed in 1967 still used CPS. Another printed in 1972 stated "Scientific usage of cycles per second has recently been dropped in favor of the Hertz (Hz)."
    Regards,
    Tom
    Attached Thumbnails Attached Thumbnails jun-1965-hp-journal-hz-vs.-cps.jpg  

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    Senior Member Enzo's Avatar
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    I remember the transistional period as not sudden. I to this day sometimes will say "apply a 400 cycle note to the input..." But tried to make myself use Hertz. It took time for everyone to get onto the new name for cps. (I do recall cps as more common than c/s.)

    Just as the shift from mmf to uuf to pf took a while.


    In 1972, in the grand scheme of electronics history, six or seven years is still "recently."
    Education is what you're left with after you have forgotten what you have learned.

  3. #3
    rjb
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    I remember there was an announcement of the new "official" designation in Radio Electronics magazine, but I can't tell you what year.

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    Senior Member Enzo's Avatar
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    I remember when Popular Electronics got a bur under their saddle about "printed circuit." They insisted that a "printed circuit" was an integrated circuit chip, the circuit was printed in silicon on the chip. They insisted we refer to the pc board as an "etched circuit board." That lasted a while, then they eventually accepted that no one used etched circuit and everyone accepted printed circuit for pc boards. Guess we showed them...
    Education is what you're left with after you have forgotten what you have learned.

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    rjb
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    Wikipedia to the rescue:

    The hertz is named after the German physicist
    Heinrich Hertz (1857–1894), who made important scientific contributions to the study of electromagnetism. The name was established by the International Electrotechnical Commission (IEC) in 1930.[6] It was adopted by the General Conference on Weights and Measures (CGPM) (Conférence générale des poids et mesures) in 1960, replacing the previous name for the unit, cycles per second (cps), along with its related multiples, primarily kilocycles per second (kc/s) andmegacycles per second (Mc/s), and occasionally kilomegacycles per second (kMc/s). The term cycles per second was largely replaced by hertz by the 1970s.

    Hertz - Wikipedia, the free encyclopedia

  6. #6
    Noodle of Reality Steve Conner's Avatar
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    I thought printed circuits got their name because the very first experimental ones were screenprinted in silver ink.

    If PCBs are etched circuits, then so are ICs, because the manufacturing process is kind of similar. A mask is made on the silicon using photoresist, and things get deposited or etched through the holes in the mask. The last time I knew anything about this, there could be 10 or more processing steps, each requiring a different mask.
    "Enzo, I see that you replied parasitic oscillations. Is that a hypothesis? Or is that your amazing metal band I should check out?"

  7. #7
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    Yes.
    The first wide use of PCBs was military (WW2) and the first commercial use was ... listen to this ... an automated factory making very low cost electronic consumer goods (in that case radios) in huge amounts (3 radios per minute), practically untouched by human hands, to be sold in huge quantities at the other side of the World.
    So, what's news? It's happening every day !!! Are we talking about Behringer or something?

    Small detail: the factory was in England, the massively produced cheap radios were to be sold in Asia !!!
    The *exact* opposite of what's happening today.
    To read this fascinating (real) story:
    The project Sargrove
    Radio Robot Squirts Out 3 a Minute | Modern Mechanix
    Juan Manuel Fahey

  8. #8
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    Yes.
    The first wide use of PCBs was military (WW2) and the first commercial use was ... listen to this ... an automated factory making very low cost electronic consumer goods (in that case radios) in huge amounts (3 radios per minute), practically untouched by human hands, to be sold in huge quantities at the other side of the World.
    So, what's news? It's happening every day !!! Are we talking about Behringer or something?

    Small detail: the factory was in England, the massively produced cheap radios were to be sold in Asia !!!
    The *exact* opposite of what's happening today.
    To read this fascinating (real) story:
    The project Sargrove
    Radio Robot Squirts Out 3 a Minute | Modern Mechanix
    xlg_radio_robot_0.jpg
    xlg_radio_robot_1.jpg
    Juan Manuel Fahey

  9. #9
    Senior Member Enzo's Avatar
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    They may have decided in 1960, but we sure didn't all hop on the bandwagon with it the next day.


    Printed/etched... the whole controversy faded away. The magazine lost.


    The world operates on the metric system of measurements. The USA? Nah, we join Myanmar and Liberia in NOT using the metrics. How many hectares is your lawn?

    Of course here in the USA we have a lot of folks whose thoughts can be summed up as "I ain't going on no goddam metric system. Them foreigners can't shove that crap down our throats."
    Education is what you're left with after you have forgotten what you have learned.

  10. #10
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    Can somebody answer my doubt?
    I don't worry about old guys not switching (myself being a fine example of old guy ) for obvious reasons, but what's being taught in schools?
    Not whether the Metric system is taught or not, I'm sure it is, but what's being *used* when teaching other stuff?
    Teachers ask Timmy to calculate , say, the area of his yard in sq. yards or sq meters?
    City to city distances are taught in miles or Kilometers?
    And so on.
    If the old system is still used to *teach* ... then there's not the slightest intention to switch, no matter what they claim.
    Juan Manuel Fahey

  11. #11
    Noodle of Reality Steve Conner's Avatar
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    In the UK, school and university math, physics, and so on have used SI units for a while. I believe it came in around the same time as the currency went decimal, 1970-something. Mechanical engineering calculations are far easier in SI units, you aren't forever having to multiply by some factor to convert degrees Rankine to slugs per cubic fortnight.

    Petrol (gasoline?) is sold by the litre, but car fuel economy is measured in MPG, and imperial gallons at that. American cars have such bad fuel economy because the US gallon is slightly smaller. Coke comes in 2-litre bottles, but beer is sold in pints. The road signs give distances in miles, but the nuts and bolts holding them up, indeed all the nuts and bolts in the hardware store, have metric threads. Finally, the weight of a person is measured in "stone", one stone being 14lbs. I don't know if this is used anywhere else.

    My pet hate is PCB layout with a mixture of imperial and metric IC packages.
    Last edited by Steve Conner; 08-19-2012 at 09:48 AM.
    "Enzo, I see that you replied parasitic oscillations. Is that a hypothesis? Or is that your amazing metal band I should check out?"

  12. #12
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    Down with metric. Don't give an inch.



    A rose is a rose is a rose. Would that which we call a rose smell more like a burning resistor by any other name?

    I think I'm going to start a movement to change all distance measurements to multiples of the Planck length.

    Hmmm... Planck. Wasn't he someone? In a band maybe?

    Actually, given our experience here in the USA with presidents, we may start to call dictionaries "Clintons".

  13. #13
    Noodle of Reality Steve Conner's Avatar
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    All distance measurements are already multiples of the Planck length, just very large ones.

    Planck invented the solid-body guitar, sometimes known as a "plank" in his honour.
    "Enzo, I see that you replied parasitic oscillations. Is that a hypothesis? Or is that your amazing metal band I should check out?"

  14. #14
    Noodle of Reality Steve Conner's Avatar
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    All distance measurements are already multiples of the Planck length, just very large ones.

    Planck invented the solid-body guitar, sometimes known as a "plank" in his honour.
    "Enzo, I see that you replied parasitic oscillations. Is that a hypothesis? Or is that your amazing metal band I should check out?"

  15. #15
    Senior Member Enzo's Avatar
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    Ah, go plink your plank.
    Education is what you're left with after you have forgotten what you have learned.

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