It may depend on the language you're using.There's no prescription in my native language about capitalization of those units, they are considered usual nouns therefore they don't get any capitalization at all in any of our school manuals.We need to know when we are talking about Hertz as a person or when we only count those hertz...
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There are rules, international rules for the writing of units. It is not a "trend".
The General Conference on Weights and Measures is the authority of the International Bureau of Weights and Measures, the inter-governmental organization established in 1875 under the terms of the Metre Convention through which member States act together on matters related to measurement science and measurement standards. (from wiki)
Among these, GCWM edict rules for the denominations and writings of the units.
The States then declares (or not) that these acts are official and must be obeyed.
The UK and the USA are members of the GCWM. These countries have special sections of the rules for their "awkward" measures.
China and Japan are also members of the GCWM.
And, like UK and USA, they have not declared the legality of the rules.
The vast majority of the other States in the world respect and have declared legal these rules.
The General Conference on Weights and Measures is the authority of the International Bureau of Weights and Measures, the inter-governmental organization established in 1875 under the terms of the Metre Convention through which member States act together on matters related to measurement science and measurement standards. (from wiki)
Among these, GCWM edict rules for the denominations and writings of the units.
The States then declares (or not) that these acts are official and must be obeyed.
The UK and the USA are members of the GCWM. These countries have special sections of the rules for their "awkward" measures.
China and Japan are also members of the GCWM.
And, like UK and USA, they have not declared the legality of the rules.
The vast majority of the other States in the world respect and have declared legal these rules.
I kinda have a feeling that actually you don't like this topic's existence and you purposely divert it to offtopic...I caught you and a few other friends of yours doing it for a few times and i think it's not fair what you do using your name to drive discussions away.I remember you blaming me of being a politician once...Who's really doing the politics here?
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With the M/m it get confusing.
MHZ (or MHz) is Hz x 10^6 and mHz is Hz x 10^-3.
Idem mΩ and MΩ a difference of x 10^9
Mona
Sorry but several people point to correct use of the writing of units. It is you that keeps writing standardised stuff not according easy international rules (Romania is also member of ISO). It makes making mistakes way easier if you don't follow simple electrical unit names. Many tech people get annoyed as they do follow these rules with a good purpose (also for you that is). If you want assistance then write stuff as intended.
Now you start being personal with "I caught you and a few of your friends". Before you know it race, color, religion etc. are involved.
Correct.
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I've a lot of time for this.
I've just picked up a mint, later Quad FM4 tuner (an obvious gap in my accumulation of 'nice fm tuners')
Anyway, after a good look at the schematic, a look inside it and a poke with the 'scope - anything on regulated rails comes off one 7812.aha... I thought. Except, of course: Quad.
The input ripple to the 7812 is under 70mV and totally clean, thanks in part to rectifier choice, mains input snubber matched to transformer, and a useful amount of secondary winding resistance for a good dab of RC by design. The 7812 output ripple & noise, well under 100uV.
Then all the RF ICs it feeds have local, discrete HF LC decoupling (Thank you, PJW); the one LF IC (the TCA4500 stereo decoder) uses RC very much along the lines you suggest; look there with an LF opamp preamp for scope probe - its well into into the 'neurotics-only' category on the supply pin - on a part with >55dB PSRR.
Points to be gained by meddling with the factory-standard: nil. And that is a good thing.
(having put my neuroses back in the box - can confirm it sounds excellent, and shall do for many years yet.)
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Well, that can only be proven when a low noise replacement for the 7812 is tried and measured. It won't have a detrimental effect anyway.
Quad FM4 is a nice tuner, too bad FM will be shut down here. Sold all my tuners as now DAB+ is the standard...
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just as a continuation to this subject:
Are you really fine with IC voltage regulators ?
Until now the nakamichi, no feedback loose regulator proved its benefits as it signaled immediately a voltage drop by 3v from 29v to 26v dc supplying the positive lm340 regulator which was drawing some 130ma more than the 7906 Maybe it was defective or reacted badly to the op-amp denoiser...i have no idea, I didn't consider i should have made further investigations so it was replaced with mct7805, adding two more 5v1 zeners to lift the gnd pin to 15v. Consequently the voltage quadrupler output voltage got down too by 5 or 6 v sensing 130ma more load.You have the whole working schematic of the +-20v regulator and a photo of the whole supply chain for the +-43v(quadrupler), +-29v(nakamichi no feedback reg), +-20v technics denoiser, +-10v tehnics denoiser loaded with 2 x 48 ohm resistors .I moved down the chain those 1 ohm current sensing resistors to check which regulator had problems .
Are you really fine with IC voltage regulators ?
Until now the nakamichi, no feedback loose regulator proved its benefits as it signaled immediately a voltage drop by 3v from 29v to 26v dc supplying the positive lm340 regulator which was drawing some 130ma more than the 7906 Maybe it was defective or reacted badly to the op-amp denoiser...i have no idea, I didn't consider i should have made further investigations so it was replaced with mct7805, adding two more 5v1 zeners to lift the gnd pin to 15v. Consequently the voltage quadrupler output voltage got down too by 5 or 6 v sensing 130ma more load.You have the whole working schematic of the +-20v regulator and a photo of the whole supply chain for the +-43v(quadrupler), +-29v(nakamichi no feedback reg), +-20v technics denoiser, +-10v tehnics denoiser loaded with 2 x 48 ohm resistors .I moved down the chain those 1 ohm current sensing resistors to check which regulator had problems .
Attachments
Hi All ! after many readings i think i have finally understood a very basic lesson. IC voltage regulators main function is to regulate voltage and they actually do this quite well.
What they instead do not do very well is to suppress ripple.
For this job very effective are capacitance multipliers. , and much more effective that simple LC/RC passive low pass filters for instance and with less issues of voltage drops along the rail.
I have discovered these very important circuits only recently. And they interest me a very lot.
So i would like to ask questions and get more info about these cap multipliers.
If they are treated already in some specific threads please redirect me there
One very important desision to make is the active devices to use.
It seems that mosfets are the device of choice followed by darlingtons and then bjts.
Can this be confirmed ? strangely enough i have seen only schematics using bjts and very few using darlingtons but no one using mosfets ?
My idea is to try to assembled a power supply like
1st rectification stage > cap multiplier (ripple suppressor) > standard IC regulator (fixed or variable)
Any advice on this very important circuit for me would be much welcome and appreciated.
Thanks again and have a nice day
and they actually do this quite well. What they instead do not do very well is to suppress ripple.
For this job very effective are capacitance multipliers. , and much more effective that simple LC/RC passive low pass filters for instance and with less issues of voltage drops along the rail.
I have discovered these very important circuits only recently. And they interest me a very lot.
So i would like to ask questions and get more info about these cap multipliers.
If they are treated already in some specific threads please redirect me there
One very important desision to make is the active devices to use.
It seems that mosfets are the device of choice followed by darlingtons and then bjts.
Can this be confirmed ? strangely enough i have seen only schematics using bjts and very few using darlingtons but no one using mosfets ?
My idea is to try to assembled a power supply like
1st rectification stage > cap multiplier (ripple suppressor) > standard IC regulator (fixed or variable)
Any advice on this very important circuit for me would be much welcome and appreciated.
Thanks again and have a nice day
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