Archived from groups: alt.comp.periphs.mainboard.asus,alt.windows98,alt.comp.periphs.mainboard.abit,alt.comp.periphs.mainboard.msi-microstar,alt.comp.periphs.mainboard.gigabyte (
More info?)
Oh, that proves my technical knowledge is as poor as my
English spelling! Thank you for point out my mistakes!
Well, I'm glad to participate in these newsgroups, you guys
ensure me that there still exist some people who knows
electronics (and circuit theory). One of my teachers in
college tried to convince me to stop playing with
electronics (analog and digital) but concentrate on
programming. That happened some ten years ago. Most
youngsters today don't make small projects, be it an audio
amplifier, or a digital quiz machine. That's what I did
when I was young.
Try to do some tricks in analog world gives me as much fun
as to write a decent program / algorithm. Much better than
what I have to do in ERP/HRMS/Web to earn a living now.
Those stupid programs made me remember grandma Grace Hopper!
Okay, enough OT, back to Asus/Gigabyte/MSI reality now. I
wonder how come an one cm square CPU die can consume 100W
power, that means tens of ampere (if voltage is 1.5V +/-
0.2V). That must be crazy. My good old days' 2N3055/MJ2955
cannot take so much power, but enough to make me deaf
through a pair of speakers. And my school teachers told me
that up to a few hunder megahertz, there's no need to use a
conductor, just a pair of close enough wires will let
signals jump across. Well, how come the microwave range GHz
running processor can still work accurately, but not act
like a mesh antenna? And IBM is so proud of her Copper
Interconnect. Wouldn't it be better to be called Air
Interconnect?
Stephen Wong @ Hong Kong
On Wed, 21 Apr 2004, Paul wrote:
> In article <Pine.LNX.4.58.0404221042080.10086@localhost.localdomain>,
> Stephen SM WONG <wongsm@netvigator.com> wrote:
>
> > Oh pals, as English is not my first language, I won't mind
> > too much to be blamed on poor spelling! In order to learn
> > something, so, I go to "dictionary.yahoo.com" and search for
> > "analog" and "analogue". I'm sure Yahoo's dictionary is
> > nothing as prestige as Oxford's, Longman's or Webster's, but
> > anyway, "analog" and "analogue" are two forms of the same
> > word.
> >
> > Well, I did make a big mistake in my article, and it's more
> > technical. It's about the resistance of an analog
> > voltmeter. I'd digged out my old and reliable Sanwa
> > YX-360TR multimeter (an analog one), and the DC50V range has
> > a resistance of 20kohm. But common digital multimeter (like
> > a Sanwa PM10) has DCV resistance of megaohms. So, I was
> > wrong, as long as the voltmeter has a much higher resistance
> > compare with the internal resistance of the power source,
> > the voltmeter can be used. In modern days PC power supply,
> > the internal resistance should be very low, say, < 1 ohm, a
> > 20kohm (analog) voltmeter is good enough to measure the
> > potential difference. Okay, enough technical stuff, go back
> > to party!
> >
> > Stephen Wong @ Hong Kong
> >
>
> That brings back memories for me. When I was a kid, I couldn't
> afford a real multimeter, and instead I bought a surplus
> bare meter movement (just the part with the analog needle on
> it).
>
> The meter movement is actually a current measuring device,
> and the smaller the current needed to drive it to full scale,
> the more sensitive it is. Before there were "buffered"
> analog or "buffered" digital meters, all you had in a meter
> was a resistor to set the scale and the meter movement.
> This is what I used as my voltmeter...
> ___
> + / \ -
> <-------- R = V_fullscale ---------| |------>
> ----------- \___/
> I_fullscale
>
> So, some example values. If the meter movement needed 50
> microamps to cause the needle to go to its max reading,
> this is termed a sensitivity of 20Kohms/volt. To make a
> meter that reads 1V full scale, you would stick R=20K
> as the series resistor. If you wanted the meter instead
> to be a 50V full scale meter, then R=1Megohm would be the
> choice to make. A handful of precision resistors and
> you are all set.
>
> The point of this story, is to point out that the load
> from that kind of meter actually changes depending on
> what scale the meter is set to. My meter was terrible
> for measuring small voltages.
>
> With analog and digital meters today, they have a
> buffer stage on the input, so the characteristics
> aren't quite the same. Much less current is needed on
> the input, to make the voltmeter work, and you don't have
> to worry about the loading like you used to with the
> simple minded design above. But my meter didn't need
> any batteries to make it work.
>
> Paul
>
Facebook
Twitter
Instagram