A Windows XP help forum. PCbanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » PCbanter forum » Microsoft Windows XP » General XP issues or comments
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

[OT] Trying to Find the "how to connect"l guide of an NS30/35/36-FS motherboard



 
 
Thread Tools Display Modes
  #1  
Old May 2nd 20, 04:42 PM posted to microsoft.public.windowsxp.general
R.Wieser
external usenet poster
 
Posts: 1,111
Default [OT] Trying to Find the "how to connect"l guide of an NS30/35/36-FS motherboard

Hello all,

I've been given an old tower made by Fujitsu-Siemens, with an NS30/35/36-FS
rev-C2 motherboard inside, which seems to have been made by a company named
DFI.

I have already found some data about it (max processor speed, type of memory
used, etc), but I'm missing one important part: the physical layout of all
connectors, and especially the description of the pins of the headers (onto
which the frontpanel stuff - buttons, leds, etc - is connected).

I've ofcourse also tried to search the DFI companies site, but probably due
to the motherboards age (2003) the info (and downloads) for it seems to have
been purged. :-(

tl;dr:
Does anyone know or have (a link to) the "how to connect" guide to an
"NS30/35/36-FS" (rev-C2) motherboard for me ? TIA.

Regards,
Rudy Wieser


Ads
  #2  
Old May 2nd 20, 08:50 PM posted to microsoft.public.windowsxp.general
Paul[_32_]
external usenet poster
 
Posts: 10,864
Default [OT] Trying to Find the "how to connect"l guide of an NS30/35/36-FSmotherboard

R.Wieser wrote:
Hello all,

I've been given an old tower made by Fujitsu-Siemens, with an NS30/35/36-FS
rev-C2 motherboard inside, which seems to have been made by a company named
DFI.

I have already found some data about it (max processor speed, type of memory
used, etc), but I'm missing one important part: the physical layout of all
connectors, and especially the description of the pins of the headers (onto
which the frontpanel stuff - buttons, leds, etc - is connected).

I've ofcourse also tried to search the DFI companies site, but probably due
to the motherboards age (2003) the info (and downloads) for it seems to have
been purged. :-(

tl;dr:
Does anyone know or have (a link to) the "how to connect" guide to an
"NS30/35/36-FS" (rev-C2) motherboard for me ? TIA.

Regards,
Rudy Wieser


Time for the multimeter I'm afraid.

You're in Smithsonian country.

I'd get all excited, but Google search is useless right now.
Google and Bing used to give almost equal results. Now,
bing.com is beating them a bit in terms of pages returned.

Google used to do "load shedding", which is why I had to tell
people occasionally it could take 24 hours to find a breadcrumb
for them. It's a lot worse now.

*******

Bing.com gave me this for example. I'm not expecting to find
your exact board, and the purpose of showing this is to
"show what DFI was thinking".

https://www.manualslib.com/manual/10...?page=7#manual

Front panel header example.

https://www.manualslib.com/manual/10...page=20#manual

Note that ODM boards, made by DFI for FS, do not have to
follow retail motherboard conventions. A retail motherboard
from the era might have up to 20 pins for the panel header.
Whereas ODM standards are to use an 8 pin pattern, with PWR/RST/IDELED/PWRLED
type functions.

On page 20 for example, pins 3,4,5,6,7,8,9,10 are the
ODM subset of pins. Two switches, two LEDs. DFI could simply not put
header pins into the other holes, to satisfy FS as a customer.

And the Green Switch might be a Sleep button, but I can't
be sure of that. PCs have had more than two switches on the
front, but I don't know what that was for. They also had
Power LED, IDE LED, as well as Message LED, where Message LED
might have lit up when an email poll picks up new mail. I don't
think I've owned a PC with that on it :-)

Paul
  #3  
Old May 2nd 20, 09:08 PM posted to microsoft.public.windowsxp.general
J. P. Gilliver (John)[_7_]
external usenet poster
 
Posts: 468
Default [OT] Trying to Find the "how to connect"l guide of an NS30/35/36-FS motherboard

On Sat, 2 May 2020 at 15:50:27, Paul wrote:
[]
And the Green Switch might be a Sleep button, but I can't
be sure of that. PCs have had more than two switches on the
front, but I don't know what that was for. They also had
Power LED, IDE LED, as well as Message LED, where Message LED
might have lit up when an email poll picks up new mail. I don't
think I've owned a PC with that on it :-)

Paul


I've never had (or even seen, I think!) a PC with a message LED.

Two buttons: well, going _really_ far back (I _think_ to AT rather than
ATX, but there _might_ have been overlap): the other one was usually
labelled "Turbo", and controlled processor speed. (Sometimes there was a
two-digit LED display showing the MHz; I don't think I ever saw one
where there really was a counter, I think the switch just switched
segments, as well as the processor speed!) Anyone who had such a PC
nearly always ran it at the faster speed, of course. I believe when
faster (!) PCs _first_ appeared, the switch was there to reduce the
processor clock to the original PC clock speed, so that any software
that actually expected that (there allegedly was some such software -
maybe clocks before they started putting a cheap watch chip on the
motherboard? I don't know [oh, hang on - I think it was also some games,
which ran too fast if the processor did]), but on most of the PCs I
encountered that _did_ have a "Turbo" switch, _both_ speeds available
were faster than the original PC clock speed. (Which I think was some
commonly-available crystal - NTSC colour subcarrier or something? 4.77
MHz rings a bell, though I thought NTSC colour was three point
something.)
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)[email protected]+H+Sh0!:`)DNAf

'It works for me' is not the same as it isn't broke - Kenn Villegas, 2010-2-19
in
https://rwmj.wordpress.com/2010/02/1...egistry-sucks-
technically/
  #4  
Old May 3rd 20, 01:25 AM posted to microsoft.public.windowsxp.general
Paul[_32_]
external usenet poster
 
Posts: 10,864
Default [OT] Trying to Find the "how to connect"l guide of an NS30/35/36-FSmotherboard

J. P. Gilliver (John) wrote:
On Sat, 2 May 2020 at 15:50:27, Paul wrote:
[]
And the Green Switch might be a Sleep button, but I can't
be sure of that. PCs have had more than two switches on the
front, but I don't know what that was for. They also had
Power LED, IDE LED, as well as Message LED, where Message LED
might have lit up when an email poll picks up new mail. I don't
think I've owned a PC with that on it :-)

Paul


I've never had (or even seen, I think!) a PC with a message LED.

Two buttons: well, going _really_ far back (I _think_ to AT rather than
ATX, but there _might_ have been overlap): the other one was usually
labelled "Turbo", and controlled processor speed. (Sometimes there was a
two-digit LED display showing the MHz; I don't think I ever saw one
where there really was a counter, I think the switch just switched
segments, as well as the processor speed!) Anyone who had such a PC
nearly always ran it at the faster speed, of course. I believe when
faster (!) PCs _first_ appeared, the switch was there to reduce the
processor clock to the original PC clock speed, so that any software
that actually expected that (there allegedly was some such software -
maybe clocks before they started putting a cheap watch chip on the
motherboard? I don't know [oh, hang on - I think it was also some games,
which ran too fast if the processor did]), but on most of the PCs I
encountered that _did_ have a "Turbo" switch, _both_ speeds available
were faster than the original PC clock speed. (Which I think was some
commonly-available crystal - NTSC colour subcarrier or something? 4.77
MHz rings a bell, though I thought NTSC colour was three point something.)


I've never had an AT era machine here. Completely missed it.

I think the AT missed out on Soft Power. They didn't have
the button on the front. Just a button on the back. When you
saw "It's safe to turn off your PC" on the VGA screen,
you reached for the switch on the back to pack it up for the night.

You can see the AT power cable pair, with the pins that go 1-6, 1-6
for a total of 12 pins, there is no PS_ON# like on ATX.
There's no 3.3V either (likely some 5V chips back in the day).

http://www.playtool.com/pages/psucon...onnectors.html

1 orange power good
2 red +5 volts or connector key
3 yellow +12 volts
4 blue -12 volts
5 black ground
6 black ground
1 black ground
2 black ground
3 white -5 volts
4 red +5 volts
5 red +5 volts
6 red +5 volts

And my first PC had "one-phase power" on the motherboard,
the CPU was that weak and unassuming. It ran 300MHz,
until you changed the setup and then it ran 450Mhz,
and you'd go "so what?" :-) That's because RAM was
so bad back then, it ran 300MB/sec, or a bit slower
than your SSD today. And the hard drive did 10MB/sec
(as fast as a cheap SD card today).

Paul
  #5  
Old May 3rd 20, 03:49 AM posted to microsoft.public.windowsxp.general
J. P. Gilliver (John)[_7_]
external usenet poster
 
Posts: 468
Default [OT] Trying to Find the "how to connect"l guide of an NS30/35/36-FS motherboard

On Sat, 2 May 2020 at 20:25:42, Paul wrote:
[]
I've never had an AT era machine here. Completely missed it.


Oh, the original AT - and XT - machines were very satisfying: big cast
(or possibly machined, I'm not sure) cases!

I think the AT missed out on Soft Power. They didn't have
the button on the front. Just a button on the back. When you
saw "It's safe to turn off your PC" on the VGA screen,
you reached for the switch on the back to pack it up for the night.


The really early machines, definitely: big red lever switch on the side.
You definitely knew that was a power switch! However, some towers were
AT era and had the power switch on the front; you could tell as it was a
two-position switch, in for on.

having just looked at an old tower, I've remembered another reason some
cases had two buttons on the front: some had a reset button. I always
felt nervous about that: too easy to hit by mistake! IMO if you're going
to have a reset button, it should always be two in series.

You can see the AT power cable pair, with the pins that go 1-6, 1-6
for a total of 12 pins, there is no PS_ON# like on ATX.
There's no 3.3V either (likely some 5V chips back in the day).

http://www.playtool.com/pages/psucon...onnectors.html

1 orange power good
2 red +5 volts or connector key
3 yellow +12 volts
4 blue -12 volts
5 black ground
6 black ground
1 black ground
2 black ground
3 white -5 volts
4 red +5 volts
5 red +5 volts
6 red +5 volts

And my first PC had "one-phase power" on the motherboard,
the CPU was that weak and unassuming. It ran 300MHz,
until you changed the setup and then it ran 450Mhz,
and you'd go "so what?" :-) That's because RAM was
so bad back then, it ran 300MB/sec, or a bit slower
than your SSD today. And the hard drive did 10MB/sec
(as fast as a cheap SD card today).

Paul


My first PC (after defecting from a different family of processors) was
a 386SX; 25 or 40 or something like that MHz.
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)[email protected]+H+Sh0!:`)DNAf

We no longer make things, but sell each other consultancy on how to run
consulatancies better. (Michael Cross, Computing 1999-3-4 [p. 28].)
  #6  
Old May 3rd 20, 09:01 AM posted to microsoft.public.windowsxp.general
R.Wieser
external usenet poster
 
Posts: 1,111
Default [OT] Trying to Find the "how to connect"l guide of an NS30/35/36-FS motherboard

Paul,

Time for the multimeter I'm afraid.

You're in Smithsonian country.


My apologies, I forgot to mention its still connected & working. I just
don't want to go yank the connections without knowing where they belong - I
am/was intending to move the board into another case.

I'd get all excited, but Google search is useless right now.


I did, and again found that out. :-( Not that DDG did any better (less
cruft though).

Bing.com gave me this for example. I'm not expecting to find your exact
board, and the purpose of showing this is to "show what DFI was thinking".


:-) All I see there is the names of motherboard related connectors randomly
strewn over a white page. A nice example of how /not/ to convert a PDF.

Note that ODM boards, made by DFI for FS,


Facepalm. That "for FS" only now made me realise that thee "-FS" on the
end of the motherboard ID is short for "Fujitsu-Siemens".

do not have to follow retail motherboard conventions.


Which is, to me, another good reason to get the exact specs. Although
none of the frontpanel stuff is going to supply current on those pins,
connecting two output pins to a simple LED will be confusing. Worse:
connecting the powerbutton over them could destroy either pin. :-(

Thanks for the searching and links though.

Regards,
Rudy Wieser


  #7  
Old May 3rd 20, 10:03 AM posted to microsoft.public.windowsxp.general
R.Wieser
external usenet poster
 
Posts: 1,111
Default [OT] Trying to Find the "how to connect"l guide of an NS30/35/36-FS motherboard

I've been given an old tower made by Fujitsu-Siemens, with an
NS30/35/36-FS rev-C2 motherboard inside, which seems to have been made by
a company named DFI.


I just found the towers model name, embossed black-on-black (almost
invisible) on the front right side: it seems to be a "Scaleo 600". Alas,
it seems to have been sold with different motherboards and the found "users
manual" is written for exactly them, users (no mentioning of the wiring of
the motherboard).

Regards,
Rudy Wieser


  #8  
Old May 3rd 20, 02:09 PM posted to microsoft.public.windowsxp.general
J. P. Gilliver (John)[_7_]
external usenet poster
 
Posts: 468
Default [OT] Trying to Find the "how to connect"l guide of an NS30/35/36-FS motherboard

On Sun, 3 May 2020 at 10:01:36, R.Wieser wrote:
[]
My apologies, I forgot to mention its still connected & working. I just
don't want to go yank the connections without knowing where they belong - I
am/was intending to move the board into another case.

[]
Ah. At least you can then sketch them as you unplug. (Remember - if
there are no omitted pins or other such indication - to note the
orientation of the connector[s]!) Only things that won't be obvious is
the orientation of the LEDs, which you can _probably_ determine with a
multimeter (most multimeters will light an LED, though you might need to
shade it to see it [perhaps excluding blue ones, but XP-era machines
_probably_ won't have those]).
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)[email protected]+H+Sh0!:`)DNAf

If a cluttered desk is characteristic of a cluttered mind, what does an empty
desk mean ?
  #9  
Old May 3rd 20, 03:28 PM posted to microsoft.public.windowsxp.general
R.Wieser
external usenet poster
 
Posts: 1,111
Default [OT] Trying to Find the "how to connect"l guide of an NS30/35/36-FS motherboard

John,

Ah. At least you can then sketch them as you unplug.


Indeed. I found the front panel header (the most important one because of
the multiple connectors being plugged onto it ) due to the non-standard
usage and the omnious scribblings under them. 20-pins with pin 11 broken
out. Alas, those scribblings do not make it clear which pins are actually
used. As such I've only been to identify the connected ones (the power and
HD leds and ofcourse the power switch), but no such luck for the "reset"
"G-led"(?) and "speaker" markings.

I've already tried to match them up with some standard configurations, but
have not been able to find a match.

Most of the other headers are boxed with slotting and all of different size,
so not that easy to mix them up. The only one I have to jot down are the to
dual USB headers. Althoug later versions can be inserted in either
orientation, these ones do not look like them (10 pin, last two pins not
used).

That leaves a few small 4, 3 and 2 pin slotted headers that currently are
not used. Could make some guesses about them related to their forms &
location, but thats perhaps for a later time.

(Remember - if there are no omitted pins or other such indication - to
note the orientation of the connector[s]!)


:-) I noted down the color of the wires going to each pin.

Only things that won't be obvious is the orientation of the LEDs, which
you can _probably_ determine with a multimeter (most multimeters will
light an LED


Yup, especially when the multimeter has a "diode" position in its ohms
range. Though normally I just plugged the "new" leds in and checked if
they would light up. If not I reversed their polarity. Hasn't failed me
yet. :-)

Thanks for the suggestions.

Regards,
Rudy Wieser


  #10  
Old May 3rd 20, 08:16 PM posted to microsoft.public.windowsxp.general
J. P. Gilliver (John)[_7_]
external usenet poster
 
Posts: 468
Default [OT] Trying to Find the "how to connect"l guide of an NS30/35/36-FS motherboard

On Sun, 3 May 2020 at 16:28:35, R.Wieser wrote:
John,

Ah. At least you can then sketch them as you unplug.


Indeed. I found the front panel header (the most important one because of
the multiple connectors being plugged onto it ) due to the non-standard
usage and the omnious scribblings under them. 20-pins with pin 11 broken


Probably not a bad idea - if they aren't already - to label the leads on
the old case, assuming you're not scrapping it.

out. Alas, those scribblings do not make it clear which pins are actually
used. As such I've only been to identify the connected ones (the power and
HD leds and ofcourse the power switch), but no such luck for the "reset"
"G-led"(?) and "speaker" markings.


The speaker plug is nearly always - always IME - a 4 by 1 connector,
with the wires only in the end ones (usually no actual connectors in the
middle two).

I've already tried to match them up with some standard configurations, but
have not been able to find a match.

Most of the other headers are boxed with slotting and all of different size,
so not that easy to mix them up. The only one I have to jot down are the to
dual USB headers. Althoug later versions can be inserted in either
orientation, these ones do not look like them (10 pin, last two pins not
used).


Sometimes they are two identical ports side-by-side. (USB2 is only four
pins.)

That leaves a few small 4, 3 and 2 pin slotted headers that currently are
not used. Could make some guesses about them related to their forms &
location, but thats perhaps for a later time.


Small ones, I'd guess might be for case fans, or audio in/out, as you
say, depending on location.

(Remember - if there are no omitted pins or other such indication - to
note the orientation of the connector[s]!)


:-) I noted down the color of the wires going to each pin.


I don't know if there is any standard for case LED/switch wires! (In any
one case, one side of the LEDs is usually the same colour, but I don't
know if they're always the same between different cases.)

Only things that won't be obvious is the orientation of the LEDs, which
you can _probably_ determine with a multimeter (most multimeters will
light an LED


Yup, especially when the multimeter has a "diode" position in its ohms
range. Though normally I just plugged the "new" leds in and checked if
they would light up. If not I reversed their polarity. Hasn't failed me
yet. :-)


Yes, there's usually a series resistor, so shouldn't _damage_ them the
wrong way round.

Thanks for the suggestions.


YW.

Regards,
Rudy Wieser


--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)[email protected]+H+Sh0!:`)DNAf

We have now sunk to a depth at which restatement of the obvious is the first
duty of intelligent men. In times of universal deceit, telling the truth will
be a revolutionary act - Orwell
  #11  
Old May 3rd 20, 09:17 PM posted to microsoft.public.windowsxp.general
R.Wieser
external usenet poster
 
Posts: 1,111
Default [OT] Trying to Find the "how to connect"l guide of an NS30/35/36-FS motherboard

John,

Probably not a bad idea - if they aren't already - to label the leads on
the old case, assuming you're not scrapping it.


That isn't a bad idea. Even though the reason I'm intending to take the
motherboard out is that I'm a bit vain, and the other case simply looks
better than the contemporary plastic-looking "Scaleo 600" one. In other
words, although the case is fully functional I'm probably not going to
re-use it. but, never say never.

The speaker plug is nearly always - always IME - a 4 by 1 connector,


Yup, thats what I remember too. Using a piezo tweeter to test (next to no
current) will show quickly enough where the connector needs to go.

Sometimes they are two identical ports side-by-side. (USB2 is only four
pins.)


Thats them. Though in a 2x5 configuration, both aligned to the left. As
opposed to a later 2x4 configuration with one row of connections going from
left-to-right and the other from right-to-left (iow, both orientations
work).

Small ones, I'd guess might be for case fans, or audio in/out, as you say,
depending on location.


Yep, also got that feeling. One might even be a WOL input one (connected
to a/the network card).

I don't know if there is any standard for case LED/switch wires!


I don't think so, but that way I can either, if needed, plug the connectors
back in the right way, or allow me to grab the wire and follow it back to
the front panel to see whats connected to it. Though the "scribblings" are
a good indication to their functions.

Yes, there's usually a series resistor, so shouldn't _damage_ them the
wrong way round.


? I thought that LEDs do not get damaged by putting them the wrong way
around. At least not when they are supposed to work when connected
correctly. They just behave like actual diodes and block the current. Or
has that changed since the old red ones ?

Regards,
Rudy Wieser


  #12  
Old May 4th 20, 01:45 AM posted to microsoft.public.windowsxp.general
J. P. Gilliver (John)[_7_]
external usenet poster
 
Posts: 468
Default [OT] Trying to Find the "how to connect"l guide of an NS30/35/36-FS motherboard

On Sun, 3 May 2020 at 22:17:51, R.Wieser wrote:
John,

Probably not a bad idea - if they aren't already - to label the leads on
the old case, assuming you're not scrapping it.


That isn't a bad idea. Even though the reason I'm intending to take the
motherboard out is that I'm a bit vain, and the other case simply looks
better than the contemporary plastic-looking "Scaleo 600" one. In other
words, although the case is fully functional I'm probably not going to
re-use it. but, never say never.


Well, even if you give it away.

The speaker plug is nearly always - always IME - a 4 by 1 connector,


Yup, thats what I remember too. Using a piezo tweeter to test (next to no
current) will show quickly enough where the connector needs to go.


Hmm. You'd have to have the mobo on and continually beeping; and I
wouldn't feel too happy poking round a live mobo with bare wires!

Sometimes they are two identical ports side-by-side. (USB2 is only four
pins.)


Thats them. Though in a 2x5 configuration, both aligned to the left. As
opposed to a later 2x4 configuration with one row of connections going from
left-to-right and the other from right-to-left (iow, both orientations
work).


Hmm. One side might, but I think not the other: you'd end up with +5 and
0 reversed, and I think the data lines too.

Small ones, I'd guess might be for case fans, or audio in/out, as you say,
depending on location.


Yep, also got that feeling. One might even be a WOL input one (connected
to a/the network card).


Right, hadn't thought of that - not something I know much about; I'd
vaguely assumed it didn't need extra connections.

I don't know if there is any standard for case LED/switch wires!


I don't think so, but that way I can either, if needed, plug the connectors
back in the right way, or allow me to grab the wire and follow it back to
the front panel to see whats connected to it. Though the "scribblings" are
a good indication to their functions.

Yes, there's usually a series resistor, so shouldn't _damage_ them the
wrong way round.


? I thought that LEDs do not get damaged by putting them the wrong way
around. At least not when they are supposed to work when connected
correctly. They just behave like actual diodes and block the current. Or


Yes, silly me. Although I think they tend to have a lower max. reverse
voltage than even the weediest signal diode, but it's still more than
their operating voltage. (Otherwise those back-to-back ones where two
colours are in the same package wouldn't be safe to themselves.)

has that changed since the old red ones ?


As a side shoot: I believe a red LED is actually a much better voltage
reference than a Zener of that sort of voltage rating: LV Zeners have
rather "soft" curves, whereas a red LED drops about 1.8 volts pretty
precisely over quite a broad range.

Regards,
Rudy Wieser


John
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)[email protected]+H+Sh0!:`)DNAf

"In the _car_-park? What are you doing there?" "Parking cars, what else does one
do in a car-park?" (First series, fit the fifth.)
  #13  
Old May 4th 20, 08:57 AM posted to microsoft.public.windowsxp.general
R.Wieser
external usenet poster
 
Posts: 1,111
Default [OT] Trying to Find the "how to connect"l guide of an NS30/35/36-FS motherboard

John,

Hmm. You'd have to have the mobo on and continually beeping; and I
wouldn't feel too happy poking round a live mobo with bare wires!


And neither would I. My thought was to take old connector with wires, wrap
the ends to the tweeters ones and tape them off (or something like that).
Probably would shut the 'puter down to move the connector to a new set of
pins. Me being a bit over-cautious ? Probably. :-)

Hmm. One side might, but I think not the other: you'd end up with +5 and 0
reversed, and I think the data lines too.


Nope, because thats the whole trick. :-) The two rows of pins on the
motherboard header are wired mirrored to each other*, so that you simply
cannot plug the (non-slotted) USB connector in a wrong orientation. Clever
guys them.

* think of two sets of connections in a circle. Just flattened.

Right, hadn't thought of that - not something I know much about; I'd
vaguely assumed it didn't need extra connections.


And AFAIK you would be assuming right. Nowerdays the WOL line is on the
card-edge connector, doing away with that cumbersome seperate cable.

Otherwise those back-to-back ones where two colours are in the same
package wouldn't be safe to themselves.


.... or the ones I we wired ourselves. I remember, when bi-colored leds
where stil pricy, soldering two flat ones together to get a squarish single
one.

As a side shoot: I believe a red LED is actually a much better voltage
reference than a Zener of that sort of voltage rating: LV Zeners have
rather "soft" curves, whereas a red LED drops about 1.8 volts pretty
precisely over quite a broad range.


I remember schematics which used a LED at the zener position. I always
assumed that it was for a "is the circuit powered" purpose though. Never
thought it would actualy work better than a purpose-build zener.

Regards,
Rudy Wieser


  #14  
Old May 4th 20, 08:41 PM posted to microsoft.public.windowsxp.general
J. P. Gilliver (John)[_7_]
external usenet poster
 
Posts: 468
Default [OT] Trying to Find the "how to connect"l guide of an NS30/35/36-FS motherboard

On Mon, 4 May 2020 at 09:57:57, R.Wieser wrote:
[]
Hmm. One side might, but I think not the other: you'd end up with +5 and 0
reversed, and I think the data lines too.


Nope, because thats the whole trick. :-) The two rows of pins on the
motherboard header are wired mirrored to each other*, so that you simply
cannot plug the (non-slotted) USB connector in a wrong orientation. Clever
guys them.

* think of two sets of connections in a circle. Just flattened.


Ah, we're talking at cross purposes; if a single header with two ports,
then indeed as you say. I think I've seen them where, although the mobo
connector is two row, the case had two single-row headers you plugged
onto the mobo header side by side, which obviously _could_ be done the
wrong way round.
[]
Otherwise those back-to-back ones where two colours are in the same
package wouldn't be safe to themselves.


... or the ones I we wired ourselves. I remember, when bi-colored leds
where stil pricy, soldering two flat ones together to get a squarish single
one.


They seem, these days (or three years or so when I "retired"), to be
becoming less common anyway: two-chip LEDs yes, but with three legs. I
suppose that does give you the option of having both chips on at once.
(or of course three- or even four-chip packages now.)

As a side shoot: I believe a red LED is actually a much better voltage
reference than a Zener of that sort of voltage rating: LV Zeners have
rather "soft" curves, whereas a red LED drops about 1.8 volts pretty
precisely over quite a broad range.


I remember schematics which used a LED at the zener position. I always
assumed that it was for a "is the circuit powered" purpose though. Never
thought it would actualy work better than a purpose-build zener.


I can't remember which parameters: either forward voltage against
current at a fixed temperature, or forward voltage at a fixed current
against temperature; it might even be different either side of the sweet
spot. I "know" (= vaguely remember!) that LEDs - red ones, at least -
(forward biased, i. e. on) were better than "conventional" Zeners
(reverse biased) in _some_ respect, at rated voltages below the sweet
spot. (Of course, only the one voltage is available!) IIRR, the sweet
spot for conventional Zeners (i. e. where the reverse voltage varied
least against whatever the other parameter was) is around the 5.6 volt
level. It's probably academic now, in that reference devices - even just
two-terminal - these days, are probably a fully-fledged IC inside the
package, not just a single device. Having the LEDs show the circuit was
powered was indeed also useful!

Regards,
Rudy Wieser


John
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)[email protected]+H+Sh0!:`)DNAf

At the age of 7, Julia Elizabeth Wells could sing notes only dogs could hear.
  #15  
Old May 4th 20, 09:23 PM posted to microsoft.public.windowsxp.general
R.Wieser
external usenet poster
 
Posts: 1,111
Default [OT] Trying to Find the "how to connect"l guide of an NS30/35/36-FS motherboard

John,

Ah, we're talking at cross purposes;

....
I think I've seen them where, although the mobo connector is two row


My bad, I can't remember having ever seen them in a single row pins.
Regardless, I should have directly mentioned a 2x5 header/connector instead
of starting with just "10 pins".

They seem, these days (or three years or so when I "retired"), to be
becoming less common anyway: two-chip LEDs yes, but with three legs.


Yup, still have a few of those. Athough you could keep toggeling the
polarity on the two-pin ones to mix colors the three-pin ones where way
easier - fire and forget. Than again, with almost every second chip being a
programmable controller of some kind it doesn't matter that much anymore.

I can't remember which parameters: either forward voltage against current
at a fixed temperature, or forward voltage at a fixed current against
temperature;


I must confess that I never went that deep into it. Have seen a few zener
curves on a 'scope ofcourse, but just for the "proof of the pudding", not
much else

Having the LEDs show the circuit was powered was indeed also useful!


True. But at some point I got enough of seeing them literally
/everywhere/ - with no possibility to switch them off without de-powering
the whole device. :-\

Regards,
Rudy Wieser


 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is Off
HTML code is Off






All times are GMT +1. The time now is 02:37 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Copyright 2004-2020 PCbanter.
The comments are property of their posters.