Power supply connectors

[Conor Turton]

*Both* ends of a string must be connected together for it to be considered
a parallel circuit. In PC drive strings, only the PSU side of the strings
are connected together. The device ends are not, thus the voltage drops in
each string can be quite different.

**** are you stupid. A parallel circuit is where more than one
component has the +ve side connected to the +ve and the -ve side
connected to the -ve. Both ends do NOT have to be connected together.
Have you actually got any qualifications ni electronics becayuse all
you're doing is posting crap that a 13 year old would know was rubbish.

 

[Conor Turton]

Oh? And you have developed splitters whose connectors are free of
any voltage drops? Even a slight 10 mV drop per connector would result
in a 1 volt drop on 50 splitters (0.5v drop on the positive side, 0.5v
drop on the common side.)

Go away little boy until you actually have a clue.

 

[Conor Turton]

*Both* ends of a string must be connected together for it to be considered
a parallel circuit. In PC drive strings, only the PSU side of the strings
are connected together. The device ends are not, thus the voltage drops in
each string can be quite different.

May I suggest a you claim a refund from whoever taught you?

 

[W7TI]

**** are you stupid. A parallel circuit is where more than one
component has the +ve side connected to the +ve and the -ve side
connected to the -ve. Both ends do NOT have to be connected together.
Have you actually got any qualifications ni electronics becayuse all
you're doing is posting crap that a 13 year old would know was rubbish.

_________________________________________________________

Sorry Conor, he's correct.

Imagine two PSU strings, one drawing current, the other none. At the
END of each string, the voltages will be different, just as the man
said. Only where the two strings are connected together INSIDE the PSU
will the voltages be the same.

Conor, you owe the man an apology. Let's see if you're man enough to
admit you're wrong.

And get a spell checker.

 

[Ralph Mowery]

Oh? And you have developed splitters whose connectors are free of

Go away little boy until you actually have a clue.

Did you ever take time to measure the drop ? I measured .022 volt drop on
the 5 volt line after going through 2 Y connectors with the last one
connected to two old hard drives of about 2 gb. While the meter I used is
not lab grade , it was calibrated about a year ago against whatever the old
NBS turned into and is a 4 1/2 digit meter.
One amp has about 20 milivolts drop per foot for 20 guage wire which seems
to be about the size of the wire used. There is probably more voltage
lossed in the wire than the connectors.

 

[ric]

If you think half an amp is high current then God help you.

Hmmm...don't remember saying it was. Funny, but you didn't quote me as
saying that, but infer it instead.

And I don't think God is too worried about current definitions.

 

[ric]

**** are you stupid. A parallel circuit is where more than one
component has the +ve side connected to the +ve and the -ve side
connected to the -ve. Both ends do NOT have to be connected together.

Simply incorrect. Two devices that may have different voltages across
them are NOT connected in parallel. Drives that are connected to different
strings likely have a different voltage across them, and are NOT connected
in parallel. How can one drive with 11.985 volts across it be considered to
be in parallel with one with 11.885 volts across it? They can't be because
they aren't.

Have you actually got any qualifications ni electronics becayuse all
you're doing is posting crap that a 13 year old would know was rubbish.

Speaking from experience, are ya?

EE from Cal Berkeley, Class of 1978. And you?

 

[ric]

Go away little boy until you actually have a clue.

Nice comeback. Too bad you can't dispute the math.

[Birdwatchers, be on the lookout for a Redfaced Conor.]

 

[ric]

Did you ever take time to measure the drop ? I measured .022 volt drop on
the 5 volt line after going through 2 Y connectors with the last one
connected to two old hard drives of about 2 gb.

Gee, 22 mV drop for 2 connectors. That's almost exactly the same as my 10mV
drop per connector. Now, figure out the drop on Conor's stated 50 splitters.




While the meter I used is

 

[Conor Turton]

_________________________________________________________

Sorry Conor, he's correct.

Imagine two PSU strings, one drawing current, the other none. At the
END of each string, the voltages will be different, just as the man
said. Only where the two strings are connected together INSIDE the PSU
will the voltages be the same.

FOR GODS SAKE unless you're coming near the capacity of the wire, the
voltage drop will be so insignificant as not to be worth bothering
about. As a normal PSU is at least +/- 10% on any rail I wouldn't be
bothering myself with a 0.05V drop would you?

Conor, you owe the man an apology. Let's see if you're man enough to
admit you're wrong.

No I'm not.

And get a spell checker.

THey're called typos you sad twat. Only idiots use a spellchecker.

Some ****ing people on this planet need to get out more an GET A LIFE.
A drop of 0.5V even over the whole line IS NOT GOIN TO STOP THE ****ING
THING WORKING.

Perhaps you'd like to take your head out of your arse, get your face
out of those books and go see how things work in the real world.

 

[Conor Turton]

Did you ever take time to measure the drop ? I measured .022 volt drop on
the 5 volt line after going through 2 Y connectors with the last one
connected to two old hard drives of about 2 gb. While the meter I used is
not lab grade , it was calibrated about a year ago against whatever the old
NBS turned into and is a 4 1/2 digit meter.
One amp has about 20 milivolts drop per foot for 20 guage wire which seems
to be about the size of the wire used. There is probably more voltage
lossed in the wire than the connectors.

And of course a .022V drop will stop the drive from working won't it?
No, it won't SO WHAT THE **** IS THE POINT IN WORRYING ABOUT IT?

 

[Conor Turton]

Gee, 22 mV drop for 2 connectors. That's almost exactly the same as my 10mV
drop per connector. Now, figure out the drop on Conor's stated 50 splitters.

0.5V. Wow, that'll stop a drive from working...NOT.

 

[Conor Turton]

Nice comeback. Too bad you can't dispute the math.

Which is irrelevent for the probklem being discussed as it doesn't
matter one gnats bollock. Even if it were a 0.5V drop over the whole
lot it wouldn't be the cause of a device not working.

 

[ric]

FOR GODS SAKE unless you're coming near the capacity of the wire, the
voltage drop will be so insignificant as not to be worth bothering
about. As a normal PSU is at least +/- 10% on any rail I wouldn't be
bothering myself with a 0.05V drop would you?

ATX specifications are +/- 5% for the +5v and +12v. So, you're
wrong again. Keep humoring us, though.

http://www.formfactors.org/developer\specs\ATX12V_1_3dg.pdf

Some ****ing people on this planet need to get out more an GET A LIFE.
A drop of 0.5V even over the whole line IS NOT GOIN TO STOP THE ****ING
THING WORKING.

If the PSU +12v is set at 11.7 (well in spec) a drop of 0.5v will result
in 11.2v at the device. This can and does cause drive recognition problems
in many systems. It is not a case of work/not work. It is a case of reliably
working without glitches. If 11.2v were not a problem, the spec would not
be +/- 5%.

 

[R. Asby Dragon]

Some ****ing people on this planet need to get out more an GET A LIFE.
A drop of 0.5V even over the whole line IS NOT GOIN TO STOP THE ****ING
THING WORKING.

Perhaps you'd like to take your head out of your arse, get your face
out of those books and go see how things work in the real world.

Conor-- right now you _are_ Jack Shit !

You want real world?? Here's some...been dere dun dat. 40 years of electronics
enough??

Try crappy Molex crimps on one of those "strings" ; voltage drop on the 5V
rail at the end was over 1V with 3 heavy SCSI drives ; front case fan stated
getting gummy and caused erratic read/write when the room AC came on and the
cold air caused the fan to slow down and draw more current.

Cheesy 99 cent power wye --- caused CDR to burn coasters when any load was
placed on the baymount USB powered hub on the other side of the wye.

Early LS120 drives go weird if the 5v goes below 4.75 V AT THE CONNECTOR..

It's not just DC either; some devices feed spikes back that can cause problems.
I found a CDROM that would put back about .7V P-P at erratic rates when spinning
an out-of balance disc and scramble writes on a Zip drive on the same "string".

Non-PC but same type of problem:
Motor-driven siren in fire engine would "spike" back and cause 2way radio to
change channels and data terminal to lock up or reboot ... not good !!

I'm building a new PC slowly; and the first big change is to replace all the bay
leads with my own custom ones built to length with ferrite beads and decoupling
capacitors for each device. .

 

[W7TI]

A drop of 0.5V even over the whole line IS NOT GOIN TO STOP THE ****ING
THING WORKING.

Perhaps you'd like to take your head out of your arse, get your face
out of those books and go see how things work in the real world.

_________________________________________________________

Nobody said it would quit working. We were just pointing out your
incorrect understanding of voltage drops and parallel circuits.

As far as how things work in the real world, us guys who understand how
circuits REALLY work have much more success than folks like you who only
guess.

 

[larrymoencurly]

If the PSU +12v is set at 11.7 (well in spec) a drop of 0.5v
will result in 11.2v at the device. This can and does cause
drive recognition problems in many systems.

With my Soyo 810i integrated mobo and 466 MHz CPU, it kept the HD from
even spinning. The problem was that this equipment didn't draw enough
current for the particular PSU