tidying up wires

  • Thread starter Thread starter JEH
  • Start date Start date
J

JEH

Any reason not to use insulated automotive crimp type wire connectors on
power supply wires to shorten them? Any better options?
Thanks
John.
 
JEH said:
Any reason not to use insulated automotive crimp type wire connectors on
power supply wires to shorten them? Any better options?
Thanks
John.
Click to expand...

Parts for Mini-Fit Jr are here. This is a page from one of the older
Mouser catalogs. Use the part numbers from here, to search the Mouser
site for current pricing.

http://www.mouser.com/catalog/625/1082.pdf

The Mini-Fit Jr part numbers, are referenced in the ATX power supply
specs, in the section describing the connectors. Note that some of
the part numbers here, are out of date, and you'd have a hard time
figuring out what part on molex.com is a substitute.

http://web.archive.org/web/20030424...org/developer/specs/atx/ATX_ATX12V_PS_1_1.pdf
http://www.formfactors.org/developer/specs/atx/ATX12V_1_3dg.pdf
http://www.formfactors.org/developer/specs/ATX12V_PSDG_2_2_public_br2.pdf

All that you really need is some crimp pins. There are extractor tools
that slide over a Mini-Fit Jr pin, and compress the barbs. Then
the pin can be backed out of the shell. So you don't have to ruin
a shell, to work with it. (Note - I've never used the extraction
tool. So I'm only guessing at its function. If you buy nylon shells,
then you don't need to bother with extraction - just cut the whole
thing off.) [Manual line wrap to suit my USENET server...]

http://www.molex.com/cgi-bin/bv/mol...sp?fileName=/apptool/insert_extract_home.htm&
BV_SessionID=@@@@1267019171.1187736343@@@@&BV_EngineID=cccdaddlkigjgegcflgcehedffgdfmk.0

Jameco advertises a crimper and an extractor, but I'm not certain
whether their extractor is the right sized one or not.

http://www.robotstore.com/store/Default.asp?catid=1625&page=2

Newark has a page here, as another example. Newark carries many
obscure things, but has high prices compared to others.

http://www.newark.com/jsp/level5/module.jsp?moduleId=en_US/10426.xml

Note that, if you extract all the wires, snip exactly the same amount
of wire off each of the wires, before stripping and re-terminating
the wire with a new pin. If you don't, you'll get excess wire that
will bulge from the sides of the bundle of wires. It is not a
matter of snipping all the wires so they are flush on the ends -
the wires are probably slightly different lengths, to compensate
for the pin location in the main ATX connector.

Changing the wiring will void the warranty on the PSU, so if it is
a $200+ unit, that represents a fair liability. Someone else might
be pissed, if they are robbed of a multi-year warranty on the
PSU. If this is your own computer, then go right ahead.

Doing this properly, means no added voltage drop along the
cable, and no danger of something coming apart later. A
fresh crimp pin has nice springy barbs, and will fit securely
in place.

Note that, on the main ATX connector, one of the pins has two
wires in it. The fat wire carries the current. The thin wire is
a feedback wire, carrying a sample of voltage back to the PSU
controller. By sampling the voltage, the function is one or
"remote sense", and that helps compensate for voltage drop
in the cable. Make sure to put both wires into the new crimp
pin, so it continues to function properly. If the thin wire is
missed out, either the voltage will be low, or the PSU will go
nuts. At least one brand of PSU, has feedback wires on three pins,
and again, be careful to keep those pairs of wires together
when installing onto a fresh pin. Make sure the connector is
wired exactly the same when you're finished.

Paul
 
Paul said:
JEH said:
Any reason not to use insulated automotive crimp type wire connectors
on power supply wires to shorten them? Any better options?
Thanks
John.
Click to expand...

Parts for Mini-Fit Jr are here. This is a page from one of the older
Mouser catalogs. Use the part numbers from here, to search the Mouser
site for current pricing.

http://www.mouser.com/catalog/625/1082.pdf

The Mini-Fit Jr part numbers, are referenced in the ATX power supply
specs, in the section describing the connectors. Note that some of
the part numbers here, are out of date, and you'd have a hard time
figuring out what part on molex.com is a substitute.

http://web.archive.org/web/20030424...org/developer/specs/atx/ATX_ATX12V_PS_1_1.pdf

http://www.formfactors.org/developer/specs/atx/ATX12V_1_3dg.pdf
http://www.formfactors.org/developer/specs/ATX12V_PSDG_2_2_public_br2.pdf

All that you really need is some crimp pins. There are extractor tools
that slide over a Mini-Fit Jr pin, and compress the barbs. Then
the pin can be backed out of the shell. So you don't have to ruin
a shell, to work with it. (Note - I've never used the extraction
tool. So I'm only guessing at its function. If you buy nylon shells,
then you don't need to bother with extraction - just cut the whole
thing off.) [Manual line wrap to suit my USENET server...]

http://www.molex.com/cgi-bin/bv/mol...sp?fileName=/apptool/insert_extract_home.htm&


BV_SessionID=@@@@1267019171.1187736343@@@@&BV_EngineID=cccdaddlkigjgegcflgcehedffgdfmk.0


Jameco advertises a crimper and an extractor, but I'm not certain
whether their extractor is the right sized one or not.

http://www.robotstore.com/store/Default.asp?catid=1625&page=2

Newark has a page here, as another example. Newark carries many
obscure things, but has high prices compared to others.

http://www.newark.com/jsp/level5/module.jsp?moduleId=en_US/10426.xml

Note that, if you extract all the wires, snip exactly the same amount
of wire off each of the wires, before stripping and re-terminating
the wire with a new pin. If you don't, you'll get excess wire that
will bulge from the sides of the bundle of wires. It is not a
matter of snipping all the wires so they are flush on the ends -
the wires are probably slightly different lengths, to compensate
for the pin location in the main ATX connector.

Changing the wiring will void the warranty on the PSU, so if it is
a $200+ unit, that represents a fair liability. Someone else might
be pissed, if they are robbed of a multi-year warranty on the
PSU. If this is your own computer, then go right ahead.

Doing this properly, means no added voltage drop along the
cable, and no danger of something coming apart later. A
fresh crimp pin has nice springy barbs, and will fit securely
in place.

Note that, on the main ATX connector, one of the pins has two
wires in it. The fat wire carries the current. The thin wire is
a feedback wire, carrying a sample of voltage back to the PSU
controller. By sampling the voltage, the function is one or
"remote sense", and that helps compensate for voltage drop
in the cable. Make sure to put both wires into the new crimp
pin, so it continues to function properly. If the thin wire is
missed out, either the voltage will be low, or the PSU will go
nuts. At least one brand of PSU, has feedback wires on three pins,
and again, be careful to keep those pairs of wires together
when installing onto a fresh pin. Make sure the connector is
wired exactly the same when you're finished.

Paul
Click to expand...

Thanks Paul
 
Any reason not to use insulated automotive crimp type wire connectors on
power supply wires to shorten them? Any better options?
Thanks
John.
Click to expand...

I cut the wires in a staggered fashion, ie I cut adjacent wires at
different points so as not to risk shorting them. I then strip the
ends, slide some heatshrink tubing over them, twist the wires
together, and flow some solder over the join. I then use a hair dryer
on the tubing.

A better option would be to shorten the wires and resolder them at the
PCB end inside the PSU.

- Franc Zabkar
 
Franc said:
I cut the wires in a staggered fashion, ie I cut adjacent wires at
different points so as not to risk shorting them. I then strip the
ends, slide some heatshrink tubing over them, twist the wires
together, and flow some solder over the join. I then use a hair dryer
on the tubing.

A better option would be to shorten the wires and resolder them at the
PCB end inside the PSU.

- Franc Zabkar
Click to expand...

makes my idea look archaeic!!

cut the wires that were too long.. soldered the wires then good old black
electrical tape..

granted i heated it slightly to get it to shrink.... but didnt use no fancy
gozmos and crimpers etc..

regards dave
..
 
JEH said:
Any reason not to use insulated automotive crimp type wire connectors on
power supply wires to shorten them? Any better options?
Click to expand...

The only thing I can think of is that a crimp is a lot fatter than a
wire, meaning if you put a lot of crimps in the same place, the cable
can become really bulky. So you may want to stagger them to prevent
this, or make solder connections with heatshrink tubing over them.

I'm so cheap that i'd probably just shorten the wires at the circuit
board, but that requires a soldering iron rated for at least 40-45W to
melt the heavy solder. Also if a single strand of wire doesn't go
into the hole, it can create a short (tin the wires first).
 
The only thing I can think of is that a crimp is a lot fatter than a
wire, meaning if you put a lot of crimps in the same place, the cable
can become really bulky. So you may want to stagger them to prevent
this, or make solder connections with heatshrink tubing over them.

I'm so cheap that i'd probably just shorten the wires at the circuit
board, but that requires a soldering iron rated for at least 40-45W to
melt the heavy solder. Also if a single strand of wire doesn't go
into the hole, it can create a short (tin the wires first).
Click to expand...

Just cut them. Always the best way to tidy up.
 
larry said:
The only thing I can think of is that a crimp is a lot fatter than a
wire, meaning if you put a lot of crimps in the same place, the cable
can become really bulky. So you may want to stagger them to prevent
this, or make solder connections with heatshrink tubing over them.

I'm so cheap that i'd probably just shorten the wires at the circuit
board, but that requires a soldering iron rated for at least 40-45W to
melt the heavy solder. Also if a single strand of wire doesn't go
into the hole, it can create a short (tin the wires first).
Click to expand...
I did use some automotive crimps in my last project--seemed to do ok (my
computer is still working anyway). I had this 420W PSU (forget the
brand) with a harness that would probably fit an 8 ft tower. The crimps
seemed to work ok and weren't too ugly. I did stagger cut them
too--that did help. Used lots of wire ties. I think I like the "just
cut them" and use "black electrical tape" ideas also. Maybe some red
duct tape in a pinch? :-)
 
JEH said:
Any reason not to use insulated automotive crimp type wire connectors on
power supply wires to shorten them? Any better options?
Thanks
John.
Click to expand...
If you are never going to change anything that uses power that would
probably work but there are also plastic devices that bundle the wires
together so they are not so messy.
 
If you are never going to change anything that uses power that would
probably work but there are also plastic devices that bundle the wires
together so they are not so messy.
Click to expand...


I use the wire ties, although these must be cut and replaced. For
heavier cables I use Velcro strips which I also use for the theater
room cabling.
 
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