Re: IBM Power Supply to IIe or IIgs : tech questions

[ekblaw@vnet.ibm.com (Rick Ekblaw)]

In <4h82u3$dqh@lynx.unm.edu>, buggie@musca.unm.edu (stephen e buggie) writes:
>
*snip*
>Do you get the full 150 watts of capacity by connecting to P8 and P9?

In many PC-style power supplies, each voltage is coming from only a single
source inside the power supply.  Better supplies list the maximum supplied
amperage for each voltage, as well as the overall wattage.  For example,
with your 150W supply, the breakout might be 16 amps for the +5V section
(80W), 4 amps for the +12V section (48W), 2 amps for the -5V section (10W),
and 1 amp for the -12V section (12W).  Depending on the size of the supply
wires, a single wire would probably be sufficient for all but the +5V section,
which would require 2.
>
>2. The 6-wire motherboard connectors on P8 and P9 look flimsy; will they 
>carry the full 150 watts?   Will it be better to solder the wires, rather 
>than to seek the male plug that mates to that style of connector?
>
>3.  Where can I buy the male 6-pin plug that mates to P8 or P9?  Does 
>Digi-Key or Jameco carry this plug?   What is it called (part no????)
>
>4.  Will more power be obtained by grouping in parallel the wires of the 
>same color?   They all have the same measured voltages.
>

On a good PC-style supply, the P8 and P9 connectors are not flimsy.  If yours are
cheap, you would probably be better served by cutting them off and replacing
them with the appropriate connector for your machine.  An easy and cheap way
to get the male connectors would be to salvage them off an old unwanted
IBM-type motherboard.  As I mentioned above, you would use more than one wire
to "spread the load (amperage)", depending on the size of the supply wires.

A word of warning:  Virtually all switching power supplies require a minimum load
to keep them from slowly cooking themselves.  Better supplies list the minimum
load requirements, and they also sense voltage/current conditions that are out of
range and shut themselves down.  Cheaper supplies do not protect themselves.
Just cooking the power supply is annoying... when the cooked supply takes your
//gs motherboard with it, that would be *very annoying*.  Be careful.

Rick