help on PC power supply mod.

[helirulz]

have been reading a lot on PC ATX power supply lately and everyone who mod. theirs all have a resistor on the +5V line.WHY???
What does it do?

[X34]

U lazy to search

Check out the link

http://www.daddyhobby.com/forum/showthread.php?s=&threadid=1499

[PhiBeR]

Check out the sticky in ths forum for the PS conversion..

IIRC,
The resistor on the 5V line adds a load to the PS.
This is coz the PS is a switching power supply, so having a load will help in stablizing the output power..

[helirulz]

Check out the sticky in ths forum for the PS conversion..

IIRC,
The resistor on the 5V line adds a load to the PS.
This is coz the PS is a switching power supply, so having a load will help in stablizing the output power..

Yeah..i know it stabilizes something but...WAT THING????
Do u mean to stabilize the output voltage from fluctuating eg. output voltage varies from 11.9-12.3V instead of 'clean' 12 V only
or maybe output current?(i thought i read that too much Amps wont harm,only voltage will)

[X34]

Yeah..i know it stabilizes something but...WAT THING????
Do u mean to stabilize the output voltage from fluctuating eg. output voltage varies from 11.9-12.3V instead of 'clean' 12 V only
or maybe output current?(i thought i read that too much Amps wont harm,only voltage will)

The computer PS has a built in safety feature, it would only the power up after it senses proper connection. For us to use it for charging, the system got to be tricked, the resistor does it.

Without tricking the PS, the output may have voltage but no amps, this is why the voltage fluctuates.

The good PS voltage for charger is > than 12v < 14v.

Hope it answers ur question.

[fleek]

Yeah..i know it stabilizes something but...WAT THING????
Do u mean to stabilize the output voltage from fluctuating eg. output voltage varies from 11.9-12.3V instead of 'clean' 12 V only
or maybe output current?(i thought i read that too much Amps wont harm,only voltage will)

An addition, because the computer PS provides power in conjunction, meaning that it is suppose to supply power to the 5V components as well as the higher voltage 12V components at the same time. If no load is present at the 5V line, a sensing PS will determine that it is in open state, will automatically reduce the current that it will deliver at the 12V supply line, or even completely cut off as well for fail safe.

Thus it is necessary for a load to be present at the 5V line to be operational.