it is very complex to bring a 14.4v pc power supply instead of 12v?

 

Do you mean increase the 12v to 14.4v?
Max.

 

yes

 

it is very complex to bring a 14.4v pc power supply instead of 12v?

A few have a pre set pot - otherwise its hunt the precision resistor divider time.

The el.ectrolytics on the 5V rails are usually rated 6.3V - so you have to keep an eye on how much that voltage rises or get ready to dodge projectile aluminium cans.

You might also trip the OVP - it used to be a quad comparator, but its a while since I looked in one.

 

If you mean increasing an Atx from 12V out to 14.4V out, then you have to first find out what chip is used then modify the feedback circuit, and fool the ovp which is usually set by resistors .

 

I have an atx I can cannibalize
inside I tracked a "SEC k832A KA7500B" chip

does anyone have any feedback?
tnx

 

That's a Ka7500 or TL494 same chip, easy to modify, the voltage sensing is on pins 1,2 or 15,16 and pin 4 is the shutdown(+5 for off, gnd for on) which is usually fed from a lm339 or lm324 op amp.

Here is an example of an Atx using this chip, it uses pins 1,2 for voltage sensing and pins 15,16 for overcurrent , you need to have a look inside you psu and see which other chips are installed and which pins are used as the voltage sensing.



To modify the psu pin 4 needs to be shorted to pin 7, and whichever pin is connected to the outputs with the resistors, (on here it's pin 1,) needs to have a 22K to 47K preset across the +12V rail with the wiper to that pin...note the 5 resistors on Pin 1, need to be removed and the preset put in place.

If your successful the output capacitors will be rated at 16V, will need to be changed to 25V.

 

I have an atx I can cannibalize
inside I tracked a "SEC k832A KA7500B" chip

does anyone have any feedback?
tnx

The KA7500 isn't exactly rare - the data sheet isn't hard to find. You can probably find schematics for various models - even if not the right one for yours, its still a handy guide.

 

unfortunately the power supply was not working,

I have another one available with the chip:
DWA104 N161 - 536 J3013,

is it possible to do something with this or do you need to look for another Ka7500?

 

unfortunately the power supply was not working,

I have another one available with the chip:
DWA104 N161 - 536 J3013,

is it possible to do something with this or do you need to look for another Ka7500?

AFAICR: The KA7500 is the same game plan as chips like the 494 and 3524 etc. Not pin compatible of course - but they all have more or less the same innards.