Hi everybody,

I would like to convert my old DELL KH624 PSU to a lab power supply with variable output.
DELL PN = KH624
Manufacturer = LITEON
Manufacturer PN = PS-6371-1DF2-LF

Does anyone have the schematic ?
Thanks before, regards
Christian

 

Easier if you open it up and look what the chip number is, then get datasheet for it.

Post pics of the inside. .

 

Easier if you open it up and look what the chip number is, then get datasheet for it.

Post pics of the inside. .

The chip is a PS224 from SITI.

 

Datasheet link.. .

https://www.google.com/url?sa=t&sou...FjAAegQIAxAB&5falFwjfaq12-nXecTyWl_5falFwjfaq

This chip monitors the current and voltages on the 3, 5, 12 v lines, you will need to disable the voltage sense inputs.

 

Datasheet link.. .

https://www.google.com/url?sa=t&sou...FjAAegQIAxAB&5falFwjfaq12-nXecTyWl_5falFwjfaq

This chip monitors the current and voltages on the 3, 5, 12 v lines, you will need to disable the voltage sense inputs.

Thanks for you reply, but I was already able to get the PS224 datasheet.
I plan to change some resistors to decrease the voltage routed to over/under voltage protection input pins
In fact, I am looking for the whole PSU drawing to apply changes to the output stage

 

I think there must be another chip in the psu, this one doesn't make the pwm, it just monitors the Voltages. .

 

I think there must be another chip in the psu, this one doesn't make the pwm, it just monitors the Voltages. .

After a closer look, found 2 other chips :
One UC3843 PWM controller
One TNY267 switcher
Datasheet got but not yet able to see if they are used for separate voltage paths or worked together.
Any clue about getting the psu drawing ?
Thanks before.

 

Both of those chips are smps pwm controllers, using an opto coupler and possibly a TL431 zener to set the output voltage.
As for the drawing , unless you can find a web site offering circuits for free, which is highly unlikely, you will have to contact dell,.