PS3 model: APS-226 or APS-227, how to increase the voltage + 12V?

Hello

I found a schematic of a PS3 power supply on the network, probably APS-226 or APS-227.
The power supply gives 12V / 32A and 5V / 3A.
I am asking for tips on how to raise the power supply from + 12V to + 15V and more.

Thanks for any tips.

You do it on your own responsibility: you connect to R410 a 22K potentiometer set to max. and you slowly decrease.
You also need to change the Zenerka D401 to a higher voltage (OVP protection). As there will be no problems with increasing it, it is better not to exceed 16V because the electrolytic capacitors at the output may not like it ...

Thank you for the quick reply.

I'll try and let you know how it went.
As for the diode and electrolytic capacitors, I have already reached the same conclusions.
However, replacing electrolytic capacitors with higher voltage ones can be troublesome, due to the heat sink above them, so I will not touch them at first. I will replace the zener diode, raise the voltage to 14V and check the power supply under load.

Edit1:
I replaced the 13V zener diode with a regulated zener diode and set it to 15V.
I connected a 22K potentiometer to the R410 resistor.
After starting the power supply, I set the output voltage to 14.1V.
I loaded the power supply with a 6.6? resistor (current about 2A) and the output voltage increased to 14.5V. So the regulation works, but not as it should. The feedback is "too strong". I am asking for advice on how to correct it. Maybe increasing the R402 resistor will help?

Additionally, the R277 resistor, which preloads the 12V line, needs to be replaced with a stronger one.

Adam12127 wrote:

Maybe increasing the R402 resistor will help?

Probably the opposite.
It looks like IC401 is going into saturation (similar to the transistor). Unfortunately, we do not know the voltage value on it - please measure it.
It is also not known whether the system does not enter a state of instability (excitation). One should look at the oscillograms from the vicinity of the above-mentioned IC401, for example.

Adam12127 wrote:

I connected a 22k potentiometer to the R410 resistor.

It is worth adding, for example, 10K in series with him. That's in case the direction of rotation is confused.
I wonder what the stabilization looked like before the output voltage changed.
Does the variable component not appear on C224, 225, 232 during loading?

As for R277, it can be left on. The power on it will increase by about 36%, which will not exceed its rated power anyway. Error in the diagram in the RY101 control. Where does the RY signal come from? (This obviously has no effect on the 14V instability at the output)

Thank you mate WP for the response, at the moment the situation is as follows:

I unsoldered the potentiometer from the R410 resistor and disconnected the R277, R402, R407, C402 from the output (12V). I soldered a 39? resistor to the R277 and the output and connected the R402, R407, C402 to the created divider.

Regulated zener diode replaced with a regular 15V (D401).

Voltage at the output of the PSU:
a) without external load => 14.15V
b) at a current of about 2A => 14.35V
c) at 4A => 14.33V
d) at 8A => 14.30V

Voltages are measured immediately after switching on the power supply.

I did not test the behavior of the power supply during longer operation due to the lack of proper cooling of the resistors (2 x 3.3? / 50W) in the load.

There is no way to load the power supply more, but it seems that with higher currents it will also be OK.

Load it with bulbs from car headlights.

After the conversion (see post 5), I use the power supply with the charger Lipo Imax B6 and a polystyrene cutter, and the power supply itself works without any problems.

I close the topic, thank you for all the answers.