Help me find out my Power Supply Unit Wattage!!

joeman99_16

Honorable
Jan 2, 2013
2
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10,510
Hello, i wanted to know my psu wattage so i opened my cpu case and looked at my psu and saw a sticker which had the following information :
"Prime Source Technologies ATX switching power supply

Model : HK-300FA

AC input 220/110 VAC
50/60 Hz 2/4A

Fuse Pating : F5A
250 VAC

DC Output MAX. +3.3V - 14A
+5V - 20A
+12V - 10A
-5V - 0.5A "
 

In a modern PC the +12 V rail is the most important. So based on the posted figures, you have a MAX of 120 Watts on the 12-volt rail.
You have a MAX of 46.2 watts on the +3.3 volt rail
You have a MAX of 100 watts on the +5 volt rail.

Now, the PSU will NOT supply the max wattage of each rail at the SAME time, so I am guessing that your PSU is rated somewhere between 150 -200 watts, with a 250 watt absolute max.
 
That power supply design is quite old since the -5V rail was removed from the ATX12V specifications back in 2002.

The 300 in the model number most likely refers to 300 Watts peak.

I would agree with clarkjd that your specific model would definitely be rated at 250 Watts or less.