-12V & +12V Power Supply fluctuations

[gustavo]

Hi, Would you know what would be normal allowable limits for the +12V & -12V Power Supply ??
My PCAlert has a limit at +13.2V & -13.2V and sometimes the -13.3 is reached and I don´t know if it is allowable.

Thanks Gustavo.-
😕

 

[CTho9305]

i think this is the wrong forum. I know that down to 11 is fine... but i dont know about the upper end (usually PSU's undervolt)

 

[Mark R]

The recommended limits are +/- 5% for 12 V (i.e. 11.4 - 12.6 V) and +/-10% for -12 V (i.e. 10.8 - 13.2 V). Although +/-10% is acceptable for +12 V.

You should also bear in mind that the voltage monitors built into PCs can be inaccurate by 5-10%, and therefore a reading of -13.3 V could actually correspond to a voltage well within limits.

 

[Jerboy]

<< Hi, Would you know what would be normal allowable limits for the +12V & -12V Power Supply ??
My PCAlert has a limit at +13.2V & -13.2V and sometimes the -13.3 is reached and I don´t know if it is allowable.

Thanks Gustavo.-
😕 >>



Onboard diagnostic is not accurate and is certainly not calibrated. Use a DC voltmeter of .5% accuracy or better and measure it directly from motherboard ATX connector. Push the probe into back of the connector. Black is ground, and keep on probing (other than black) until you get -12V. You only have to probe same colored wire once as they carry the same voltage.