AC Ripple and Power Factor
AC Ripple and Noise on the DC Outputs
The amount of AC ripple and noise present on the DC outputs was checked using an oscilloscope. This AC component may be present in the KHz range where most switching power supplies operate or it may be more prevalent at the 60 Hz line frequency. I adjusted the O-scope time base to look for AC ripple at both low and high frequencies.
The new ATX12V V2.2 specification for DC output noise/ripple is defined in the ATX12V Power Supply Design Guide.
Ideally we would like to see no AC ripple (repetitive) or noise (random) on the DC outputs – the cleaner the better! But in reality there will always be some present. I measured the amplitude of the AC signal (in millivolts, peak-to-peak) to see how well the power supply complied with the ATX standard. The following table lists the ripple/noise results during all of the load tests for the main output voltages of interest.
Overall, the two Corsair TX Modular power supplies exhibited very good AC ripple suppression across the entire load range, even when delivering their maximum rated capacities. In years past, this was frequently a weakness of some CWT platforms but they have done a great job of keeping the AC ripple well under control on these units.
Power Factor (PF)
Power factor is defined as the ratio of true power (measured in watts) to apparent power (measured in Volt Amps). It measures how effectively AC power is being used by a device. The difference between true power and apparent power is expressed as the power factor and results from the way true power and apparent power are measured. Ideally we would like to have true power and apparent power equal to one another, which would result in a PF of 1.00 or 100% effective power utilization.
AC Volts x AC Amps = VA (Volt Amp)
Purely Resistive AC Load: VA = Watts (same as DC circuits)
Inductive/Reactive AC Load: VA x PF = Watts
AC Volts x AC Amps x PF = Watts
I measured the AC Power Factor with an Extech power analyzer at both 115 VAC and 240 VAC input voltages. The two TX Modular power supplies use Active PFC circuits so as expected; the majority of readings were at or close to 1.0 at the higher loads.
Note: A power supply with active PFC is more environmentally friendly (doesn’t pollute the AC transmission grid with harmonics) and will draw less current, but it will not save you money on your monthly electric bill unless you are a commercial user whose bill is based on PF and usage.
The only complaint is these
The only complaint is these things NOT fully modular.
and these things are
and these things are basically noise free under normal load, the fans RARELY kick on/
and their made by
and their made by Seasonic….ok I’m done I swear
SEASONIC IS A BAD COMPANY? AS
SEASONIC IS A BAD COMPANY? AS LONG AS IT GETS THE JOB DONE. I’M ONE OF THOSE LIGHT GAMERS I GUESS.
Corsair is THE best power
Corsair is THE best power supply manufacturer by far. I believe this particular model has a MTBF (mean time between failure) of 100,000 hours, which is insane. I am running a GTX 295, overclocked core i7, DVD burner, 10k hard drive, and 6 gigs of 1600 Mhz Ram with ease on this power supply with breathing room. When I get my other GTX 295 and hook up the Quad SLI, add another hard drive, blu-ray burner, and 6 more gigs of ram, I will need a 1200W power supply and I really wish Corsair made one. The only real “con” is that it isn’t modular so you need to have decent cable management to keep the airflow tip top. Buy this, you won’t be disappointed.