PSU Inside

Please take a look at the inside and notice the empty space between heatsink and fan. This has been specifically added to reduce air turbulence inside the case. According to PCP&C this can have an effect of up to 10 dB in fan noise.

Test Equipment

• The PSU is connected to an APC SmartUPS which supplies clean 220V input.
• AC current is measured using a Peaktech 4010 desktop RS232 multimeter with 0.02A accuracy.
• To measure DC output voltages of the PSU we use a Keithley 2700 6.5 digit data acquisition system. All three input voltages are measured at the same time using a solid state switching system.
• Power Factor is measured using a generic Power Efficiency Meter.
• Measurements for Ripple Voltage were obtained using a 100 MHz Tektronix TDS224 Digital Storage Oscilloscope.

Fan noise measurements are performed with an IEC Type 2 Sound level meter and this setup.
It consists of three high-power resistors and a Socket A motherboard. The motherboard creates a small load which makes sure the PSU turns on (some PSUs require a minimum load). Since there is no hardware installed in the motherboard, its power draw is negligible. The three resistors create a static load of 320W (120W @ 12V + 50W @ 5V + 150W @ 12V) - a typical high-performance system. This setup is also used to determine the power conversion efficiency of the PSU.