Rosewill Capstone 750W Power Supply Review

Test Setup

In order to be able to effectively
and efficiently test any computer power supply unit, we developed and
constructed our own proprietary testing station. Our testing station consists
of a number of power resistors and small capacitors, which in turn are
connected to a RS485 electronic relay array which allow our load to be
controlled through computer software alone.

When accuracy and speed are of
critical importance, a simple multimeter or voltage meter is not sufficient for
the task. To ensure the quality of our testing, an USB laboratory interface is
being used to continuously monitor and record the readings of all voltage lines
simultaneously. For ripple measurements, an oscilloscope is necessary and we
chose the USB Instruments Stingray, the most widely used oscilloscope amongst
low voltage PSU engineers and testers.

For accurate testing and repeatable
results, a stable power input is also required. Thus, we are providing power to
our test samples through a 3kVA VARIAC which allows us to control the input
voltage of our test samples and also perform efficiency tests under both 110V
AC and 230V AC input. A Lutron DW-6091 is also being used, monitoring the input
voltage, real and apparent power, power factor and amperage.

A power supply testing procedure
would not be complete without thermal and acoustics tests. For our acoustics
tests we are using a SL-5868P digital sound level meter, placed 1 meter away
from the unit (DIN standard). Two PT100 sensors and their respective displays
are being used to monitor the ambient temperature and the exhaust temperature
of the unit.