Power
Supply testing methodology
In
order to efficiently test a power supply unit,
one must first be able to deliver specific load
quantities. Simply connecting it to any kind of
PC system will not work, since the load does not
only vary depending on the system state but the
precise power consumption is also unknown. Automatic
monitoring of the lines from a quick reading voltage
meter is also necessary to eliminate both human
errors and the voltage meter reading lag. Here
at Driver Heaven we strive to provide you with
useful and thorough reviews and for that we have
built a custom power supply testing station which
allows us to efficiently analyse any consumer
and industrial AC to DC power supply unit available.
With
the help of proper equipment and tools, our testing
station became compact enough to fit inside a
small carrying case. The basic design is simple.
By using proper aluminum enclosed wire wound resistors
we can load any voltage line with the exact amount
of power of our choice, down to 1A steps and up
to 1.6KW maximum power consumption. But our planning
is not limited to that. By using bullet type connectors
on all lines we can change the connections to
suit our needs and counter different voltage line
designs, ensuring that different power supply
units can be tested properly. Furthermore high
quality cables and soldering joints minimize power
loss, while four analog ampere meters allow us
to continuously watch the power load of four lines.
Finally, four 92mm and two 80mm high speed fans
ensure that our resistors stay cool enough to
perform, as the properties of all wire wound resistors
immensely degrade once they heat up.
For testing the efficiency
of a power supply unit an AC power meter is necessary.
The AC power meter allows us to monitor how much
power the unit is drawing from the AC line, allowing
us to calculate the efficiency within a 1% tolerance.
Finally a Mastech 8218 high accuracy multimeter
with RS232 interface allows us to monitor the
voltage lines between 0.5s intervals via PC software.
The Mastech 8218 is fast enough to catch any voltage
fluctuations, it is as accurate as ±0.08%
VDC and the PC connection via RS232 interface
will eliminate any human errors while it also
allows us to take a monitoring graph.
In
order to thoroughly analyse each power supply
we will test variations of power loads, ranging
from 30% of its rated capacity to its maximum
capability. We will take voltage readings at set
loads to monitor the power delivery capabilities
of every line but we will also take voltage readings
from all lines while aggressively switching between
30% and 100% load in order to test the capabilities
of the voltage regulation unit and hence the voltage
stability in real world applications. Finally,
we will also take efficiency readings from 30%
to 100% load in 10% steps.