Variable DC power supply
A computer variable DC power supply is often an afterthought
for people buying computer components. In past years, most personal
computer cases on the market came with a factory installed variable DC power supply but over time this has changed. In fact, many of
the cases that do still have power supplies in them tend to have
inferior or low quality units installed in order to reduce costs
for the manufacturers. Most high end computer cases will actually
no even come supplied with a variable DC power supply so that users can
get a unit that bests matches their components.
Variable DC power supply Basics
While a computer gets plugged into a wall outlet
that typically has 115 volts of electricity coming from it, the
power needed by the computer components needs a lower voltage.
Electricity running at such high voltage levels would burn out
the transistors within the computer chips rendering everything
in the computer useless. This function of converting the higher
voltage power from the utilities to the lower voltages required
by the computer components is the primary function of the power
supply unit.
There are typically three voltage levels that
the power supply unit needs to step down the high voltage to:
3.3v, 5v and 12v. The power supply delivers the lower voltage
electricity to the various components through the myriad of power
connectors that run out of the power supply. Most of these connectors
are either the 4 pin Molex connectors that are plugged into the
hard and optical drives inside of the computer. A smaller 4 pin
floppy connector also exists but is increasingly being used for
other devices instead of floppies. Finally there is the power
block which connectors into the motherboard.
Variable DC Power Supply Wattage: Is More
Better?
All variable DC power supplies are generally sold
based on their wattage rating. What people don't know is that
this is the combined total wattage rating of the power supply
at full load across each of the individual voltage lines. Since
the variable DC power supply has multiple voltage outputs, each
voltage rail will pull its own current from the power supply.
Thus, two different power supplies both rated at 450 watts may
have completely different power characteristics when it comes
to the amount of power delivered to each of the voltage lines.
|
