|
The widespread activity in the field of computers has made the common man more
and more computer oriented in every field of life. Computers have made his work
much more efficient and refined than his predecessors. Most of the things where
help of professionals was necessary, are now done or at least pre-formatted by the
common man. However computers depend almost totally on clean power. There
are various power conditioning equipments available in the market, but the choice is
made difficult by various claims made by the suppliers. A swift trip in the field might
be fruitful. Various products are available :
1.Servo Controlled Voltage Stabilizer :
This is a stabilizer. which constantly monitors the output voltage and controls the
variations in the input voltage
by movements of a motor. This motor in turn selects the proper output voltage on the variable transformer
(variac). This is probably the cheapest power-conditioning product available. It gives reasonably good voltage
regulation and is all right where voltage fluctuations are not considerable. However it
is not advisable to use it outside big cities where apart from considerable fluctuations
in voltage, the power is full of frequency drifts, failures, noise and spikes.
2.Ultra Isolation Transformer:
This is a product, which totally isolates the sensitive equipment from Mains power.
Not only the spikes but
also the noise in the R.F region on the common line i.e neutral is isolated. Coupled with a servo stabilizer,
it provides an answer to most of the power problems. However besides being costly, it cannot compensate
frequency drifts and sudden temporary blackouts even when coupled with stabilizer.
3. Constant Voltage Transformer :
As the name suggests, this is basically a voltage-regulating device.
However, apart from maintaining the voltage, it also provides a reasonable degree of isolation and
rides over blackouts of a few milliseconds. Apart from frequency drifts and power
failures, this provides answer to almost all power problems.
4.0ff-line UPS:
In this system, the load is normally on Mains power supply. This may be regulated
to some extent by an in-built voltage regulator. When the Mains power
fails, the inverter takes over and supplies power to the load while draining the battery. This is
a cheap system for countering the power failure problem. However, it is not advisable
to use this at places where voltage fluctuation is severe and in areas where large
power consuming machinery is being used. This machinery, while being switched
ON & OFF, causes high energy spikes which can damage sensitive equipment
permanently.
5.
On-line UPS:
This perhaps is the only complete answer to power line problems. In this
system, the load is always connected to the inverter. This inverter works either on rectified Mains
voltage in case of the Mains power being available, or works on battery in case of
Mains failure. The rectified Mains and battery being connected in
parallel. This system is a true No-Break power supply. Load being always on inverter, it is totally isolated
from all the power problems like fluctuations, brownouts, spikes, frequency drifts,
noise etc. Thus this system is the most advisable in the areas where clean power is
important.
In the light of above, need of the sensitive equipment, problems related to the area,
future planning like expansions and naturally the budget will decide upon the power
conditioning equipment to be chosen. This is precisely the field where a saving
today might prove expensive tomorrow.
6. Inverter An
inverter is used to provide power to min. critical load in case of Mains
power failure. Most of the Inverters available in market are general
purpose, meant only for lighting load, They can not handle any power
surge & are prone to failure under such conditions. This is
where a heavy - duty inverter comes into picture. A heavy duty inverter
can handle tremendous momentary loads as close to short circuit as
possible & even short circuit without getting damaged. The
output is sinusoidal & can be fed to sensitive instruments.
The no load to full load regulation is much better compare to that of
general inverter & from inverter to mains is achieved by electro
mechanical relay. In
the light of above, need of the sensitive equipment, problems related to
the area, future planning like expansions and naturally the budget will
decide upon the power conditioning equipment to be chosen. This is
precisely the field where a saving today might prove expensive tomorrow. |
