Inverters come in all shapes
and sizes and equally in price range as well. You can expect
to pay anything from £50 - £2,000 depending on what
your requirement from your inverter is. Generally you get what
you pay for with inverters, so work out your loads and add a
bit for any future requirement.
The INVERTER is the electronic
device that converts the 12, 24, or 48 volt DC current from
the battery into AC current (240 volts), the same as the power
for standard household lights, sockets outlets, and appliances.
There are basically two types of inverters: modified
and sine wave
The differences are quite small but significant when they power
certain types of equipment .
Modified sine wave
Modified inverters can adequately power most household appliances
(about 95%) and power tools. They are more economical with the
power, but for some certain loads such as microwave ovens, laser
printers, clocks and cordless tool chargers you may experience
Pure Sine wave
Pure sine wave inverters supply power of better quality than
the modified inverter, and work correctly with more or less
Solving the inverter issues:
It may be an advantage financially to mix your requirement by
having a modified sine wave inverter for most of your requirement,
and smaller special pure sine wave inverter for when you have
appliances that require pure true sine wave power.
Inverters are rated by their continuous wattage output and can
briefly sustain higher loads than they can run continuously,
because some loads mainly with motors, require a power surge
to start. You therefore have to allow for this surge in your
estimation of your power requirement. Good manufacturers state
the continuous load and the surge load capacity as the inverter
in the right hand picture above does i.e. 600 watts continuous
and a 1500 watt surge. Most manufacturers give quite clear information
these days in the hand books or operating instructions, its
just a matter of getting used to looking for them.
Lets look at an example, say you want to run a 15-inch TV, a
VCR, and two lights at once. Total up all the wattage's, about
32 watts for the TV, 25 watts for the VCR, and 14W for the two
lights, this is a total of 71 Watts. Now pick an inverter that
can supply at least 71 watts continuously, and you are ready
to go. Obviously if you want to use appliances with a surge
load then you must make allowances for that.
Powering a whole house full of appliances and lights will take
more planning and working out. Not every appliance and light
will all be on at the same time. Mid - sized inverters of 600
to 1,500 watts do a good job of running lights, stereo equipment,
small kitchen appliances and chargers for all those gadgets.
These mid - sized inverters will not run a middle ranged microwave,
a washing machine, or some larger handheld power tools. For
these substantial loads you need an inverter rated at about
2000 watts. Experience shows that once you start thinking about
an inverter of this size you tend to end up with a full-size
inverter because household requirements always grow, and the
larger inverters are the better solution in the end.
All inverters produce heat albeit small amounts and the more
you have plugged in and working the hotter it will get before
finally cutting out or limiting their output. With global warming
an issue learn to choose appliances that are designed to have
power saving features and it will help to keep your load down.
Some hi-fi and stereo equipment can pick up a 60-cycle buzz
heard through the speakers. It won't hurt the equipment, but
it's very annoying and not what you want to put up with. There
are far too many models to say specifically which are a problem
and which aren't. More recently manufacturers are starting to
put better power supplies into their products, this has been
a personal bug of mine as quite blatantly manufacturers of set
top boxes etc have under specified their equipment in an effort
to produce smaller and cheaper models. I have given up counting
how many power supplies I have replaced over the years due to
overheating because they are under specified.
Some expensive power audio products are protected by SCRs or
Triacs. This circuitry is installed to protect against power
line spikes and surges. Some however, see modified sine wave
as no good and will prevent the unpure power from reaching the
delicate inner circuitry and will not power up. The only sure
cure for this is a pure sine wave inverter. Your biggest concern
I am sure will be your computer and I can assure you that 99%
of computers run well on modified sine wave power inverters.
Laser printers are not a good choice because they have a high
standby power use while the good old inkjet printers will do
the same job more or less while only using about 30 watts instead
of 900 plus watts.
A word about Phantom loads: lots of modern appliances remain
partially on when they appear to be turned off, although the
pressure is now on for manufacturers to change this method of
standby. If you have appliances that are powered up by remote
controls (zappers) these have to remain partially on and waiting
to receive an 'on' signal. All appliances with digital clocks,
microwave ovens, coffee makers, set top boxes and bedside clocks
use small amounts of power all the time that can collectively
demand quite a bit of power. Everything that uses a transformer
plugged into the wall 240 volt AC socket uses tiny amounts of
power, apart from the power wasted they can make some automatic
inverters stay turned on and running constantly.
Warming - it's why we are making changes to our way of life!
David Bellamy has a very interesting article on global warming
where he gives another point of view, Read