Vector VEC550POB Owner's Manual & Warranty - page 5
THEORY OF OPERATION
The inverter changes 12 VDC into 120 VAC (120 VAC RMS), electrical power. This
is accomplished in two stages. The first stage raises the 12 VDC input to 145 VDC
through modern high-frequency conversion techniques. The output stage changes
the 145-VDC to 120 VAC. The inverter's output stage uses multiple banks of metal-
oxide semiconductor field-effect transistors (MOSFETs) to alternately apply
opposite polarity to the AC outlet's HOT and NEUTRAL terminals. The AC output
approximates a sine wave in shape. This is called Modified Sine Wave (MSW) and
it has the same energy characteristics as the sine wave of commercial electrical
power.
FIGURE 3 - SINE WAVE AND MSW COMPARISON
NOTE: A TRUE RMS voltmeter must be used for measuring MSW. If the output of
the inverter is measured using standard digital or analog voltmeters, these
instruments may not correctly read the voltage. They typically will read from 10 to
20 volts low.
AC APPLIANCE CAUTIONS:
DO NOT plug small appliances into the inverter receptacles to directly recharge their
nickel-cadmium batteries. Always use the recharger provided with that appliance.
Do NOT plug in battery chargers for cordless power tools if the charger carries a
warning that dangerous voltages are present at the battery terminals.
Not all fluorescent lamps operate properly with this type of inverter. If the bulb
appears to be too bright, or fails to light, do not use the lamp with this inverter.
Fans with synchronous motors may slightly increase in speed (RPM) when
powered by the inverter. This is not harmful to the fan or to the inverter.
Certain chargers for small nickel-cadmium batteries can be damaged if plugged into
the inverters. In particular, two types of appliances are susceptible to damage:
•
Small, battery-operated appliances such as flashlights, cordless razors
and tooth brushes that can be plugged directly into an AC receptacle
to recharge
• Certain battery chargers for battery packs that are used in some cordless
hand-tools. Chargers for these tools have a warning label stating that
dangerous voltages are present at the battery terminals
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110/120V AC
110/120V AC