3
HOW THIS INVERTER WORKS
SPECIFICATIONS
The inverter converts low voltage DC (direct current) from a battery or other
power source to standard 120 volt AC (alternating current) household power.
Principle of Operation
The inverter converts power in two stages. The first stage is a DC-to-DC
conversion process that raises the low voltage DC at the inverter input to 145
volts DC. The second stage is the actual inverter stage that converts the high
voltage DC into 115 volts, 60 Hz AC.
The DC-to-DC converter stage uses modern high frequency power conversion
techniques that have replaced the bulky transformers found in less
technologically-advanced models. The inverter stage uses advanced power
MOSFET transistors in a full bridge configuration. This ensures excellent overload
capability and the ability to operate reactive loads like small induction motors.
The Power Inverter Output Waveform
The AC output waveform of the Power Inverter is known as “modified sine wave.”
It is a waveform that has characteristics similar to the sine wave shape of utility
12VDC to
145VDC
CONVERSION
145VDC to
115VAC
CONVERSION
Internal
Fuses
AC
Outlet(s)
12VDC
Input
115VAC, 60Hz
to AC appliances
2
• Output Waveform: Modified Sine Wave
• Input Voltage Range: 10 to 15 VDC
• Low Voltage Alarm: approx. 10.5 VDC
• Low Voltage Shutdown: approx. 9.5 VDC
• Additional Protection: Overload, Over voltage, Over temp.
power. This type of waveform is suitable for most AC loads, including linear and
switching power supplies used in electronic equipment, transformers, and motors.
The modified sine wave produced by the Power Inverter has an RMS (root mean
square) voltage of 115 volts, which is the same as standard household power.
Most AC voltmeters (both digital and analog) are sensitive to the average value of
the waveform rather than the RMS value. They are calibrated for RMS voltage
under the assumption that the waveform measured will be a pure sine wave.
These meters will not read the RMS voltage of a modified sine wave correctly.
They will read about 20 to 30 volts low when measuring the output of the inverter.
For accurate measurement of the output voltage of this unit, use a true RMS
reading voltmeter such as a Fluke 87, Fluke 8060A, Fluke 77/99 series, Beckman
4410, or Triplett 4200.
Modified Sine Wave and Sine Wave Comparison
OPERATING INSTRUCTIONS
Power Source Requirements
The power source must provide 12.8 volts DC and must be able to supply the
necessary current to operate the load. The power source may be a battery or a
well-regulated DC power supply. To obtain a rough estimate of the current (in
amperes) the power source must deliver, simply divide the power consumption of
the load (in watts AC) by 10.
Example: If a load is rated at 200 watts AC, the power source must be able to
deliver: 200 divided by 10 = 20 amperes
The Power Inverter must be connected only to batteries with a nominal
output voltage of 12 volts. The unit will not operate from a 6 volt battery and
will sustain permanent damage if connected to a 24 volt battery.
Connection to Power Source
The Power Inverter comes equipped with a DC accessory outlet plug and battery
clip cables for connection to a power source (Models 1045BD and 1046 BD only).
Connecting to a Power Source Using the Accessory Outlet Plug
The DC accessory outlet plug is suitable for operating the inverter at power outputs
up to 100 watts. The tip of the plug is POSITIVE (+) and the side contact is
NEGATIVE (–).
Connect the inverter to the power source by inserting the DC accessory outlet
plug firmly into the accessory outlet of a vehicle or other DC power source.
• Connect directly to power source when operating above 100 watts.
CAUTION
CAUTIONS
• Do not use with positive ground electrical systems.
• Reverse polarity connection will result in a blown fuse and may cause
permanent damage to the inverter.
Notes: Most vehicle accessory outlet circuits have fuses rated at 15 to 20 amps or
greater. To operate at full wattage, either use the battery clip cable
(supplied) or directly wire to the power source with user-supplied wire and
fuse. The majority of modern automobiles, RVs and trucks are negative
ground.
