Samlexpower SI-750HP Owner's Manual - page 5
3. HOW YOUR SAMLEX INVERTER WORKS
The inverter converts low voltage DC (direct current) from a battery or
other power source to standard 110 volt AC (alternating current)
household power.
3.1 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 110 volts, 60 Hz AC.
The DC-to-DC converter stage uses modern high frequency power con-
version 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 ex-
cellent overload capability and the ability to operate reactive loads like
lamp ballasts and small induction motors.
FIGURE 2
Principle of Operation
FIGURE 1
1. RED SHUT DOWN LED
2. GREEN OPERATING LED
3. (3 ) 115 VAC RECEPTACLES
4. ON/OFF SWITCH
5. HIGH SPEED COOLING FAN (not shown - on back of unit)
6. (+) DC POWER CONNECTION (not shown - on back of unit)
7. (-) DC POWER CONNECTION (not shown - on back of unit)
12 VDC to
145 VDC
Conversion
145 VDC to
110 VAC
Conversion
Internal
Fuses
Three AC
Outlets
110 VAC, 60hZ
To AC Appliances
5.
1.
2.
4.
3.
7. COMMON PROBLEMS
“Buzzing” sound in audio systems:
Some inexpensive stereo systems and “boom boxes” emit a buzzing sound
from their speakers when operated from the SI-750HP power inverter. This
occurs because the power supply in the electronic device does not adequately
filter the modified sine wave produced by the inverter. The only solution to
this problem is to use a higher quality sound system that incorporates a
higher quality power amplifier supply.
Television Interference:
The SI-750HP is shielded to minimize interference with TV signals.
However, in some instances, some interference may still be visible,
particularly with weak TV signals. Try the following corrective measures:
• Position the inverter as far as possible from the television, the antenna
and the antenna cables. Use an extension cable, if necessary
•
Adjust the orientation of the inverter, the antenna cables and the TV
power cord to minimize interference
Make sure that the antenna feeding the television provides an adequate
(“snow free”) signal and that high quality, shielded antenna cable is used
8. TROUBLESHOOTING GUIDE:
TABLE 1 - INVERTER POWER SWITCH TURNED ON
TROUBLE/ INDICATION POSSIBLE CAUSE
SUGGESTED REMEDY
No AC output-
DC input below 10 Volts Recharge or Replace
red LED lit
battery
No AC output-
Excessive appliance
Reduce load-wait for
red LED lit
load-thermal shutdown
inverter to cool. Turn
Off, then turn On
No AC output
Inverter cold
Disconnect load from
inverter. Operate
inverter without load for
a few minutes.
reconnect load.
No AC output- Inverter input fuse open
Check fuse and wiring.
Green LED not lit
Repair and replace fuse.
12.
12 VDC
Input