Covidien Force FX, Service Manual

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Power Supply/RF Board
Principles of Operation
Force FX Electrosurgical Generator C Service Manual
4-19
Power Supply/RF Board Interfaces
The Power Supply/RF board interfaces to other boards and components as follows:
• AC input line filter
• Control board
• Footswitch board
• Heat sink components (RF damping resistor, RF MOSFET, and high voltage power
supply MOSFETs)
• Single-wire attachment points for connecting the sense transformers
• Low voltage power supply (AC input and DC output)
• Low noise fan
A series of fuse clips connect the RF outputs and other front panel interfaces (i.e., REM
and handswitching signals). The fuse clips mate to lugs located in the output portion of
the front panel.
High Voltage Power Supply
The high voltage power supply section contains the power entry circuitry, auto mains
switching circuitry, AC/DC conversion circuitry, and a DC/DC switching regulator.
Power Entry Circuit
The power entry circuit consists of an integral three wire power cord receptacle, fuse
drawer, EMI filter, and a separate power switch. The power switch is mounted on the
front panel. The receptacle/filter is mounted on the rear panel of the generator. AC line
fuses are changeable from the rear of the generator.
Auto Mains Switching Circuitry
The auto mains switching circuit detects the AC line voltage level and controls the triac
(D1). This triac controls the topology of the AC/DC converter.
For 120 Vac operation, the triac is on, which connects the AC neutral to the center of the
AC/DC converter capacitor bank (C3, C10, C11, and C22). In this configuration, the
circuit acts as a doubler using the right hand half of the bridge rectifier (CR80).
Warning
Potentially lethal AC and DC voltages are present in the AC line circuitry, high voltage DC circuitry,
and associated mounting and heat sink hardware described in this manual. They are not isolated
from the AC line. Take appropriate precautions when testing and troubleshooting this area of the
generator.