Valleylab Force FX-8C, Руководство по обслуживанию

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Display Board
Principles of Operation
Force FX-8C Service Manual 4-13
Display Board
Refer to Section 9 for components and the Schematics Supplement for
Board Drawings and Schematics.
The Display board is located in the front panel assembly. It contains RF
indicator lamps, seven-segment LED power setting displays, REM alarm
LEDs, and a CEM indicator LED. The display board switch circuitry
includes the LED and lamp driver circuitry, power selection switches,
mode selection switches, the REM switch circuit, and the CEM switch
circuit.
RF Indicator Lamps
The RF indicator lamps illuminate during RF activation to visually
indicate the presence of RF power. Each of the three indicator bars
(Bipolar, Cut, and Coag) on the front panel is illuminated by four
incandescent bulbs (LP1–LP12).
• LP1–LP4 illuminate the blue Bipolar bar, indicating bipolar activation.
• LP5–LP8 illuminate the yellow Cut bar, indicating cut activation.
• LP9–LP12 illuminate the blue Coag bar, indicating coag activation.
The RF indicator lamps are controlled by the BIP_LMP, CUT_LMP, and
COAG_LMP signals. These signals originate from port A of the main
microcontroller programmable peripheral (U3) on the Control board.
Buffers in U1 turn the RF indicator lamps on and off. Resistors R1–R12 set
the amount of current flowing through the lamps when they are turned
on. The value of these resistors varies for each indicator bar, depending on
the color of the bar, to make the different colors of the bars illuminate with
equal intensities.
REM Indicators
The REM indicator consists of two bicolor LED arrays incorporating one
red and four green LEDs per array. The LEDs are controlled by the
REM_RED and REM_GREEN signals originating from port A of the main
microcontroller programmable peripheral (U3) on the Control board. The
signals are buffered on the Display board by driver U1. Both the red and
green LEDs are current limited by 100 ohm resistors (R13, R14, R15, and
R16).
LED and Seven-Segment Display Drivers
This circuit contains three display drivers for the LEDs and the seven-
segment displays. The LEDs indicate modes of operation, and the REM
condition. The seven-segment displays indicate bipolar, cut, and coag
power settings.