Monopolar Control/Display
5-2
Force 2 Service Manual
When functioning as the main control element of the generator, the
Monopolar Control/Display board produces the proper RF drive
according to the mode selected. It calculates and generates the required
power supply control voltage. It also calculates and sets the current limit
for the RF output stage.
The main control element on the CPU board is an 89C54, a single chip
microcontroller with 16k of on-board electronically programmable read-
only memory (EPROM). The firmware residing within the 89C54
implements the performance requirements of the Monopolar Control/
Display board. This section provides a description of the Monopolar
Control/Display board hardware.
An Intersil ICM7218C display multiplexer (U8) performs the major
display functions of the Monopolar Control/Display board. The device is
a universal, eight digit, LED driver system. It contains all the circuitry
necessary to interface a microcontroller to a multiple seven segment LED
display:
• An 8 x 8 static memory array with storage for the displayed
information
• Seven segment decoders
• All multiplex scan circuitry
• The high power digit and segment drivers.
Mode Indicators
The ICM7218C is not capable of driving the mode indicators with enough
power to make them fully visible through the translucent display
windows. The microcontroller writes a bit pattern on the ICM7218C digit
drive bus; the pattern corresponds to the mode displays to be illuminated.
Segment H, the decimal point drive output of the ICM7218C, gates each of
the eight digit drive lines through U28 and U29 to provide external
multiplexing for the mode indicator information. A ULN2803A, U27,
boosts the resultant mode indicator drive current.
Summary of Contents for Force 2-2 PCH
Page 1: ...Service Manual Force 2 Electrosurgical Generator...
Page 10: ...Notes x Force 2 Service Manual...
Page 16: ...Notes 2 4 Force 2 Service Manual...
Page 32: ...Notes 4 10 Force 2 Service Manual...
Page 52: ...Typical Output Waveforms 6 12 Force 2 Service Manual Figure 6 5 Coag 300 Load...