Control Board
4-6 Force FX-8C Service Manual
• Audio control
• Memory control and storage (system alarms with time stamps;
calibration values)
• Real-time clock control and interface
• Internal self-tests
• Communicating with the feedback microcontroller.
Main Microcontroller Memory
A PSD413 programmable peripheral (U3) provides program memory
(128K x 8 external EPROM) and data memory (2K x 8 external battery-
backed static RAM) for the main microcontroller. Additional data memory
is available from these sources:
• 256K x 8 microcontroller internal RAM
• 4K x 8 external static RAM (U4) shared with the feedback
microcontroller.
Battery-Backed RAM
A socket on the Control board contains a 3.0 V lithium button cell battery
(BT1) that provides backup power for the 2K x 8 external RAM on the
PSD413 device (U3) used by the main microcontroller. The battery-backed
RAM stores calibration constants, last setup parameters, and temporary
data.
Feedback Microcontroller
The feedback microcontroller (U11), like the main microcontroller, is an
80C562. It receives commands from the main microcontroller and, when
the generator is activated, establishes the appropriate relay closures and
activates RF output. It continually adjusts the output signal of the
generator by controlling the high voltage DC power supply and the RF
clock circuitry. It is primarily responsible for these functions:
• Scaling relay control and output relay control
• T_ON ASIC waveform control
• Leakage control (coag)
• Constant voltage, current, and power feedback control
• ECON initialization
• Real-time information update (actual voltage, current, power,
impedance, effect mode)
• Memory tests
• Communicating with the main microcontroller.
To Next Page
Loading...
