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24
In the
REMOTE
position, the PIC locks-out the front-panel buttons and
instead responds to RS-232 serial commands for setting processing
parameters. IC7 is an RS-232 level translator, buffering the serial data
send and receive lines from the PIC.
POWER SUPPLY (Schematic Sheet 2, Page 30)
Model 235 circuitry utilizes ±9-volt supplies for op-amps and other
linear circuitry, and a +5-volt supply for digital logic. These three
sources are each regulated by a “3-terminal” linear voltage regulator;
IC4 for +9 volts, IC6 for –9 volts, and IC5 for +5 volts.
The power transformer, T1, has dual primary windings which may be
switched in parallel or in series to accommodate 115V or 230V mains,
respectively.
Summary of Contents for 235
Page 31: ... 29 Schematic Sheet 1 29 ...
Page 32: ... 30 Schematic Sheet 2 30 ...
Page 33: ... 31 Schematic Sheet 3 31 ...
