Display Board - Keithley 2182 Service Manual

AC power is applied to the AC power module receptacle. Power is routed through the line
fuse and line voltage selection switch of the power module to the power transformer. The power
transformer has several secondary windings for the various supplies.
AC voltage for the display filaments is taken from a power transformer secondary at F1 and
F2, and then routed to the display board.
Each DC supply uses a rectifier and a capacitive filter, and many supplies use an IC regulator
or transistors. The various components are shown

Display board

Display board components are shown in the digital circuitry block diagram in
Figure 4-2
Digital circuitry block diagram
XADTX
XADCLK
Analog
XADTS
Circuitry
(See Figure 4-3)
XADRX
NVRAM
U102, U103
U112
O
P
ADTX
T
O
ADCLK
ADTS
I
S
O
ADRXB
U114,
U115,
U116
TRIG IN
Trigger
TRIG OUT
U113
Trigger
Link
inFigure 4-1.
ROM RAM
U104, U105
68306
Display Board
µP
Controller
U401
U101
XTAL
Y101
IN
RS-232
U110
OUT
Data IN
U106, U108,
Data OUT
Troubleshooting
Figure
Keypad
Display
DS401
RS232
Port
GPIB
IEEE-488
Bus
U109
4-5
4-2.