Power Supply Components - Keithley 2015 Service Manual

AC power is applied to the AC power module receptacle (J1009). Power is routed through the
line fuse and line voltage selection switch of the power module to the power transformer. The
power transformer has a total of four 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.
Table 4-1 summarizes rectifier, filter, and regulator circuits for the various DC supplies.
Table 4-1

Power supply components

Supply Rectifier
+5VD CR104
+37V CR116, CR117
+15V CR102
-15V CR102
+5V, +5VRL CR103
+5VD2 CR301
+15VF CR330
-15VF CR330
+5VF CR331
Troubleshooting
Filter Regulator
C128, C156 U144
C104, C106 U101
C148 U125
C131 U119
C146 U124
C350 U331
C562 U348
C565 U349
C568 U350
4-7