Model 240A Section IV
Paragraphs 4-65 to 4-67
OA3 tube, V606; (b) the full-wave selenium rectifier ha on it a source of unregulated filaments at 6.3
circuit consisting of CR602A, B, C and D and the volts, the high voltage winding used to feed the plates
associated filter by way of transformer r603; and of the high voltage rectifier, V605, and the filaments
(c) the dual-winding filament transformer, T604, of V605.
whose output is used to feed critical filaments througk
out the system. The main power transformer, T601, 4-66. The filaments of the high-voltage rectifier,
V605, are fed through a thermal delay Type 6N030,
S602, whose filaments are driven from the unregu-
lated 6.3~ Supply. This switch, S602 introduces ap-
proximately a 30-second delay between the time of
application of voltage to the filaments and closing of
REG.250V DC the contacts to the rectifier, V605, thus delaying the
V604. V003 6.3V DC application of the high voltage to all tubes in the cir-
6.3V AC LCC 602
cuit. The output of the rectifier, V605, is fed through
series regulator tubes V604 and V607 which are con-
trolled in turn by the reference tube and dc amplifiers
6.3V AC V602 and V603. The output voltage is controlled by
the reference potentiometer, R608.
4-67. Additional fusing on the 250-volt line is con-
tained in the fuse F401. This fuse is included to
protect the driving windings of the yoke, L408 and
LAO9. It is located on the terminal board immedi-
Figure 4-12. Power Supply - Block Diagram ately outside of the RF Unit.
4-7 |
ACEC
