Table of Contents
Advertisement
Circuit Explanation
suitable for M sound signal. The IF signals which have passed through sound carrier deep trap by
sound surface filter will be sent to the (23) and (24) of N201 TDA9373 . HF amplification AGC will
2
be sent out from the (27) of N201 TDA9373
under the control of I
C bus for the gain control of HF
tuner.
2.4 Analysis of signal trap option switch circuit
Video color signals will be sent out from (38) of N201 TDA9373 and emit and followed by triodes
V208 and
V209, and then, divided into sub-flows which are fed into the wave traps Z201~Z204 respectively. All
TV signals will be selected and pass through V210 and V211, which are rejector triodesand serve the
function of switches here. When the 6 pins of N201(TDA9373) export high level with sound below
4.5M, V211 will break over and the signals will pass through the wave traps Z201~Z202; and when
the 6 pins send out low level with sound of 4.5M, V211 will stop and V210 break over, and the signals
will go through the wave traps Z203~Z204. Video signals will be produced after all TV signals are
trapped by the wave trap, and then, one sub-flow will go through R255 430
and R256 470
for signal adjustment amplitude and enter into (40) of N201 TDA9373 , and another sub-flow will,
after emit and followed by a triode V212, serve as AV output.
Both the video signal in AV signals and the Y signal in S terminal signals will be selected and passed
through by N702 HEF4053BP , and will then be fed into the (42) of N201 TDA9373 ; and the C
signal of S terminal will be fed into the (43) of N201 TDA9373 . Both the AV1 and AV2 video signals
and the Y signal of S terminal will be selected and passed through by N702 HEF4053BP under the
control of the (62) and (63) of N201 TDA9373 .
The DVD component terminal Y, U and V signals will be coupled by the capacitors C001 10u ,C006
10u and C005 10u and fed into the (47), (48) and (49) of N201 TDA9373 respectively.
2.5 Analysis of sound tone processing circuit
The sound tone processing circuit is comprised of an integrated circuit N701
TDA9860
and
peripheral components. TDA9860 is a multi-function TV sound tone processing integrated circuit of Hi-Fi
grade, inside which treble and bass frequency division processing, stereo processing and encircling
sound processing are made.
The audio signals sent out by the (44) of N201, after emit and followed by V213 and passing through
a coupling capacitor C706 224 , will be divided into two sub-flows which enter into the (3) and (5) of
N701 TDA9860 respectively. Meanwhile, the audio signals from the left and right channels of AV1
terminal will be put into the (1) and (32) of N701 TDA9860 . The audio signals of S terminal and AV1
share the same sub-flow. The audio signals from the left and right channels of AV2 terminal will be
put into the (28) and (30) of N701 TDA9860 . The audio signals of DVD component terminal and
AV2 share the same sub-flow.
As for TV or AV audio signals that have been selected and go through inside N701 (TDA9860) without
sound tone processing, the independent audio signal of left and right channels and exported directly
33
Advertisement
Table of Contents
