Kenwood DP-3010 Service Manual page 38

DP-3010
70
CIRCUIT DESCRIPTION
By switching the two analog switches (TEL1 and 2)
ON/OFF, by fixing the gain from the Tracking Servo Open
Loop the Tracking Gain Adjustment System will take the
Shock and Defect Detection Selectivity to be done equally
{Tracking Error Signal Amplitude is fixed). Also to aquire
the Zero Cross Timing of the RF Signa! (needed informa-
tion during Tracking Search} the Slice Level is calculated.
The three command used are TGASS, TGASR and
TGASET. The TGASS command is the electrical value of
VDD2 from the FKIC pin and the TGASR command is the
Vss electrical value. This means the Tracking Actuator is
moved around internally and externally. During the input
of these two commands, TEL1 and 2 are forcefully set to
HiZ while the SEL pin is "L" level. When the SEL pin =
"L", the Observation Signal from the Servo IC, TA8101N, is
input in which the ZCL1 side is a TE signal and the ZCL2
side is the RFRP signal. When TGASS and TGASR com-
mands are input, the TE signal of the ZCL1 side is put into
Peak Data Hold Mode and when TGASET command is
input, the Peak Data is decoded and set to TEL1 and 2.
TEL1 and 2 go on to be used, as shown in the System Con-
struction Diagram (Diagram 7-24), to adjust the TSO
amplitude to about 0.8 Vp-p. The intervals and number of
times of TGASS and TGASR commands is set by the CPU
and the TGASET command is output once.
Note: When the Tracking Gain Adjustment System is
tun, it is taken for grantéd that the CLV Servo is in
operation when the DMSV command is input.
The reason for this is that during Tracking Gain Ad-
justment, the RFRP signal is used to observe the
Focus condition.
For further information about Tracking Search Operations,
refer to Page 81, (d) CPU Process Flow Chart of Focus
Search Method.
BCD | PeakData TEL 1 TEL 2
0 +©10000=*-;*~C«<'(.U!SCdS
Nn 100011 1
[2 ooo. 1 41
B 10011 I 7"
M 10100 L
15 10102 isd
16 | 10110 0 1
ie: iat. = 0. k e
18 11000 1 0
19 | 11001 1 0
1A | 11010 0 0 |
1B 11011 0 0
iC, 11100 0 0
1D 11101 0 0
1E '11110 0 0
IF moO Oo |
O;HIZ 1: Veer
Chart 7-6 TE Signal Peak Hold Data Decode Chart
DP-3010
CIRCUIT DESCRIPTION
The Focus Servo is unlatched
Defect (Scratch) b—- due to extemal disturbance.
+F2 Level
2CL2
SBA LLL LL LI LLL LLL
peal TIILIT IIL IL ITLL ITZ. SOSET Command
FOK
L
64msec —~——wd
Less than 64 msec fee Focus Servo judged to be unlatched.
Z The Focus is unlatched
I Tracking Servo OFF due to external disturbance.
ZCL2 c1011
(RFRP)
FOK
64msec —+|
Less than 64 msec
Diagram 7-26 SBAD and RFRP Signal Focus ON/OFF Comparison Signal
- SBAD —————_RFRP ep SBAD
01011
[Sa Ta
i
Since the Disc Motor Start-up is stow,
RFRP is not emitted.
FOK H |
t_ Servo is OFF.
Command fly
28
z 3 (Bad Example)
pe
SBAD +} RERP
FOK
H
TDM "~~ Disc Motor Start-up Time
~1
{Good Example}
DMSV
TGASS
TGASR
Diagram 7-27 RFRP Signal Output Waveform during Disc Motor Servo ON (DMSV Command Set)
71