Tracking Sled Servo System - Samsung MAX-460V Service Manual

Special Circuit Descriptions
5-1-4 TRACKING SLED SERVO SYSTEM (KA9220) : NIC9220
The capacitor between pin 15 and 16 attenuates high frequencies when TG2 is off. The maximum frequency of
tracking phase compensation is inversely proportional to the resistance connected to pin 7 (about 1.2kHz at 470k).
The tracking jump (FWD and REV) is determined when TM3 and TM4 are ON, and the peak voltage induced from
the tracking coil is determined by both TM3 and TM4 currents and the feed back resistance of pin 47.
Track jump max voltage = TM3 (TM4) current x feedback resistance.
0.022UF
51
0.047UF
50
150K
TE 1
52
20K
54
0.1UF
16
0.1UF
15
FWD or REV sled kick occurs when TM5 or TM6 is ON, and the peak voltage added to sled motor
(determined by TM5 or TM6 current and the feedback resistance of pin 41.)
Sled jump max. voltage = TM5(TM6) current x feedback resistance
Each SW current is determined by the resistance connected to pin 22 and 23.
When the resistance is about 150½,
TM3 or TM4 = 11µA,
TM5 or TM6 = 22µA,
This current is inversely proportional to the resistor, variable within a range of t 5 to 40 µA for TM3.
STOP is the ON/OFF detection signal for the limit SW (or the sled motor's innermost cirumference).
5-2
TZC
TZC
100K
1K
BPF
1K
ATC
100K
TE2
470K
DFCT
TDFC1
10K
110K
20K
RTG
82K
TGSW
470K
TG2
S STOP
ATS
TM6
TM5
680K
TM4
66PF
TM3
5.5U
PHASE
COMPENSATION
10K
PFSET
7
470K
180K
22 23
ISET VREG
S STOP
100K
SLED
1K
SLEI
SLEN
10K
5.5U
TM2
TKEI
TKEO
90K
TM7
Samsung Electronics
100K
8
40
56K
SLED
DRIVER
41
39
120K
47
100K
48
TRACKING
COIL