Panasonic NV-HV61EE, Service Manual

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49
10-6-3. Detecting reel lock
During tape running such as PLAY, CUE/REV or FF/REW, if reducing tape speed or reel mount stop is detected, these are
recognized as reel lock. In this case, in order to protect tape and capstan driver, switch the VCR mode to STOP, or switch the
tape running drive to capstan drive from reel drive.
Reel lock detection time is different depends on the mechanism position or capstan speed, in order to minimize the tape quantity
which is wound between when the reel lock has occurred on take-up side and when the lock is detected by IC6001.
(1) PLAY, CUE/REV mode (PLAY/REV position)
In each running mode, if reel pulse edge is not input for period shown in the table below after finishing the mode change, reel
lock is detected and mode changes to STOP mode.
NTSC PAL
Speed VCR mode Times Value Speed VCR mode Times Value
PLAY ± 1 3.5s PLAY ± 1 3.5s
± 2, 5 1.6s ± 2, 5 1.6s
± 7,9 0.3s ± 7,9, 11 0.3s
2H
CUE/REV
± 11 0.2s
3H
CUE/REV
± 15 0.2s
PLAY ± 1 3.5s PLAY ± 1 3.5s
± 2, 5 1.6s ± 2, 5 1.6s
± 9, 11, 13 0.3s ± 11, 15, 17, 19 0.3s
4H
CUE/REV
± 13 0.2s
6H
CUE/REV
± 27 0.2s
PLAY ± 1 3.5s PLAY ± 1 5.1s
± 2, 5 1.6s ± 2, 5 2.66s
± 11, 21, 27 0.3s ± 11, 15, 17, 19 0.5s
6H
CUE/REV
± 35 0.2s
9H
CUE/REV
± 35 0.34s
PLAY ± 1 5.1s
± 2, 5 2.66s
± 11, 21, 27 0.5s
10H
CUE/REV
± 35 0.34s
(2) FF/REW mode (FF/REW position)
If one of the following conditions exists, reel lock is detected. Rotation mode changes to Pinch roller mode (FF changes to CUE,
and REW changes to REV), and rotation continues.
1. When more than 5 sec. has passed after moving to FF/REW position and waiting for reel pulse detection in supply side.
2. When reel pulse is not detected for more than 2 sec. Continuously after 5 sec. passed since the mechanism mode has
finished to change (process number =0). (common to Full and C)
3.
When reel pulses is not detected for more then 800 ms continuously after 5 sec. passed since the mechanism mode has
finished to change. (common to Full and C)
Tapes running pattern and lock detection
Thin hub: 4.5m/s
Wide hub: 4.5m/s
C cassette: 1.3m/s
Steady speed control
Capstan 6 times speed
FF/REW start
Full acceleration
1 deceleration
Capstan 1.3 times speed
2 deceleration
Pitch start
End edge
Watching supply reel.
3 Pitch start is shifting
5sec.
Mechanism shifts
Watching lack of reel pulse for more than 800msec.
(Common to Full cassette and C cassette.)