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KRC-949D
CIRCUIT DESCRIPTION
Mechanism control in Mode transition
When shifting from one mode to another, this unit con-
trols the mechanism by driving the FWD/REV or FF/REW
motor,
For this purpose,
!C1 determines
its current mode
by using the S807 on the FR drive gear and the S806 on
the PLAY drive gear.
After finding
in which
mode the unit is, it drives the
FWD/REV
and
FF/REW
motors with the contro! signals
from
pins 36 through 39 of IC1 to shift the mechanism
to the new mode. The right table lists the unit modes and
the state of each of the related terminals.
Either of FF/REW or FWD/REV
is detected depending
on whether pin 17 or 18 of IC1 is "L"; when pin 17 is "L",
the unit
is in the FWD
or REV
mode.
This detection
is
mode
in each
program
scan
and
the resultant
data
are
used for the subsequent mode transition.
By lowering either pin 17 or 18 to "'L"', the current state
of the S806 and S807 switches (this also allows a check on
their function).
SYNTHESIZER UNIT (X14-2002-70)
Mode
aad
K3 |
Ké4
(3)
(4)
REW or
REV overrun
1
1
urn is detected.
REW or REV
REW or REV
STOP
FF or FWD
STOP
FF or FWD
overrun
1
Excess switch turn is detected.
17
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