Sony BVH-2000, Operation And Maintenance Manual

Page: 328 / 505

5..7..4. Outline of Reel Servo
REEL SERVO SYSTEM
HARDWARE
HARD CPU
HOST CPU
The reel servo is responsible for controlling the tape tension at
the S (Supply) and the T (Take-up) sides and for controlling the
Sand
T reel acceleration or deceleration.
The tape tension is detected by the Sand T tension arms and, in
accordance
with the mode, the tension is controlled the
hardware and CPU so that its value is optimum. The tape
tension is made even stabler by detecting the winding diameter
of the tape by the Sand
T reel FG data
During acceleration or deceleration, the transitional motor
torque necessary for control is calculated by the HOST CPU,
based on the command, reel inertia and tape diameter
data, and applied via the tension feedback system.
The timer roller FG are output in two A and
FG B) and the speed is detected by their time difference. In the
I x normal speed mode, the timer roller outputs a frequency
corresponding
to the V
In order to maintain the accuracy of the timer count and guard
against the effects of timer roller slippage and variations
in
diameter, the timer roller compensated for REC CTL
in the recording mode and by PB CTL in the playback mode,
and the timer pulse obtained
The CTL-compensated timer pulses are supplied to the system
control system and used for timer display.
BVH-2000(U/C)/PS/PM
BVH-2180(U/C)/PS/PM
5-7-5
SERVO SYSTEM