Sony DNW-A75 Maintenance Manual page 53

1 Threading motor FG sensor
This sensor detects the rotation speed of the threading
motor. The output signal of this sensor enters the
threading motor servo circuit, and controls the
threading/unthreading speed to protect the tape during
threading and unthreading operation.
2 Unthreading-end sensor
3 Threading-end sensor
These sensors detect whether the threading ring
reaches the threading-end or unthreading-end position.
4 T tension regulator arm sensor
This sensor detects the position of a T tension
regulator arm. During recording and playback, the
output signal of this sensor enters the T reel motor
servo circuit, and controls the reel torque to keep a
constant T tape tension.
5 Condensation sensor
This sensor detects whether the dew condensation
occurs in the unit.
6 Tape top sensor
This sensor detects the beginning of the tape, and in
addition detects the end of the tape that runs in the
reverse direction.
7 Reel hub diameter sensor
This sensor detects the reel hub diameter detection tab
of a cassette.
The reel hub with two types of diameters (thin and
thick) is available according to the length of a tape
stored in a cassette. This sensor is used to
discriminate the diameter. The output signal of this
sensor enters the servo circuit of take-up and supply
reel motors, and controls the reel rotation speed and
torque during tape transport.
8 Metal/oxide tape sensor
This sensor detects the metal tape detection tab of a
Betacam/Betacam SP cassette.
This sensor is used to discriminate whether the tape
stored in a Betacam/Betacam SP cassette is an oxide
tape or metal particle tape.
9 Tape thickness sensor
This sensor detects the tape thickness detection tab of
a cassette.
This sensor is used to discriminate the thickness of the
tape stored in a cassette.
!/!-!= Cassette classification sensors
These sensors detect the three cassette type detection
tabs of a cassette.
These sensors are used to discriminate whether a
cassette can be used in this unit.
DNW-A75/A75P
![ L cassette (SP) REC inhibit sensor
This sensor (switch) detects the condition of a REC
inhibit plug for the Betacam/Betacam SP large
cassette.
!] L cassette (SX) REC inhibit sensor
This sensor (switch) detects the condition of a REC
inhibit plug for the Betacam SX large cassette.
!\ T reel table FG sensor
This sensor detects the rotation speed of the take-up
reel motor. The output signal of this sensor enters the
reel motor servo circuit, and controls the reel table
rotation speed.
!; Reel S position sensor
!' Reel L position sensor
These sensors detect whether the reel table moves to
the correct position according to the size of the
inserted cassette.
!, S reel table FG sensor
This sensor detects the rotation speed of the supply
reel motor. The output signal of this sensor enters the
reel motor servo circuit, and controls the reel table
rotation speed.
!. S cassette REC inhibit sensor
This sensor (switch) detects the condition of a REC
inhibit plug for the small cassette.
@/ S tension regulator arm sensor
This sensor detects the position of an S tension
regulator arm. During recording and playback, the
output signal of this sensor enters the S reel motor
servo circuit, and controls the reel torque to keep a
constant S tape tension.
@- Tape end sensor
This sensor detects the end of the tape that runs in the
forward direction.
@= Cassette-in sensor (L)
This sensor detects whether a cassette is being
inserted.
@[ Cassette size sensor
This sensor detects whether the inserted cassette is L
size or S size.
@] Cassette-in sensor (R)
This sensor detects whether a cassette is being
inserted.
@\ Cassette-down (2) sensor
@; Cassette-down (1) sensor
These sensors detect the movement (position) of a
cassette compartment by the combination of the
detection state of the two sensors and a cassette-in
sensor.
2-9. Function and Location of Sensors
2-15