Teac PD-135 - Safety Interlock

SAFETY INTERLOCK
The Digital Compact Disc Player reads the disc signal by
' detecting the laser beam. It must be avoided for the human body
to directly receive the beam. Especially human eyes are badly
affected by the beam. Therefore, the unit is equipped with an
interlock to prevent the unnecessary laser outputs.
The laser outputs are controlled by the injection or cutoff of the
constant voltage source to the laser diode with Pin 23 of IC 103
(LC6523H). When Pin 23 is in “L” (Low) level, the laser emits the
beam. When Pin 23 is in “H” (High) level, the laser does not emit
the beam.
Pin 23 is set in “H” level when the unit is loaded with the disc
and it reads the index signals or when the unit is set in the play
mode after that. When the unit reads the index signals and the
:
IC103
W103
LOADING
LIMIT
LC6523H
SWITCH
PLAY
SWITCH
~13-
following two conditions are met, the laser emits the beam.
1) When the Loading Limit Switch is set in “CLOSE” side. (The
disc tray is closed.)
2) The pickup is located at the area of the minimum internal
circumference.
After the above conditions are met and the index signals have
been read, the laser emits the beam when the following two
conditions are met.
1) When the PLAY button is pressed.
2) When the PLAY indicator is ON.
CONSTANT VOLTAGE
POWER SUPPLY
AUTOMATIC
LASER
POWER
CONTROL.
AC POWER SOURCE
D512
DISPLAY