Sony DVP-M35 Operation Manual page 37

The sled error signal is passed through the digital filter in IC506 (DSP), and output
from the DSP as the SOUT (@P) signal from the D/A converter.
The SOUT signal is input to DVI (@P) of the sled drive IC (IC302:LA6527N).
The sled drive IC incorporates a speed (motor rotation speed) feed back control using
the Hall element.
There are two speed detection Hall elements (HA, HB). The detection output is obtained
from the sled motor board (FG-43 board) as the differential output of (HA+, HA-)
The sled drive IC detects the inclination of the Hall element output waveform during
sled motor rotation (differential value near the zero cross) to form the speed feedback.
In the sled drive IC, after the sled error signal is converted to the sled motor rotation
speed signal, the voltage and current are amplified, and the sled (d.c.) motor is driven
by the output signal (SLDMT+ @P, SLDMT- @P).
(2) Sled forced operation control
When driving the sled motor in operations other than playback, in other words during
direct search, the sled speed target signal is input from IC506 (DSP:CXD8730R) @P
SDCNT to the sled motor driver IC302 (LA6527N) @P. The data to IC506 (Servo
DSP) is sent from the IC805 SH microcomputer.
The IC506 SLOFS @P is the offset adjustment signal of IC302. It is used to adjust the
voltage supplied between the motor terminals to 0 when the sled motor is stopping.