Sony PS-X75 - Automatic Disk Size Detection Circuit

5V
ov
ie]
ARM LIFTER DOWN
| PS-X75
Bt
= Q108
UT OF ZERO BALANCE.
ST @
0 1) STYLUS FORCE
Og7>39
ae Tepe at avaoe
TO
HORIZONTAL-
[-D
9
DRIVE CIRCUIT FSO =
Bt
1C109 er
ce oO”
sas @-O-}>-O+Omn | |S
aie ote a.
Mma bd
2] & 1502
iaioe al Com &
7 B
STYLUS FORCE 2 9 Q122
NE
39 Bt <I
0133
eae er
BALA @ ©) Le 6) tO) i> Q132
5 Vv \ ci _
1C102 oie 1C103
kay
WITHIN ZERO ; B-
BALANCE Fig. 4
(ARM LIFTER DOWN)
1-4-5, Automatic Disk Size Detector (see Fig. 5):
As long as the turntable is rotating, the light from
PLS501 passes through the prism on the turntable
mat and switches phototransistors Q501 and Q502.
The outputs of Q501 and Q502 are fed to termi-
nals (30) and (31) of IC102 to be used for automatic
detection of the disk size.
when no record
placed —--~
SS
when a record p+
placed: OV
when no record ___
placed i [| |
OV
when a record placed: 0V
[Nodsk | 1 | St *d Cn
Ee ee ee ee ee e when a record plaed: 0
when no record paced: 7
Q502
PL501 Le
B-
Fig. 5