Aiwa DX-D91 Service Manual page 16

KEY MATRIX KEY SWITCH INPUT VOLTAGE
QLTAGE 0 ~0.33 | 0.82~1. 29 | 1. 78~2, 21 | 2. 69~3, 06 | 3.56~4, 06
(SWI) (SW2) (SW3) (SW4) (SW5)
jroo | os | et | |e |
REPEAT PROGRAM
FW50 DISPLAY DELETE +10
© | PSP | auawe_| ce
STOP PLAY
FW501 PAUSE AUTO NDOM
/CLEAR /REPLAY jm | mo |
OPEN F-BWD FeFWD
FW501 CONT,
evose | _/B-sxie | /P+SKIP pom f=
PEAK SEARCH CIRCUIT
@ AD START Input signals coming from @ are amplified by IC651 (1/2) ani
V
¥ fe occ | | at the leading edge of AD START @. When the voltage of @
0 is lower than that of ©, the output signals of 1C651 (2/2)
are inverted. The smaller the number of WDCK sighals input
COMP pi Sk ke
® SV to pin @ of 1€201 from the leading edge of AD START to the
0 | trailing edge of COMP, the greater the peak is judged to be.
are peak hold at ©, The voltage of @ is discharged through R657
That point is then recorded. The P*HOLD signals are discharjed
whenever the voltage of the peak hold circuit is measured.
eee A Sie ae . '
0 t
@ Sound signal/ Discharge when P-HOLD is 1".
Rect ification Oe ees ee
input ov
P.
pees ie | cma ey ae | a
@® Discharge TE
22