Key Matrix - Kenwood KRC-444D Service Manual

KRC-444D/L
CIRCUIT DESCRIPTION
1. KEY MATRIX CONFIGURATION
1-1. Key Matrix Layout
KSg (28)
KSg (25)
KS, (20)
REeaN oN Ree N
SK
The SS in the SSS shows the pin no.
SS
LL] : Momentary switch SS : Diode matrix (closed/opened by diode)
SS
P
YZ : Alternate switch or transistor switch | : Open
LLL
1-2. Switch Connection 1-3. Key Matrix Connection
Momentary switch Alternate switch
Kn
uPD1708G-637-00 KSo
a
KSm KSm
Diode matrix or open Transistor switch
Vop
KSm—
el
: Momentary switch
i
: Alternate switch or
transistor switch
: Diode matrix
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