Sharp R-4H56, Service Manual

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20
R-4H56
26 H1 IN Signal similar to H0.
When any one of G-11 line keys on key matrix is touched, a corresponding signal will
be input into H1.
27 H2 IN Signal similar to H0.
When any one of G-10 line keys on key matrix is touched, a corresponding signal will
be input into H2.
28 H3 IN Signal similar to H0.
When any one of G-9 line keys on key matrix is touched, a corresponding signal will
be input into H3.
29 H4 OUT Digit selection signal.
The relation between digit signal and digit are as follows;
Digit signal ........................ Digit
H4 ...................................... 1st.
H5 ..................................... 2nd.
H6 ....................................... 3rd.
H7 ...................................... 4th.
F0 ...................................... -5th.
B0,B1 .................................. 6th.
Normally, one pulse is output in every ß period,
and input to the grid of the Fluorescent Display.
30-32 H5-H7 OUT Digit selection signal.
Signal similar to H4.
33 VPP IN Anode (segment) of Fluorescent Display light-up voltage: -25V
Vp voltage of power source circuit input.
34 F0 OUT Digit selection signal.
Signal similar to H4.
35-36 B0-B1 OUT Digit selection signal.
Signal similar to H4.
37 B2 OUT Segment data signals.
The relationship between signals and indicators are as follows:
Signal Segment Signa Segment
B2 ........... LB G0 ............... f
G6 .......... UB B7 ................ e
G5 ............ k B6 ................ d
G4 ............. j B5 ................ c
G3 ............. i B4 ............... b
G2 ............. h B3 ............... a
G1 ............ g
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to H0 - H3 terminal while
one of G-1 line keys on key matrix is touched.
38 B3 OUT Segment data signal.
Signal similar to B2.
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to H0 - H3 terminal while
one of G-2 line keys on key matrix is touched.
39 B4 OUT Segment data signal.
Signal similar to B2.
P22
ß(50Hz)
H
L
GND
VP
P17
P14
P06
P02
P37
Pin No. Signal I/O Description
ß(50Hz)
GND
VP