Sharp R-2277 Service Manual page 22

R-2277
R-2287
Pin No. Signal I/O
26 INT0 IN
27 RESET IN
28-29 P71-P70 OUT
30 XIN IN
31 XOUT OUT
32 VSS IN
33 P27 OUT
34 P26 OUT
35-36 P25-P24 OUT
37-38 P23-P22 OUT
39-48 P21-P10 OUT
49-54 P07-P02 OUT
55-56 P01-P00 OUT
Signal synchronized with commercial power source freqency.
This is basic timing for all time processing of LSI.
Auto clear terminal.
Signal is input to reset the LSI to the initial state when power is supplied.
Temporarily set to "L" level the moment power is supplied, at this time the LSI is
reset. Thereafter set at "H" level.
Terminal not used.
Internal clock oscillation frequency setting input.
The internal clock frequency is set by inserting the ceramic filter oscillation circuit
with respect to XOUT terminal.
Internal clock oscillation frequency control output.
Output to control oscillation input of XIN.
Power source voltage: -5V.
VC voltage of power source circuit input.
Oven lamp, Blower motor and Stirrer motor driving signal (Square Wave-
form : 50Hz).
To turn on and off the shut-off relay (RY1).
The Square waveform voltage is delivered to
the RY1 relay driving circuit and relays
(RY2, RY3 COOK RELAY) control circuit.
Terminal not used.
Magnetron high-voltage circuit driving signal.
To turn on and off the cook relay. In100% power level operation, "L" level during
cooking; "H" level otherwise. In other power level operation (50, 20, or 10%), "H"
and "L" level is repeated according to power level.
P0WER LEVEL ON
50% 26sec.
20% 12sec.
0% 8sec.
Terminal not used.
Segment data signal.
The relation between signals and indicators are as follows:
Signal Segment Signal
P01 ................... i P15 ..................... f
P00 ................ j,k P14 ....................e
P21 ............... LB P13 ....................d
P20 ............... UB P12 .................... c
P17 .................. h P11 ....................b
P16 .................. g P10 ....................a
Digit selection signal.
The relation between digit signal and digit are as follows:
Digit signal
P07
P06
P05
P04
P03
P02
Normally, one pulse is output in every ß
period, and input to the grid of the Fluores-
cent Display.
Segment data signal.
20
Description
OFF
22sec.
36sec.
40sec.
Segment
ß(50Hz)
Digit
1st.
ß(50Hz)
2nd.
3rd.
P07
4th.
5th.
P06
6th.
P05
P04
P03
P02
OFF
GND
ON
-5V
32 sec.
During cooking
20 msec
OFF
GND
ON
-5V
48 sec.
GND
VP
H
L
GND
VP
GND
VP
H
L