Sharp R-9320 Service Manual page 50

R-9320
R-9450
BUZZER CIRCUIT
The square
waveform developed from T terminai of LSI is
applied
to the base of Q6 to turn on and off Q6, and square
waveform voltage (2.5 kHz) is applied to SPl to generate
buzzer sound.
Cl6
r
---------
1
T
SPl
GND
GND
200usec. 1 200usec.
I
Figure 13. Buzzer Circuit
RELAY CIRCUIT
While the unit is in cooking, "H" level signal
is produced
on the control relay (R L2).
at 08 terminal of LSI and also a pulse signal at D9
terminal
The "f-i" level signal from D8 terminal is applied to Q2 which
of LSI. The pulse signal from D9 terminal is applied to
the
rectifier circuit made up of
082
and 083
where it is made
is connected in series with 03, and current i2 is caused only
when both
02
and
Q3
are turned on at a time and it allows
into DC signal to charge C81. With C81 charged up, Q4 and
Q3 turn on in succssion so that a current il
is
caused
to turn
the cook relay (RLl) to turn on.
240V
50Hz
RLl
I
Tl
i
ID5 Rl
I
Figure 14. Relay Circuit
48