20
R-22GV
R-22GT
R-23GT
R-24GT
former.
During heating, the primary current of the high voltage
transformers also flows through the primary winding of the
current transformer CT1. This causes a current to be
induced in the secondary winding of CT1 and results in an
AC voltage which is determined by R100.
This AC voltage is then half wave rectified by D100 and
smoothed (filtered) by C100.
This AC voltage is the input to the AN3 port of IC1, which
determines if there is a magnetron / high voltage problem.
TB1
TB2
CT1
D100
R102
* R100
C100
47µ/10v
R101
100k
C101
4.7k
To AN3 of IC1
* R100
R22GT/GV---620F
R23/24GT ---820F
Figure T-1. High Voltage Monitoring Circuit
17) Supply Voltage Detecting Circuit
(Applicable to R-23GT / R-24GT only)
This is a circuit for detecting troubles of input voltage at
microwave oven. The function of this circuit is to divide the
variation of voltage across C1 to supply voltage variation
by ZD1, R1 and R2 and to put the result to AN6 port of IC1
for detection.
A 5
A 7
A 3
C1 2200µ/25v
ZD1
R1
470
R2
470
HZ12B1
VRS2
VRS1
(J1)
T1
11ES1 x 4
D1
D2
D4
D3
AC208V
60Hz
AC230V
60Hz
+
-
FIgure T-2. Supply Voltage Detecting Circuit
VOLTAGE REGULATION FOR "ERROR" INDICATION
Voltage
Input to
Input to
regulation
208V
230V
*Normal
+6% excel.
208.0--220.48
230.0--243.8
*Normal
-9% excel.
189.28--208.0
209.3--230.0
*Error.or
+6% to
220.48
243.8
indication
+13% excel.
235.04
259.9
range
-9% to
189.28
209.3
-13% excel.
180.96
200.1
Not
over +13%
over 235.04
over 259.9
cookable
under -13%
under 180.96
under 200.1
* Cookable Range
2. Key Unit
The key unit is composed of a matrix circuit in which when
a key it touched, one of signals P30--P34 generated by the
LSI, is passed through the key and returned to the LSI as
one of signals P24--P27.
This model has 20 Memory pads.
When the oven is shipped, Memory pad 1 to 10 are set as
follows: fig.1.
Memory No.
Cook Time
Output Power
1
10 sec.
100%
2
20 sec.
100%
3
30 sec.
100%
4
45 sec.
100%
5
1 min.
100%
6
1 min. 15 sec.
100%
7
1 min. 30 sec.
100%
8
2 min.
100%
9
2 min. 30 sec.
100%
0
3 min.
100%
(fig. 1)
This model has a double quantity pad. When the oven is
shipped, Magnification "1.8" is preset in the double quan-
tity pad.
This model has an express defrost pad. When the oven is
shipped, express defrost is set as follows: fig.2.
1 STAGE
2 STAGE
3 STAGE
FORMULA
P = 0.2T + 20
P = 0.13T + 30
P = 0.67T - 50
POWER
40 %
30 %
20 %
T : Total cooling time
(fig. 2)
When 1/2 total cooking time is passed, the signal will
sound and "CHECK" indicator will flash.
