R -3A54 
R-3E54 
TOUCH  CONTROL  PANEL  ASSEMBLY 
OUTLINE  OF  TOUCH  CONTROL  PANEL 
The  touch  control  section  consists  of  the  following 
units  as shown  in  the  touch  control  panel  circuit. 
(1)  Key  Unit 
(2)  Control  Unit 
The  principal  functions  of  these  units  and  the  signals 
communicated  among  them  are  explained  below. 
Key  Unit 
The  key  unit  is composed  of  a matrix,  signals  generated 
in  the  LSI  are  sent  to  the  key  unit  through  ROo -  RO 
3,  RIO  -  R13. 
When  a  key  pad  is  touched,  a  signal  is  completed 
through  the  key  unit  and  passed  back  to  the  LSI 
through  R23,  R30  - 
R32  to  perform  the  function  that 
was  requested. 
Control  Unit 
Control  unit  consists  of  LSI,  power  source  circuit, 
synchronizing  signal  circuit,  ACL  circuit,  buzzer  circuit 
and  indicator  circuit. 
‘1) 
2) 
3) 
LSI 
This  LSI  controls  the  key  strobe  signal,  relay  driving 
signal  for  oven  function  and  indicator  signal. 
Power  Source  Circuit 
This  circuit  generates  voltage  necessary  in  the 
control  unit. 
Symbol  Voltage  Application 
VC 
-5v  LSI  (ICI) 
VP  -29v  Fluorescent  display  tube  :  Grid 
and  anode  voltage 
VFI  3Vac  Filament  of  fluorescent  display 
tube 
VF2  (VFI  to  VF2  voltaae) 
Synchronizing  Signal  Circuit 
The  power  source  synchronizing  signal  is  available 
in  order  to  compose  a  basic  standard  time  in  the 
clock  circuit. 
It  accompanies  a verv  small  error  because  it  works 
4) 
ACL  Circuit 
A  circuit  to  generate  a  signal  which  resets  the  LSI 
to  the  initial  state  when  power  is  supplied. 
(RD919A4U) 
5) 
Buzzer  Circuit 
The  buzzer  responsive  to  signals  from  the  LSI  to 
emit  noticing  sounds  (key  touch  sound  and  com- 
pletion  sound). 
6) 
Door  Sensing  Switch 
A  switch  to  “tell”  the  LSI  if  the  door  is  open  or 
closed. 
7) 
Relay  Circuit 
To  drive  the  magnetron,  fan  motor,  turntable  motor 
and  light  the  oven  lamp. 
8) 
Indicator  Circuit 
Indicator  element  is  a  Fluorescent  Display. 
Basically,  a  Fluorescent  Display  is  a  triode  having 
a cathode,  a  grid  and  an  anode.  Usually,  the  cath- 
ode  of  a  Fluorescent  Display  is  directly  heated  and 
the  filament  serves  as cathode. 
The  Fluorescent  Display  has  6-digits,  13-segments 
are  used  for  displaying  figures. 
on  commercial  frequency. 
(RD918A2U) 
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