18
R-25AM
2. Switch Unit
The switch unit is composed of a matrix circuit in which
when a switch it touched, one of signals P30 - P31
generated by the LSI, is passed through the switch
and returned to the LSI as one of signals P24 - P26.
3. Encoder
The encoder converts the signal generated by power
source circuit into the pulse signal, and the pulse
signal is sent to the LSI.
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) Control Unit
(2) Switch Unit
(3) Encoder Unit
The principal functions of these units and the signals
communicated among them are explained below.
1. Control Unit
Signal of key touch and oven function control are all
processed by one microcomputer.
1) Power Supply Circuit
This circuit changes output voltage at the secondary
side of the touch control transformer to voltages re-
quired at each part by full wave rectifying circuit,
constant voltage circuit, etc..
2) Reset Circuit
This is an Auto-clear Circuit, i.e., a reset circuit, which
enables IC1 to be activated from initial state.
3) Power Synchronizing Signal Generating Circuit
This is a circuit for generating power synchronizing
signal by virtue of the secondary side output of touch
control transformer.
This signal is used for a basic frequency to time
processing and so on.
4) Clock Circuit
This is a circuit for controlling clock frequency required
for operating I-1.
5) I-1 (Main Processor)
This is a one-chip microcomputer, responsible for
controlling the entire control unit.
6) I-2 (Memory Processor)
This is a memory IC, responsible for memory function.
7) Display Circuit
This is a circuit for driving display tubes by I-1 output.
8) Switch Input Circuit
This is a circuit for transmitting switch input information
to I-1.
9) Sound-body Driving Circuit
This is a circuit for driving sound body by I-1 output.
10) Relay Driving Circuit
This is a circuit for driving output relay by I-1 output.
11) Stop Switch Circuit
This is a circuit for driving I-1 to detect door opening/
closing.
12) Exhaust Air Temperature Detecting Circuit
This is a circuit for transmitting output change of
thermistor (Exhaust thermistor) to I-1.
13) Magnetron Temperature Circuit.
(Detect Noload or Fan Lock)
This is a circuit for transmitting output change of
thermistor (Magnetron thermistor) to I-1.
