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 com- municated 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 P00 - P07.
When a key pad is touched, a signal is completed through the key unit and passed back to the LSI through R24 - R27 to perform the function that was requested.
Control Unit
Control unit consists of LSI, power source circuit, synchro- nizing signal circuit, ACL circuit, buzzer circuit, relay circuit and indicator circuit.
1)LSI
This LSI controls the key strobe signal, relay driving signal for oven function and indicator signal.
2)Power Source Circuit
This circuit generates voltages necessary for the control unit from the AC line voltage.
Symbol | Voltage | Application |
|
|
|
VC | LSI(IC1) | |
VP | Fluorescent display tube : Grid | |
|
| and anode voltage |
3)Synchronizing Signal Circuit
The power source synchronizing signal is available in order to compose a basic standard time in the clock circuit. It incorporates a very small error because it works on commercial frequency.
4)ACL Circuit
A circuit to generate a signals which resetting the LSI to the initial state when power is applied.
5)Buzzer Circuit
The buzzer responds to signals from the LSI to emit audible sounds (key touch sound and completion sound).
6)Door Sensing Switch
A switch to inform the LSI if the door is open or closed.
7)Relay Circuit
To drive the magnetron, fan motor, stirrer motor, turnta- ble motor, hood motor, and light the oven lamp and hood 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 cathode of a Fluorescent Display is directly heated and the filament serves as cathode.
The Fluorescent Display has
Filament of fluorescent dis- | |
| play tube |
| (VF1 to VF2 voltage) |
|
|
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