Sharp R-24AT, R-22AT Touch Control Panel Assembly, Key Unit, Control Unit, Power Supply Circuit

R-22AT

R-24AT

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)Key Unit

The principal functions of these units and the signals communicated among them are explained below.

2. Key Unit

The key unit is composed of a matrix circuit in which when a key it touched, one of signals P33 - 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.

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)Key Input Circuit

This is a circuit for transmitting key 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.

Memory No.	Cook Time	Output Power
1	5 sec.	100%
2	10 sec.	100%
3	20 sec.	100%
4	30 sec.	100%
5	40 sec.	100%
6	50 sec.	100%
7	1 min.	100%
8	1 min. 15 sec.	100%
9	1 min.30 sec.	100%
0	2 mins.	100%

(fig. 1)

This model has a double quantity pad. When the oven is shipped, Magnification "1.8" is preset in the double quantity pad. This model has an defrost pad. When the oven is shipped, defrost is set as follows: fig.2.

	1STAGE	2STAGE	3STAGE
POWER	40%	30%	20%
DEFROSTING TIME	0.2T+20sec	0.13T+30sec.	0.67T-50sec.

(fig. 2)

NOTE :

"CHECK" indicator will flash at half of defrosting time.

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