ER-A490 (serv.man2). ERA490 Service Manual - Sharp ECR Service Manual (repair manual). Page 34

The infra-red signals which was transmitted from the transmission unit
through the air is received by the photo diode, and sent through the
two-system circuit to the MPCA6, where they are modulated and in-
putted to the CPU. 

With the IRTX signal from the MPCA6, Q2 is turned on/off to light
LED1, 2. To strengthen the light intensity, two LED’s are used.

PD

Amplifier

Band-pass
filter

Hysteresis
comparator

ASK

AGC
Amplifier

Bypass
filter

Hysteresis
comparator

IRDA
/REMOCON

+5V

R67

R70

IC1A

R69

C49

C61

R51

R52

R53

IRDA
/REMOCON

MPCA6

C45

Q2

R54

R55

R68

PD1

R56

MPCA6

R56

PD1

R56

R57

C46

R58

R68

R59

Q2

C47

R60

C48

R62

R61

C49

R66

R64

R63

R69

R70

R67

IC1B

C50

R65

+5V

ASK

Q2

LED2

LED1

R72

+5V

R71

IRTX

MPCA6

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