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6.7.4. BELL DETECTION CIRCUIT (Change from original page 156.)
1. Circuit Operation
The signal wave from of each section is indicated below. Signal (low level section) input to pin 29 of gate array IC5 is read
out at the CPU and judged as a bell.
Between A wire and S write
Between PC2 (1) and (2)
PC2 (4) / Gate Array IC5 (29)
TEL LINE
PC(1, 2)
PC2(4)
6.7.5. PULSE DIAL CIRCUIT
1. Circuit Operation
In the OFF-HOOK Condition, the photocoupler PC3 pin (2) is a low level by the IC5 pin (2), and the PC3 pin (4) is a low level
if Q3 is ON. During the pulse dial operation, the PC3 pin (2) becomes a high level by the IC5 pin (2), so that the PC3 pin (4)
becomes a high level. If Q3 is ON, then the line is ON and vice versa. The high/low control for the IC5 pin (2) makes the
pulse dial operation possible.
IC5 (2) High Level
PC3 (2) High Level
6.7.6. TAM INTERFACE CIRCUIT
This circuit is to switch between FAX receiving and the external TAM's message recording automatically. This circuit
consists of an EXT. TAM OFF-HOOK detect circuit, monitor transformer, multiplexer, amplifer, and VOX detect circuit.
For details, please refer to 9. TAM INTERFACE SECTION.
IC5(29)
PC3 (4) High Level
(Model KX-FP300E)
11
48V
Q3
TEL LINE
KX-FP300E
about 150V
1.5V
0V
1.5V
5V
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