KX-FP300E - Panasonic Fax Service Manual Simplified (repair manual). Page 11

11

(Model KX-FP300E)

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.

TEL LINE       PC(1, 2)      PC2(4)      IC5(29)

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      PC3 (4) High Level       Q3       TEL LINE

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.

about 150V

0V

1.5V

1.5V

5V

48V

Between A wire and S write

Between PC2 (1) and (2)

PC2 (4) / Gate Array IC5 (29)