Panasonic VL-GD001RU Service Manual ▷ View online
11 CIRCUIT OPERATION
11.1. Outline
Handset consist of the following ICs as shown in BLOCK DIAGRAM (P.40).
•
DECT BBIC (Base Band IC): IC1
−
Controlling the DECT specific physical layer and radio section (Burst Module Controller section)
−
ADPCM codec filter for speech encoding and speech decoding (DSP section)
−
Clock Generation for RF module
−
ADC,DAC, timer and power control circuitry
−
All interfaces (ex: Key, Detector Circuit, Analog Front End, EEPROM, LED, Relay)
•
CPU: IC2 (for Doorphone i/f)
−
Detector
−
Sound generator (making chime sound)
−
Analog switch controller
−
Relay controller
•
RF Module: CN6
−
PLL Oscillator
−
Detector
−
Amplifier for transmission and reception
•
AMP: IC3, IC4
−
Signal OP_AMP
•
EEPROM: IC8
−
Temporary operating parameter (for RF, etc.)
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11.2. Power Supply Circuit
Circuit Operation:
The power is supplied to the DECT BBIC, RF module, CPU, OP_AMP, Analog switch and EEPROM as shown in Fig.114. The
power supply is as follows:
power supply is as follows:
•
DECT BBIC (IC1):
CN9 (+9V)
→
D1
→
IC7
→
Q10
→
IC1
•
RF Module (CN6):
CN9 (+9V)
→
D1
→
IC7
→
Q19
→
RF module (CN6)
•
CPU(IC2):
CN9 (+9V)
→
D1
→
IC6
→
IC2
•
AMP(IC3):
CN9 (+9V)
→
D1
→
IC3
•
AMP (IC4):
CN9 (+9V)
→
D1
→
IC4
•
EEPROM(IC8):
CN9 (+9V)
→
D1
<Fig.114>
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VL-GD001RU
11.3. Incoming Detection Circuit
Circuit Operation:
When the Doorphone Call button is pressed, the signal is transmitted like CN1
→
IC2 (12)
→
IC2 (20)
→
IC1 (28)
→
CN6
→
DECT Base, and the signal is detected by DECT (incoming call of Doorphone).
11.4. Back Tone Sending-out Circuit
Circuit Operation:
When the incoming signal of Doorphone is inputted into IC2, ping-Dong sound from IC2 (10) is sent out in the following route
IC2(10)
IC2(10)
→
IC3
→
RLY1
→
CN1
→
doorphone.
11.5. Voice Path Formation Circuit
Circuit Operation:
After incoming call of Doorphone is transmitted to DECT, with sending out a voice path formation signal in the route of DECT
→
CN6
→
IC1(34)
→
IC2(24)
→
IC2(4)
→
RLY1 and switching the route of a relay in order to carry out intercom correspondence
from DECT, a voice path is opened and a telephone call is started. After a telephone call is completed, a signal will be sent in
the same route to close a voice path.
the same route to close a voice path.
11.6. Door Opener
The electric lock connected among S1-S2 of CN1 can be opened the lock during a telephone call by DECT. If a opening lock
button is pressed, the signal of electric opening the lock will transmit to a relay from DECT, and a relay will be operated. Then,
between S1-S2 are sorted and an electric lock opens in the meantime. When constant time (5 sec.) passes, it stops putting out
the signal which operates a relay and the electric lock is locked.
button is pressed, the signal of electric opening the lock will transmit to a relay from DECT, and a relay will be operated. Then,
between S1-S2 are sorted and an electric lock opens in the meantime. When constant time (5 sec.) passes, it stops putting out
the signal which operates a relay and the electric lock is locked.
11.7. Transmitter/Receiver
The set mainly consist of RF module and DECT BBIC.
The set Transmit/ receive voice signal and data through the antenna on carrier frequency.
Signal Path:
*Refer to SIGNAL ROUTE (P.44).
11.7.1. Transmitter Block
The voice signal input from the door phone interface goes to RF Module (CN6) through DECT Base Band IC (IC1) as shown
in BLOCK DIAGRAM (P.40)
in BLOCK DIAGRAM (P.40)
The voice signal passes through the analog part of IC1 where it is amplified and converted to a digital audio stream signal. The
burst switch controller processes this stream performing encryption and scrambling, adding the various other fields to produce
the GAP standard DECT frame, assigning to a time slot and channel etc....
burst switch controller processes this stream performing encryption and scrambling, adding the various other fields to produce
the GAP standard DECT frame, assigning to a time slot and channel etc....
In CN6, the carrier frequency is changing, and frequency modulated RF signal is generated and amplified, and radiated from
antenna.DECT base unit detects the voice signal or data signal in the circuit same as the following explanation of Receiver
Block. And forwards other handset. A voice from Doorphone is sent to DECT base unit as a radio signal by RF module, and the
base unit will transmit the signal to a handset like a intercom call, then the communication will be possible between DECT and
Doorphone.
antenna.DECT base unit detects the voice signal or data signal in the circuit same as the following explanation of Receiver
Block. And forwards other handset. A voice from Doorphone is sent to DECT base unit as a radio signal by RF module, and the
base unit will transmit the signal to a handset like a intercom call, then the communication will be possible between DECT and
Doorphone.
11.7.2. Receiver Block
The signal of 19.2MHz band (1881.792~1897.344MHz) which is input from antenna is input to CN6 as shown in BLOCK
DIAGRAM (P.40).
DIAGRAM (P.40).
In CN6, the signal of 19.2MHz band is downconverted to 864kHz signal and demodulated, and goes to IC8 as DECT frames.
It passes through the decoding section TDD(Time Domain Duplex)/ TDM(Time Domain Multiplex) controller where it separates
out the frame information and performs de-encryption and de-scrambling as required. It then goes to the DSP section where
it is turned back into analogue audio. This is amplified by the analogue front end, and goes to the Doorphone Interface.
It passes through the decoding section TDD(Time Domain Duplex)/ TDM(Time Domain Multiplex) controller where it separates
out the frame information and performs de-encryption and de-scrambling as required. It then goes to the DSP section where
it is turned back into analogue audio. This is amplified by the analogue front end, and goes to the Doorphone Interface.
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12 SIGNAL ROUTE
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