Panasonic Va-208 Key Telephone System Installation Manual

							Service Check Point-7 
No hold tone. . . . . In case of TEL A-K communication is normal 
(1) Does RL5 operates by the hold data from TEL? 
. . 
; 
22 I 
I 
23 I I 
IC4 
Does it output @ Dbes it operates on hold.? 
status on hold? Does it output 0 status? 
(2) Does it output the hold tone? 
In case of COLI hold. Does it output the 
hold tone? 
f 
Hold tone 
transmit circuit 
24 
1 2 
IC4 
I COL2 
25 
I 
I 
I 
I I : 
Does it output 0 status Does it output @ status 
when sending the hold tone? 
when sending the hold tone? 
- 28 -  
						

							Service Check Point-8 
Can not CO call originate (DP). . . . . In case of the A-K communication of TEL is normal 
* In case of call from COLI 
(I ) Does RLI operate by the call data of TEL? 
(no dial tone can be heared) 
t Does RLI operates by 
Does it output Q-J,! 
status? (Q status? 
(2) Does R L3 and 5 operates by call dialing data of TEL ? 
20 
21 
IC4 
22 
23 
1 1 1 
RL3 RL4 RL5 RL6 
Qi3 IC24 I   
0 
I t 
1 
Does R L5 operates during the dialing? 
Does it output 0 status? 
Does R L3 function ON 
and OFF with dial pulse? 
For example: In case of press the dial key 3 
wI” f Does it output 5V? 
12 3 
- 29-  
						

							Service Check Point-9 
Can not call CO originate (DTMF) . . In case of the A-K communication of TEL is normal 
* In case of call from COLI 
(I) 
(2) 
Does RLI operates by the call data of TEL? 
(no dial tone can be heared) 
t Does R Ll operates by 
Does it output 
@ status? 0 status? 
Does RL5 operates by the call dial data of TEL? 
I 7 I 
(confirmation tone is too louder) 
Does it output 
@ status? 
(3) Does it output the DTMF dial signal? 013 IC24 
h--G - 0  IC24@ 
Does it operates when the 
DTMF dial sending? 
Does it output @ status? 
r-7 ---_) (When dialled 1) 
I 
I ’ Does it output the DTMF signal? 
I I ICI2 f Does it output the .  10 I ’ ] 3 / DTMF signal? ( 
19 COLi 1 4 COL2 
20 1 5 
I COL3 COL 1 
21 
IC5 22 
i4 ROWi 
I3 ROW2 
23 I2 ROW3 
24 
’ ’ ROW4 
Does it output 0 status 
on COLI and ROWI? 
14 
I IC4 I 15 
I 
t 
1 
Does it output 0 
Does it output @ Explanation of IC2 
COLi COL2 cOL3 
status when the DTMF status when the DTMF 
signal is sending? 
signal is sending? 
- 30 - ROW1 
ROW2 
ROW3 
ROW4 COL and ROW of 
IC2 is output the 
DTMF signal 
when input @ status  
						

							Service Check Point-10 
Can not dial with specified TEL at power failure 
(I 1 Does it supply the battery voltage? 
R4 
2 
ZD 
,,. Battery side with:5  i 
t I 
I R48 
I, 
RL9 
DlO 
ib 
0 
CC52 
Battery 
I-= 
* Ia 
2 
1) Does Qll turn to OFF when the AC power is failed? 
2) Does IC8 (pin No. 2) return to @ status by 011 is OFF? 
3) Does Q9 turn to ON? 
4) Does R L9 operates?  
						

							‘. 
_ . . 
. . . 
ORDER NO. LCD850014 Sl 
Technical Inform&ion 
Easa-Phone;” 
Key Telephone System VA-208 
VA-208 10 
A SUPPLEMENT V 
W INTRODUCTION 
This manual is for the key telephone with built-in speakerphone and optional equipments of the key telephone system VA-208. 
Panasonic. 
Panasonic Company 
Panasonic Hawaii, Inc. 
Division of Matsushita Electric Corporation of America 91.238 Kauh St., Ewa Bearh, Hor~olulu. Hawaii 96808-0774 
One Panasonic Way. Secaucus. New Jersey 07094  
						

							HEXPLANATION OF CIRCUIT OPERATION 
1. Key telephone with built in speakerphone 
1.1 Conversation 
Handset is connected to T and R line when HSI is ON. 
R38 
(I) 
(2) 
R2f3 
DE I 
L 1 Incoming 
Signal R33 
Receiving circuit 
The received voice signal is connected to the receiver via the following path. 
T, R terminal + HSI (ON) + DBI (Rectifier) + Sink circuit (Provided to maintain conversation quality by a 
constant current supply for various distance conditions to the Central Office Exchange) -+ Tl -+ Q4 (Receiver 
amp.) -+ R (Receiver). 
Transmitting circuit 
The send signal is connected to T and R terminal via the following path. 
MIC + 06 (Transmitter amp.) 
+Tl + DBI + HSI (ON) +T, R terminal 
NOTE: When the send voice level is over the specified level, 07 to 09 (The receiver mute circuit) suppresses 
the side tone by Q9 (ON). 
-3-  
						

							1.2 Functional operation circuit 
HSI 
Speakerphone Unit 
HS3 1 
+5v 
R42 
;:I RI6 
017 
P60 
P61 
P52 
P62 
P63 
1 P93 
P90 
P53 
P91 
I 
P20 
PB3 
P82 
P81 
1 PBO) R43 
R36 
CN5 
(I) COL lamp flashing during CO line use (eg. COL 1). 
When the COL incoming call lamp signal arrives to the TEL from the KSU, pin (32) of ICI outputs the control 
signal (0.5 sec. @ 
, 0.125 sec. @ 00 and 1.5 sec. @ ). The lamp control signal turns ON the COL lamp 
when the signal becomes 0 and turns OFF the COL lamp when the signal becomes 0. This is the reason the 
COL lamp flashes. 
(2) Sounding of COL incoming call tone. 
When the COL incoming call tone sounding signal is inputto the TEL from the KSU, pin (37) of ICI becomes 
@ level. Then the @ level-signal is sent to pin (5) of IC5 via D5, and turns IC5 (ON). 
From the above process, the COL incoming call tone which is sent from T and R terminal, is sent out from pin 
(3) of IC5 to pin (4) the incoming call tone is then sent to IC6 via C15, and the input signal is amplified by IC6 
which then emits the call tone from the SP. 
-4-  
						

							(3) Intercom call tone sounds and intercom voice call. 
When the intercom call sounding signal and voice call signal is sent to the TEL from the KSU, pin (36) of ICI 
becomes @ level. The @ level-signal is sent to pin (5) of IC5 via D4 and turns IC5 to ON. The following opera- 
tion is the same as in clause 2.2. 
(4) Interrupt tone control and interrupt tone output. 
The interrupt tone control signal is sent to the TEL from the KSU, pin (23) of ICI becomes @ level, then the 
receiving SW at busy IC5 (pin 1, 2) is turned to ON at the @ level on IC5 (Analog switch). 
The interrupt tone is sent to the speaker by the following path. 
ICI (27) -+ Q5 (Amplify) --f IC5 (1) 
+ ICI (2) -+ IC6 (Amp.) + Speaker. 
(5) Key-in tone control and Key-in tone output. 
1) Handset output 
l When the handset is OFF-hook, the off-hook detection signal is sent to the KSU with input the @ on pin 
(16) of ICI by HS3. 
When the dial key is pressed pin (22) of ICI outputs @ -+ the @ level on pin (12) of lC5 then turns the 
Key-in tone switch IC5 (IO, 11) to ON. 
l The Key-in tone output is outputted from the receiver when the dial key is pressed by the following path. 
ICI (27) -+Q5 (Amp.) -f IC5 (11) --f IC5 (10) +C13+T2+ Receiver 
2) Speaker output 
l When the dial key is pressed, the @ level-signal is outputted from pin (22) of lCl,which turns the Key-in 
tone switch IC5 (10,ll) to ON with the @ level on pin (12) of IC5. 
0 Key-in tone is output from SP when the dial key is pressed by the following path. 
Q5 (Amp.) + IC5 (11) + IC5 (10) + R37 + R34 + IC5 (9) -+ IC5 (8) -+ IC6 (Amp.) -+ 
SP 
1.3 Power supply for TEL 
To speakerphone unit 
Cl-II Ql 
HO * 
0 
+ 
LL 
c3 
Jr’ Cl =z 
+ 3 Dl 
D18 ‘r IZCE + 
ZZ C28 
IZ c4 
+12V DC is supplied from the KSU to the TEL. Supplied voltage is converted to +7V and +5V by the voltage 
regulator circuit and converted voltages are used for the power source of the TEL. 
-5-  
						

							ORDER NO. LCD850014 Sl 
Fl 
’ Technical Information 
1 Easa-Phone;” 
Key Telephone System VA-208 
A SUPPLEMENT V 
VA-208 IO VA-20820 
H INTRODUCTION 
This manual is for the key telephone with built-in speakerphone and optional equipments of the key telephone system VA-208. 
Panasonic. 
Panasonic Company 
Panasonic Hawaii, Inc. 
Divismn of Matsushita Electric Corporation qf America 91-238 Kauh St,, Ewa Beach, Hor~olulu. Hawaii 96808.0774 
One Panasonic Wav. Secaucus. New Jersey 07094  
						

							CONTENTS 
BLOCKDIAGRAM ............................. . ................................... 1 
1. 
Key telephone with built in speakerphone (VA-20821) ...................................... 1 
2. Doorphone Adaptor (VA-20860) 
..................................................... 2 
3. Extension Card (VA-20840) 
........................................................ 2 
4. Extension Card (VA-20841) 
........................................................ 2 
EXPLANATION OF CIRCUIT OPERATION .............................................. 3 
1. Key telephone with built in speakerphone (VA-20821). ...................................... 3 
1.1 Conversation 
............................................................... 3 
1.2 Functional Operation Circuit 
.................................................... 4 
1.3 Power Supply for TEL. 
........................................................ 5 
1.4 A-K Communication .......................................................... 6 
1.5 Speach Path Change Circuit 
..................................................... 6 
1.6 Transmitting Circuit (Speakerphone) 
............................................... 7 
1.7 Receiving Circuit (Speakerphone) 
................................................. 8 
1.8 Send Voice Signal Detecting Circuit ................................................ 9 
1.9 Receive Voice Signal Detecting Circuit .............................................. 9 
1.10 VoiceSwitch ............................................................. ..I 0 
2. Extension Card (VA-20840/VA-20841). 
............................................... .I1 
2.1 Data Communication between Key TEL and KSU ...................................... .I1 
2.2 Data Communication between SLT (Single Line Telephone) and KSU. 
........................ .I2 
2.3 Incoming Tone Oscillation Circuit (VA-20841) ......................................... 13 
2.4 DTMF Signal Receiving Circuit (VA-20841). 
......................................... .I3 
3. Doorphone adaptor (VA-20860) .................................................... .I4 
3.1 Call Detecting Circuit ........................................................ .I4 
3.2 Call Tone Oscillation Circuit .................................................... .I4 
3.3 Doorphone Power Control Circuit ................................................ .I5 
3.4 Doorphone Conversation Circuit ................................................. .I6 
4. Doorphone Unit (VA-20861). ...................................................... .I7 
4.1 CallCircuit .............................................................. ..I 7 
4.2 Conversation.. ........................................................... ..I 7 
5. Extension bell (VA-20863) 
. . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .I8 
‘. 
TROUBLE SHOOTING GUIDE.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19