Panasonic Easa-Phone VA-208 Installation Manual page 128

(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-