GAI-Tronics 12600-002 Line Current Boost Circuit Assemblies - Manual (Page 2)

Pub. 42004-433C
Model 12600-002 and 12600-40x Line Current Boost Circuit Assemblies Page: 2 of 5
f:\standard ioms - current release\42004 instr. manuals\42004-433c.doc
07/11
When the dc voltage between tip and ring falls below 15 V dc, indicating an off-hook condition on the
line, the LCBC automatically adds 30 mA current to the available line current. If the PBX provides 20
mA line current, the LCBC adds an additional line current of 30 mA for a total of 50 mA available to
drive speakers and other devices.
When the device connected to the line is placed on-hook (dc line voltage greater than 20 V), the LCBC
automatically disconnects the 30 mA supplemental line current. The LCBC is transparent to incoming
ring signals allowing operation on a 2-wire bridged ringing configuration.
CHANNEL 1 CHANNEL 2 CHANNEL 3 CHANNEL 4 CHANNEL 5 CHANNEL 6 CHANNEL 7 CHANNEL 8
Figure 2. Front Views of Model 12600-402/404 8-Channel LCBC Assemblies
N OTE : Model 12600-401/403 4-Channel LCBC Assemblies contain a blank panel on the right side.
48 VDC +/-20%
Figure 3. Rear Views of Models 12600-401/402 DC-Powered (top) and Models 12600-403/404
AC-Powered LCBC (bottom) Assemblies
PABX Interface Requirements
Minimum loop current: 8 mA dc (LCBC disconnected)
Maximum recommended loop current: 40 mA dc (LCBC disconnected)
Ringer requirements: Type B ringer