Karel MS48 - System Power Requirements; SPS48 Power Supply Module

Karel MS48 Installation & Maintenance Guide
Edition 3.2
8
I.2. POWER TO THE SYSTEM
MS48 system receives 220 VAC from the mains. Inside the fuse slot next to the
system ON/OFF switch, there exists a F-type fuse of 1 A / 250 VAC for the first step
protection.
The system can operate for the mains input of 180 - 260 VAC 50/60 Hz. The
PWT48 Power Transformer generates 2x15 VAC from the mains voltage, which is
processed by the SPS48 Power Supply Module.
The PWT48 Power Transformer is located inside a metal cage at the up left corner
of the CBN48 cabinet, together with the RNT48 Ring Transformer which generates
64 Vrms ring signal.
I.2.A. SPS48 POWER SUPPLY MODULE
SPS48 Power Supply Module is simply a card that resides below the metal cage
surrounding the RNT48 and PWT48 transformers.
SPS48 is a Switched Mode Power Supply (SMPS). Receiving 2x15 VAC from the
PWT48 Power Transformer, SPS48 generates +5 VDC, +12 VDC and -24 VDC for
the system operation, for the accessories and for the RNT48 Ring Transformer.
The output of the RNT48 transformer is the 64Vrms ring signal, which is transferred
to the MB48 motherboard directly.
SPS48 also has connectors for KY16 Mini Printer and OP48(-H) Consoles /
LT48(-H) Feature Phones / PG100 Local Pager / IA12 ISDN Adaptor. The Busy and
Data signals on these connectors are not processed by SPS48, they are just
received from the MB48 motherboard so as to be transmitted to the accessories.
See the following figure for the location of the connectors on SPS48.
Figure A-6
The pin-out of the connectors on SPS48 module are illustrated in the following
table: