PS-31
System Power Supply
The Model PS-31 supplies 32 volts of regulated DC power to each of three intercom channels. It has short circuit and thermal
overload protection, with automatic recovery when the fault is removed.
Program Input
There is a program input connector on the rear panel. A
channel assign switch on the front panel assigns the pro-
gram to any of the three channels. A level control adjusts the
program level to the intercom channel.
Status Indicators
There is an audible alarm and a red fault indicator for current
overload indication on any of the three channels. An audible
alert switch on the front panel turns the alarm on or off, but
the fault indicator will continue to ash during current over-
load conditions. There is also a green status indicator for
each channel. Each of these indicators will remain lit during
normal operation, but will turn off during a channel current
overload condition. Output current is automatically reduced
during an overload and normal operation is restored when
the overload is removed.
Input Power
The PS-31 is available in two versions: one for 115 VAC op-
eration and one for 230 VAC operation. A power on/off switch
is provided on the front panel.
Intercom Channel Connections
Intercom channels are connected to the rear panel of the
PS-31. A variety of connector pin-outs is provided to accom-
modate individual system requirements.
Impedance Selection
The PS-31 provides the required channel terminating imped-
ance for each channel. A 200/400 Ω impedance select switch
for each channel is located on the rear panel. These switch-
es are set to 200 Ω for normal operation. The 400 Ω setting
permits two PS-31’s to be coupled to double the DC capacity
of the system.
Features
Line Drawing