Tadiran Telecom Coral IPx 800 Series Installation Procedure And Hardware Reference Manual page 337

48VDC Output Power
–
The PS19 DC-D also filters and limits the –48VDC input to feed the peripheral card
slots.
Ripple and Noise
Filtering circuitry minimizes ripple and noise on the –48VDC feed to the peripheral
cards. The filtering circuitry produces an output voltage approximately 1.5V to 2V
lower than the input voltage to the PS19 DC-D.
Hot Swap Circuitry (Redundant Configuration)
The PS19 DC-D contains Hot Swap circuitry for redundancy purposes, so that if one
among two connected PS19 DC-D units fails, the second unit may "take over" the
power supply production.
Monitoring Circuitry
All outputs, with the exception of the –48VDC output, are regulated.
Voltage and current level monitoring circuitry check each output of the PS19 DC-D
(including message and ring generator currents), and produce an alarm signal to the
Coral system main processor in the event of malfunction.
Monitoring circuitry verifies that each voltage output (with the exception of the
–48VDC output) is within specification. If any voltage deviates from specification, the
monitoring circuitry produces an alarm signal to the Coral system processor, causing
the red Alarm indicator to light. Note that the green Power indicator of a PS19 DC-D
remains lit at the same time as the red Alarm indicator.
If the voltage input drops below 36.5±1VDC the unit shuts down and returns to power
only when the voltage raises above 38.5±1VDC again. Additionally, if the voltage is
greater than 62±0.5VDC, then the unit shuts down until the input voltage drops below
58±0.5VDC.
7-23
Power Supplies