Tadiran Telecom Coral IPx Office, Руководство по установке и аппаратным средствам, Страница: 250 / 510

7-16
Power Supply Coral IPx Office Installation Manual
PS
Office DC Power Su
pply Unit
7
0
Figure 7-9 presents a block diagram of the PS Office DC power supply.
Power Input Section
The DC input includes a passive filter, inrush current, and a power switch. The DC
input is protected against reverse polarity.
DC Output Power
The DC to DC converters convert the –48VDC power to the following outputs:
„
+5VDC
„
+3.3VDC
„
-48VDC
-48VDC Output Power
The PS Office DC 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 that is approximately 0.5V to
1.0V lower than the input voltage -VIN to the PS Office DC.
If the voltage input is less than –38
±0.5
VDC or greater than –58
±0.5
VDC, the power
supply shuts down. The power supply will turn on when the voltage is greater than
–58
±0.5
VDC or less than –45
±0.5
VDC.
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2 Circuit Description