Rohde & Schwarz SR8000 Series, System Manual

Page: 45 / 199

Chapter 2 Design and Function
5300.9677.72 - 2.24 - EN-4
2.1.4 Power Supply Fault (R&S SR8130)
The transmitter has three power supply units. The exciter board and the mainboard are sup-
plied with power from an auxiliary power supply unit with current-limited output. All lines car-
rying AC supply voltage and high current are covered to prevent touching (double
insulation, sheathed coshrink-on sleeve).
If primary side components fail, the primary fuse trips. Transfer of primary side overcurrent
to the secondary side is prevented by the potential isolation of the power supplies. The sup-
ply of power to the exciter board and mainboard is safeguarded by means of the output-
current limitation of the auxiliary power supply unit.
In view of the power required from the current supply, the current available at the auxiliary
power supply output can be as high as 10 A and as high as 70 A at the output from the am-
plifier power supplies.
Fault Protection mechanism Function
Damage between line filter
and power supply unit Protected by primary fuses Primary fuse trips.
Damage to power supply
unit Protected by primary fuses Primary fuse trips.
Damage between amplifier
power supply unit and ampli-
fier board Current limited by amplifier power sup-
ply unit Current limitation
Overload by exciter board/
mainboard Current limited by auxiliary power sup-
ply unit Current limitation
Fault Protection mechanism Function
Damage between AC supply
input and power supply unit Protected by primary fuse Primary fuse trips.
Damage to power supply
unit Protected by primary fuse Primary fuse trips.
Damage between amplifier
power supplies and amplifier
board Current limited by amplifier power sup-
plies Current limited
Overload via exciter board/
mainboard Current limited by auxiliary power sup-
ply unit Current limited