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SIRIO 2000T
SIRIO 2000T
SIRIO 2000T
SIRIO 2000T
SIRIO 2000T
Electronic Broadcast Equipment
THE MAIN POWER SUPPLY REGULATOR
This module gives an efficient regulation of the raw dc input, 140V
±
15% to the nominal lower one
of 48V needed by the RF output power modules. Being the efficiency very high, only a little heat is
produced in the regulation process. The current capability of the regulator is higher than requested,
approacheing some 70A @ 48V.
A control I/O connector on an upper daughter board, allows a remote control of the regulator by the
transmitter controller, i.e. output on/stand-by, current and voltage monitoring, status prompting and alert.
The regulated voltage is dynamically varied by the ALC control with the output power, to maintain
high efficiency at reduced power levels, proportionally decreasing the generated heat amount. The voltage
varies in the range of 30 to 48V, the higher one being measurable only when the transmitter is set at the
maximum output power.
A fast 80A semiconductor-grade protection fuse is screwed on the board: it may be fused by the
crowbar protection in case of switching transistor damage. If this happens a first attempt to replace the
fuse may be accomplished, after having verified the integrity of the power transistors. Usually something
is broken so causing the fuse blow-up.
Reparation of this module in the field is very difficult if any component other than the fuse and/or a
power transistor failed. It is strongly suggested to replace the module with a new one, and to send back
the damaged one to the factory for inspection and a possible repair.
