305 BROADCAST LLC ETG100010 Manual Do Utilizador

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threshold that can be exceeded for short periods (up to 1 minute each time).
If this condition occurs, it is enabled “PSU current derating” (“013” alarm and possibly 
“014”) and ALC management algorithm to normal operating condition is replaced by 
another in which the VDS and Bias control is given by power setting and, with even 
higher priority, by the current supplied from power supply.
The condition of current derating is turned off when the power supplied back to the va-
lue set by the user and if the maximum current supplied from power supply is less than 
or equal to the maximum allowable value for continuous operation.
Thermal management on power supply (Lifextender ®) 
The algorithm of power supply management, function of temperature, is the same as 
that in the RF group, and is connected logically “OR” to it.
The first level of Derating (which acts directly on the output power) is activated when 
the power supply temperature exceeds 75 ° C, while the second level is activated if, 
with the first ineffective, the temperature is not stable below this value. In this second 
case the output power is brought below the - 3 dB, with the same procedure already 
described in RF section. On the display the activation of this mechanism is manifested 
by the “010” alarm, and possibly “016”.
Fault management on RF modules (Lifextender ®) 
It makes the maximum output power management depending on the number of RF 
amplifier modules being properly operated.
If one or more MOSFETs are considered failed (this happens when the current consum-
ption is less than 10% of the average), RF output power is reduced to the expected 
value in the presence of failure experienced. The failure case histories and maximum 
power achievable are described in a complex table obtained through experimentation, 
and are designed to stop MOSFETs failure, that are still operating, by avoiding that are 
overly stressed by the mechanism of ALC (which would call these to supply the power 
output missing).
To avoid an unnecessarily large number of alert SMS, during this stage are not sent: any 
alert SMS, if validated, will be sent only after the output power adaptation procedure, 
according to the parameters table, and only if -3dB condition is verified.
On the display the activation of this mechanism is manifested by the “008” and “009” 
alarm.
Cooling Management on fans group (Lifextender ®) 
The fan speed is adjusted, depending on the actual cooling needs, from a minimum of 
60% to a maximum of 120% (these values may differ by different models of fan used). 
The cooling need is estimated on the basis of accurate temperature measurements 
that are made on RF MOSFETs and on power supply. The Cooling Management aims to 
extend the lifespan of the fans, to minimize the amount of dust that can be carried by 
the airflow, and to guarantee a safe operation of the apparatus, even under extreme 
conditions of temperature.
Without Lifextender the fans operate at 100%.
2.3.2 Hardware protections
The hardware protection system includes:
•  fast electronic and fuse protection on power supplies;
•  fast electronic protection on fans power supply ;
•  fast protection against excessive reflected power (ROS/VSWR), caused by a strong 
mismatch of the load. This protection occurs when the value of reflected power 
exceeds 10% of the direct power.
Product description