TEX30/50/100/150/300LCD
ELETTRONICA
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User Manual
Rev. 1.0 - 29/11/12
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Control of the power level in output, depending on the setting
•
Reduction of the power supplied when in presence of high-level reflected
power
•
Measures of the forward and reflected power by means of directional
couplers
•
Measures of the current absorbed by the power amplifier
•
Measures of the temperature
•
Low-pass filtering of the RF signal in output
This board also features an RF sampling of approximately -30dB RF with respect
to the output, which is available on a BNC connector below the transmitter output
connector. This sample is is useful for verifying the characteristics of the carrier,
but not for verifying those of the upper harmonics.
7.2.3 Control Board
The main function of this board is to check and correct the MOSFET polarization
voltage of the RF amplifier section.
It also provides the measurement of the absorbed current and contains a circuit
for signaling power supply unit faults.
If no alarms are present, the voltage is adjusted only depending on the set output
power, with a feedback mechanism based on the reading of the power really
delivered (AGC).
The voltage is also affected by other factors, such as:
•
Excess of reflected power.
•
External AGC signals (Ext. AGC FWD, Ext. AGC RFL).
•
Excess of temperature.
•
Excess of absorbed current from the RF module.
7.3 TEX50/100/150LCD Different Parts
7.3.1 Power Supply
The
TEX50/100/150LCD
power supply unit is a switching-type unit whose +28 V
main output powers the machineÌs RF amplifier. The power supply also features
stabilizers for generating cont5 V, -15V, +8V, +18 V and -18 V voltages
for powering the other device circuits. The power supply unit is also connected to
24 V auxiliary continuous voltage inputs used to automatically buffer the mains
power cutoff.
