4-20
888-2595-001
12/20/11
WARNING: Disconnect primary power prior to servicing.
Section 4 Theory of Operation
ZX Series
Since a LOW_GAIN_FAULT will always be present when the transmitter is off
(because the power is indeed low i.e zero ), the red segments will always glow when the
transmitter is switched off.
LEDs DS4 through DS12 provide signalization of a variety of fault conditions. These
LEDs are located on the reverse side of the controller board and may be accessed by
opening the front door of the amplifier chassis. This is consistent with a maintenance
philosophy that dictates that the front panel LEDs DS1, DS2, DS3 signal the summary
status (green = OK, yellow/red = not OK). If a not OK condition is indicated, the
technician opens the front door to inspect the unit and determine the origin of the
problem.
4.12.6 Load Temperature Fault Sensor
(page 6) Latched comparator U27A toggles from a low (non-fault) to a high (fault) state
whenever the MAX_LOAD_TEMP sample arriving at pin 3 exceeds the +2V reference
from voltage divider R98-R105 at pin 2. Positive feedback resistor R99 ensures that
circuit remains latched with a +3.5V high output even after the high load temperature
condition is resolved. A +5V pulse from the ON/OFF/RESET line via CR26 causes the
output to toggle back to a low, non-fault state. A MAX_LOAD_TEMP sample of 2V
corresponds to the maximum allowable load temperature of 125 degrees centigrade.
4.12.7 Ambient Temperature Sensor
Thermistor RT1 senses the ambient temperature and controls the gain of amplifier
U27B. The temperature variable gain is applied to a 0.1V reference developed by
voltage divider R96-R2. The result is a temperature sample based on a natural
logarithmic scale. The resulting AMB_TEMP sample voltage is interpreted by the
optional web remote card to provide a display of the ambient temperature in degrees.
4.12.8 Drain Voltage Adjust
Voltage divider R36-R122-R119 provides a means to set the V_PROG voltage sent to
the PS modules to determine their output voltage.
4.13 System Metering Assembly
Consult drawing 801-0203-731
Summary of Contents for ZX10
Page 2: ...ii 888 2595 001 12 20 11 WARNING Disconnect primary power prior to servicing ...
Page 4: ...iv 888 2595 001 12 20 11 WARNING Disconnect primary power prior to servicing ...
Page 6: ...MRH 2 888 2595 001 12 20 11 WARNING Disconnect primary power prior to servicing ...
Page 8: ...viii 888 2595 001 12 20 11 WARNING Disconnect primary power prior to servicing ...
Page 9: ...12 20 11 888 2595 001 ix WARNING Disconnect primary power prior to servicing ...
Page 10: ...x 888 2595 001 12 20 11 WARNING Disconnect primary power prior to servicing ...
Page 14: ...xiv 888 2595 001 12 20 11 WARNING Disconnect primary power prior to servicing ...
Page 18: ...Table of Contents Continued 4 ...
