This document describes a monitoring, protection, and control module for a radar transmitter. The module monitors key transmitter parameters, protects the system by triggering faults if parameters exceed thresholds, and controls the transmitter's on/off sequencing. It uses comparators to detect parameter faults, a microcontroller for control and interfacing, an ADC to convert analog signals, and an LCD for output display. The design aims to safely monitor and protect the expensive transmitter components.

1. MONITORING, PROTECTION &
CONTROL MODULE FOR A RADAR
TRANSMITTER
BY
ABHISHEK SUTRAVE (1RN05EC004)
AMOGHA VARSHA B.S (1RN05EC012)
KEERTHI D.H (1RN05EC041)

2. INTRODUCTION
• A TWT based Radar Transmitter would
have three major sub-systems
1)High Voltage High Power supply
2)Grid Modulator or Pulser
3)Monitoring, Protection & Control unit
(MPC)
• Our project focuses on a part of the MPC
unit of the entire system.

3. TWT transmitter
kollector, heizung, eingang, ausgang
collector, heating, input, output

5. Need/OBJECTIVE
1) The circuits which generally operate from 5V to 15V, are
under heavy EMI and high current transients similar to lighting
environment.
2) For monitoring the floating parameters, samples of values are
to be brought to the ground reference.
3) The ground referenced control unit is conceived in two parts.
• First a dedicated set of latching voltage comparators capture
any parameters crossing the threshold limit. The faults are
categorized as A,B,C & D based on the severity. Appropriate
action is initiated to protect the transmitting tube.
• Secondly, a microcontroller carries out the switching ON/OFF
sequencing, A/D conversion of analog voltage and current
values and status bit reading.
7) The outputs from the microcontroller are displayed through a 2
line 16 character LCD panel.

6. DESIGN GOALS
• To monitor the transmitter parameters which
cause TYPE A fault.
• To sequence the safe switching ON and
switching OFF.
• To protect the highly expensive TWT and
various other electronic devices from damage
in the event of erroneous conditions.
• To capture and display the parameters, error
messages in the LCD.

7. How design will be made
• A set of latching comparators to capture
and register the occurrence of error.
• A micro controller to do the sequencing
ON/OFF, carry out the A/D conversion of
analog parameters, and display the states
on an LCD display panel.
• Proper setting of threshold limits to
obtain noise immunity.

8. BDO OF THE ENTIRE SYSTEM

9. HARDWARE DESCRIPTION
Hardware part consists of
• Monitoring Unit
 Comparator module
• Control and Display Unit
Microcontroller, ADC, LCD

10. Comparator Card Circuit

11. • COMPARATOR CARD
 Scaled down voltage and current values of the
transmitter parameter, are taken as I/P to the
comparator card.
 In our project we are considering only the parameters
causing TYPE A fault.
 Its basic function is to compare the I/P with the
reference value and make the corresponding LED
glow upon threshold exceed.
 OPAMP’s LM324 is used for Amplification/Gain,
LM139 as a Voltage Comparator and ULN2001A as
a driver.

13. • Microcontroller:
 P89V51RD2 is a Microcontroller from Philips. The
microcontroller is used to interact between various
other components.
 It is programmed to accept the data from the ADC
and the comparator card, compare the values received
with the default threshold values, and output the
result to LCD, and accordingly switch on the buzzer
and the relay switch.
 The entire operation of the circuit is controlled by the
software embedded in the microcontroller.

14. P89V51RD2 FEATURES
• 80C51 Central Processing Unit
• 5 V Operating voltage from 0 to 40 MHz
• 64 kB of on-chip Flash program memory with ISP
(In-System Programming) and
• SPI (Serial Peripheral Interface) and enhanced
UART
• Four 8-bit I/O ports with three high-current Port
1 pins (16 mA each)
• Three 16-bit timers/counters
• Programmable Watchdog timer (WDT)

15. • Analog to digital Converter:
 The ADC 0809 is an analog to digital converter. It
accepts the analog I/P values from the comparator
card and gives an 8 bit binary O/P value, which is
given to the microcontroller.
 It is is a 8-channel multiplexer which uses successive
approximation as the conversion technique.
 For the scale of 0-5 V, the step size is 19.53mV for
full scale output. The input analog voltage is divided
by the step size to give a digital output.

16. FEATURES OF ADC
• Easy interface to all microcontrollers.
• No zero or full-scale adjust required.
• 8-channel multiplexer with address logic.
• 0V to 5V input range with single 5V
power supply.
• 28-pin molded chip carrier package.

17. LCD:
The 16*2 LCD is used to display real-time
comparator card I/P values and occasionally
the error values if present.

18. Serial Port Interface: RS 232

19. RELAY:
• A relay is an electrical switch that opens and closes
under the control of another electrical circuit.
• The switch is operated by an electromagnet to open or
close one or many sets of contacts.
• Since a relay is able to control an output circuit of
higher power than the input circuit, it can be
considered to be, in a broad sense, a form of an
electrical amplifier.
• Different switching conditions
• 1.Normally-Open (NO): contacts connect the circuit
when the relay is activated; the circuit is disconnected
when the relay is inactive. It is also called a FORM A
contact or “make” contact.

21. 2.Normally - Closed (NC): contacts disconnect the circuit
when the relay is activated ; the circuit is connected when
relay is inactive. It is also called “Form B” contact or” break”
contact
3.Change-over or double-throw: contacts control two
circuits; one normally open contact and one normally closed
contact with a common terminal. It is also called a Form C
“transfer “ contact.
Sugar cube Relay

22. PROGRAMMING
FLOW CHART

23. FLOW CHART representing the
working of the system

24. FLOW CHART FOR LCD INTIALIZATION

26. FLOW CHART FOR ADC INTIALIZATION

27. FLOW CHART FOR ISR

28. SOFTWARE OVERVIEW
In our project, the assembly code is
compiled, built and converted to
hexadecimal code by the KEIL MICRO
VISION V.2 software.
The hex file is then fused/burnt onto the
microcontroller using FLASH MAGIC
software through the RS232 pin of the
MAX232 driver.

31. LIMITATONS
Only 4 values can be Monitored,
Protected & Controlled.
All the ports of the microcontroller
are used and hence other I/P or O/P
bits cannot be used.

32. ENHANCEMENTS
In this project we are checking only 4 I/P
values of TYPE A faults, where as there are 28
values in all which are categorized into faults
A,B & C.
 Clearly there is a large scope for increase in
the I/P values to be Monitored, Protected &
Controlled.
A larger LCD can be used to display the values
required simultaneously.
A Programmable peripheral interface(8255)
can be used to enhance the ports of 8051.

33. APPLICATION
 MPC of various Large Scale
Systems
 Surveillance system
 Guidance/fire control
system
 Air traffic Control system
 Airborne Interception
system
 Missile Control systems
 TV & Radio Broadcasting
system
 Weather Station

35. CONCLUSION
• The Protection of any large scale
machines would be of utmost
importance for any company.
• With a Protection module as simple and
less expensive as this, any company can
implement this on their system with a
fewer modifications for extended ability.