The document describes the modification of the RN10 voltage regulator and development of a portable testing jig for the BMP2 tank. The RN10 regulator is replaced with an L4970A IC which has advantages like high efficiency, compact size, and easy replacement. A portable testing jig is also developed to test components of the control unit without dismantling the entire tank. It can check parameters like converter output, stabilization card voltages, gyro and compensator signals, and elevation/traverse outputs.

1. ARMY INSTITUTE OF TECHNOLOGY PUNE
Department of Electronics & Telecommunication Engineering
Vocational Training
512 Army Base Workshop
Presented By:
Ajeet Pandey
REG NO: 14494
ROLL NO: 1308
PROJECT: Modification of RN10 Voltage regulator of BMP2 TANK &
Portable Testing Jig for BMP2 TANK
Guided By:
Col. R K DESHMUKH
DGM ETD CELL

2. INTRODUCTION
• Three main requirements are Mobility, Firing Power and Protection.
• In BMP-2, capacity for 3 people. Commander, Driver and Gunner +7 Crew Member.
• Gunner is responsible for laying the gun.
• Driver drives the tank, and also serves as day to day mechanic.
• The commander is responsible for commanding the tank. The commander is provided with all round vision devices rather than the limited
ones of the driver and gunner.
• The voltage regulator RN 10 is designed for functioning in the vehicle electrical equipment's jointly with the generator,
storage batteries, , reverse current relay DMR – 400T and to automatically maintain the generator voltage with in 26.5 to
28.5 volts at variation of the generator armature rotation speed and variation of the generator load.
• It is fitted above the power distribution board in troops compartment. The generator voltage is regulated by the voltage
regulator through the control transistor included in the circuit of the generator field winding as a variable resistance.

3. • The voltage regulator RN 10 is designed for functioning in the vehicle electrical equipment's jointly with the generator, storage batteries, , reverse current relay
DMR – 400T and to automatically maintain the generator voltage with in 26.5 to 28.5 volts at variation of the generator armature rotation speed and variation of the
generator load.
• It is fitted above the power distribution board in troops compartment. The generator voltage is regulated by the voltage regulator through the control transistor
included in the circuit of the generator field winding as a variable resistance.
The basic elements of regulator is:-
1.Measuring device
2.Regulating device
3. Feedback circuit
4.Circuit breaker element
IC -L4970A
DESCRIPTION:-
• The L4970A is a stepdown monolithic power switching regulator delivering 10A at a voltage variable from 5.1 to 40V
• This technology allows the integration of isolated vertical DMOS power transistors plus mixed CMOS/Bipolar transistors.
Voltage regulator RN-10:-

4. L4970A BLOCK DIAGRAM
1. MILITARY STANDARDS
2. EASILY AVAILABLE
3. INTERNAL CURRENT LIMITING (SHORT CIRCUIT)
4. THERMAL SHUTDOWN
5. COMPACT
6. EASILY REPLACIABLE
7. Very high efficiency
8. LESS COMPLEX
ADVANTAGES OF USING L4970A IC

8. Portable Testing Jig
• We can Test Control Unit’s component with the help of inbuilt DMM present on Portable Test Jig without
Dismantle whole Tank.
• Also called Built-in testing Equipment (BITE)
• A built-in test equipment (BITE) is a mechanism that permits a machine to test itself.
• The main purpose of BITE is to reduce the complexity, and thereby decrease the cost and reduce reliance
upon test equipment

9. Working of Testing Jig
Parameters for testing
• COVERTOR OUTPUT
• STABLIZE CARD FOR +/- 15V
• INPUT SIGNAL OF INTEGRATOR AND IT OUTPOT.
• SUMMING AMPLIFIER OUTPUT.
• TIME DELAY CIRCUIT.
W-2 and W-6 female sockets W4 MALE CONNECTOR

10. Components of Stabilization System
K-1 M Box
• Heart of stabilization system.
• It is also called the First Distribution Box.
• K1M box is the most important component of stabilization system.
• It contains all the relays, microcontrollers, ICs of the system, and manages all the
input and output signals.
• K1M Box is responsible for all the inputs and outputs. It receives input signal if
Commander presses button to load ammunition, or driver rotates the turret, etc.
and performs the desired action.
• To rotate the turret, K1M Box sends electrical signal to PWDM and it converts the
electrical signal to corresponding hydraulic force.
• High Torque Motor uses the signal sent by PWDM to rotate the turret
• Similar process is followed in the elevation side which is responsible for the
vertical movement of Gun.
• The Elevation Booster receives the electrical signal and converts it to
corresponding hydraulic force.
• The Actuating Cylinder expands or retracts and varies the elevation of gun.
• Battery supplies 24V DC supply to Convertor which converts it to 40V AC supply at
500 hz frequency, and supplies it to K1M box.

12. Components of Stabilization System
Elevation Unit
• This unit is responsible for the vertical movement of the gun.
• It comprises of Elevation Booster (like PWDM in Traverse unit), Actuating
Cylinder (elevates the gun) and Gun.
Traverse Unit
• This part of Stabilization System rotates the Turret through 360o.
• It consists of PWDM (Pump with Dry Motor), High Torque Motor and
Turret.
Rate Gyro
• Its function is to maintain the balance of turret in fixed position during
jerks and pit holes, and provide gun enough power to maintain its
position during tilted paths.

13. Working of Testing Jig
Traverse Output
• Optimum Range 6V-35.5 V
• Checked on W6 (pin 14 with 23, 24 shorted) for left
• Checked on W6 (pin 14 with 25, 26 shorted) for right
• In case of any error, change amplifier power
Elevation Output
• Optimum Range 6V-35.5V
• Checked on W6 (pin 17 with 10, 11 shorted) for up
• Checked on W6 (pin17 with 12, 13 shorted) for down
• In case of any error, change amplifier power
DC/AC Supply Checking
• The DC range should be around 22-28 V.
• The AC range should be around 38-44 V.
• In case of any error, the possible reason could be that convertor is damaged.
Rate Gyro Signal
• Range should be around 0-10V.
• It is checked on W2 12th pin.

14. Working of Testing Jig
Compensator
• Range should be 0-450 mV.
• Checked on W6 (pin 39 with 2, 3 shorted) for up
• Checked on W6 (pin 39 with 4, 5 shorted) for down
GSD Signal
• 24 V optimum
• Checked on W2 19th pin.
• In case of error, electromagnet might be damaged.
DC/AC Supply Checking
• The DC range should be around 22-28 V.
• The AC range should be around 38-44 V.
• In case of any error, the possible reason could be that convertor is damaged.
Rate Gyro Signal
• Range should be around 0-10V.
• It is checked on W2 12th pin.