Sunday, March 16, 2008


I. Introduction
A tank is a large armoured vehicle with treads, a rotating turret, and a heavy gun. The objective of this project is to create a model tank that moves in much the same way as a real tank would. This model tank will be able to move forward and backward, and turn left and right. The tank will initially have two motors that will each move a respective tread, one will control the left tread while the other will move the right tread. The tank’s movement will be controlled using a computer which will be connected to the circuit that controls the tank’s motors.

Tank’s Movement

II. Methodology
Materials Used:
1 x Model Tank (T-55 Finish Army)
1 x Project Bread Board
2 x Motors
3 x TIP41C 3 x 470Ω Resistors
3 x 2N2222 3 x 2.2kΩ Resistors
3 x 4N25 3 x SD205P Relays

The circuit for this project is divided into three main relays. Each relay, which serves a different function, is controlled using a transistor circuit connected to the computer. The first relay controls the flow from the power supply. When this transistor is off, the flow from the power supply remains the same. When it’s turned on, the flow from the power supply is reversed. Switching the flow of power controls the direction the motors will move, whether clockwise or counter-clockwise. The two other relays each control a motor. When these relays are off, the motors do not receive power. However, when they’re turned on, the motors receive power and thus move according to the power flow. The combination of turning these relays on or off determines the movement of the tank as seen in the table.

Relay 1 (Power) Relay 2 (Motor) Relay 3 (Motor) Movement
Off Off Off Stop
Off On On Forward
On On On Backward
Off On Off Turn Right
Off Off On Turn Left

The program which controls the circuit was created using C++. The program requires a decimal integer input from the user. This input represents a specific movement for the tank.

Decimal Input Binary Equivalent Movement
0 000 Stop
1 001 Turn Left
2 010 Turn Right
3 011 Forward
7 111 Backward

The decimal inputs are actually converted to binary values. These binary values determine whether a relay is turned on or off. Each bit represents one relay. The most significant bit represents the first relay which controls the flow from the power supply while the other bits represent the motor relays.

III. Conclusion
This has been a very fun and interesting group project. Our tank worked according to plan. However, during one of the tests, one of our motor system’s gears got damaged. In the future, it would be better to replace the current plastic gears with the appropriate metal gears to make the system more stable.
All in all, this project was a success! We were able to create the model that we planned from the start and we had lots of fun doing it!

Thursday, March 13, 2008

First Set of Pictures

Transistor Circuit

Tank’s Dual Motor System

Tank’s Dual Motor System

Relay Circuit

Circuit with Tank

Tank Front View


Tank Side View

Tank Side View