EE213 Term Project 2014 2015
EE213 Electrical Circuits Laboratory Term Project
Two Speed Automatic Transmission System
1. Introduction
Transmission system is an assembly of gears, shafts and electrical gadgets in an automobile. This system forms a bridge between the engine and wheels to transmit mechanical power required for movement. The complete set up reduces the high rotational speed of engine to lower wheel speed, since internal combustion engines in automobiles operate between 600 and 7000 revolutions per minute (rpm) whereas wheels rotate between 0 and
1800 rpm [1]. Moreover, transmission ensures the proper amount of torque according to the speed of the car. For example, greatest torque is required to move the car from rest; however, one needs greater rpm for high speeds.
A transmission may have multiple gear ratios that require switching as the speed varies. Switching can be done manually (by the driver) or automatically. In any case, there are usually a speedometer and a tachometer in front of the operator that display the speed of the automobile and rotation count of the engine, respectively.
Figure 1: Illustration of the manual transmission [2]
2. Term Project Description
In this project, you will simulate the tachometer of an automobile with automatic transmission.
The simulation will be done for two different gear ratios, one of which represents low-speed/high-torque while the other stands for high-speed/low-torque. The variation of the DC level of a periodic voltage waveform will represent the variation of engine rpm. As soon as the DC level goes out of the predefined voltage range, your system should change the gear accordingly and engine rpm should be demonstrated by making use of the analog multimeters in the laboratory.
The system consists of four main blocks and the overall block diagram is given in Figure 2.
Variable Duty Cycle
Generator
DC Level Detector
Automatic Shifting
Mechanism
Figure 2 - System Block Diagram
Tachometer
2.1 Variable DC Voltage Generator
The
Two Speed Automatic Transmission System
1. Introduction
Transmission system is an assembly of gears, shafts and electrical gadgets in an automobile. This system forms a bridge between the engine and wheels to transmit mechanical power required for movement. The complete set up reduces the high rotational speed of engine to lower wheel speed, since internal combustion engines in automobiles operate between 600 and 7000 revolutions per minute (rpm) whereas wheels rotate between 0 and
1800 rpm [1]. Moreover, transmission ensures the proper amount of torque according to the speed of the car. For example, greatest torque is required to move the car from rest; however, one needs greater rpm for high speeds.
A transmission may have multiple gear ratios that require switching as the speed varies. Switching can be done manually (by the driver) or automatically. In any case, there are usually a speedometer and a tachometer in front of the operator that display the speed of the automobile and rotation count of the engine, respectively.
Figure 1: Illustration of the manual transmission [2]
2. Term Project Description
In this project, you will simulate the tachometer of an automobile with automatic transmission.
The simulation will be done for two different gear ratios, one of which represents low-speed/high-torque while the other stands for high-speed/low-torque. The variation of the DC level of a periodic voltage waveform will represent the variation of engine rpm. As soon as the DC level goes out of the predefined voltage range, your system should change the gear accordingly and engine rpm should be demonstrated by making use of the analog multimeters in the laboratory.
The system consists of four main blocks and the overall block diagram is given in Figure 2.
Variable Duty Cycle
Generator
DC Level Detector
Automatic Shifting
Mechanism
Figure 2 - System Block Diagram
Tachometer
2.1 Variable DC Voltage Generator
The
References: 1. http://en.wikipedia.org/wiki/Transmission_(mechanics) 2. http://repairpal.com/manual-transmission 3. http://www.electronics-tutorials.ws/blog/pulse-width-modulation.html