The work describes the development of a reliable device for profiling anion beam in the intensity cross section. A sensor head consisting of a Faraday cup in combination with a Channel Electron Multiplier was designed and built together with Continue reading
The remaining life assessment (RLA) process is a reliability prediction process, which predicts amount of life left in a system. Remaining life assessment is performed on hardware, which has already seen operational life.
This project details with the remaining life assessment process in detail and also provides a case study of remaining life assessment performed on Continue reading
The main aim of the project will be to design a SMS driven automatic display toolkit which can replace the currently used programmable electronic display. It is proposed to design receive cum display toolkit which can be programmed from an authorized mobile phone.
The message to be displayed is sent through a SMS from an Continue reading
Microelectronics have at all times been a complicated area in space technology, the radiation environment have always created heavy restriction. This is still true today, but development of new and better devices has steadily opened up this field for new applications.
FPGAs have been used in space for some time now, but that is mostly One-Time Programmable devices. Only a few reprogrammable FPGA have flown on real space missions, but in the near future this technology can Continue reading
This bachelor’s thesis has its main focus on the design and construction of hardware and software for the 2006 LTU Formula Student racing car. However, it also deals with the subject of microcontroller and electronics implementation in automobiles as well as a description of the Formula Continue reading
The following document details the research and evelopment of an Automatic Solar radiation tracker. Fossil fuels are a relatively short-term energy source; consequently, the uses of alternative sources such as solar energy are becoming more wide spread. To make solar energy more viable, the efficiency of solar array systems must be maximized. A feasible approach to maximizing the efficiency of solar array systems is sun tracking. Proposed in this report is a system that Continue reading
This thesis provides a method for electronically actuating the valves used in an internal combustion engine. This method for valve actuation looks at utilising the expected change to a 42V standard in motor vehicles. It also provides a simplified model elaborating how this principle works.
The advantage of electronic valve actuation is that it provides an easy method of infinitely varying the valve timing in internal combustion engines. The relationship between the desired open and shut intervals of the intake and exhaust valves vary with respect to engine speed. The current methods of valve actuation involve using an outdated mechanical method that ensures that the timing cannot readily be changed to suit the vehicle’s needs.
With more efficient timing intervals utilised, electronic valve actuation will lead to reduced fuel consumption and improved power in motor vehicles.
Author: Andrew John Gray
Source: The University of Queensland
Here is a circuit of a remote control unit which makes use of the radio frequency signals to control various electrical appliances. This remote control unit has 4 channels which can be easily extended to 12. This circuit differs from similar circuits in view of its simplicity and a totally different concept of generating the control signals. Usually remote control circuits make use of infrared light to transmit control signals. Their use is thus limited to a very confined area and line-of-sight.
This circuit makes use of radio frequency to transmit the control signals and hence it can be used for control from almost anywhere in the house. Here DTMF (dual-tone multi frequency) signals (used in telephones to dial the digits) are used as the control codes. The DTMF tones are used for frequency modulation of the carrier. At the receiver unit, these frequency modulated signals are intercepted to obtain DTMF tones at the speaker terminals. This DTMF signal is connected to a DTMF-to-BCD converter whose BCD output is used to switch-on and switch-off various electrical applicances (4 in this case). The remote control transmitter consists of DTMF generator and an FM transmitter circuit.
For generating the DTMF frequencies, a dedicated IC UM91214B (which is used as a dialler IC in telephone instruments) is used here. This IC requires 3 volts for its operation. This is provided by a simple zener diode voltage regulator which converts 9 volts into 3 volts for use by this IC. For its time base, it requires a quartz crystal of 3.58 MHz which is easily available from electronic component shops. Pins 1 and 2 are used as chip select and DTMF mode select pins respectively. When the row and column pins (12 and 15) are shorted to each other, DTMF tones corresponding to digit 1 are output from its pin 7. Similarly, pins 13, 16 and 17 are additionally required to dial digits 2, 4 and 8. Rest of the pins of this IC may be left as how they are. The output of IC1 is given to the input of this transmitter circuit which effectively frequency modulates the carrier and transmits it in the air. The carrier frequency is determined by coil L1 and trimmer capacitor VC1 (which may be adjusted for around 100MHz operation). An antenna of 10 to 15 cms (4 to 6 inches) length will be sufficient to provide adequate range. The antenna is also necessary because the transmitter unit has to be housed in a metallic cabinet to protect the frequency drift caused due to stray EM fields.
Four key switches (DPST push-to-on spring loaded) are required to transmit the desired DTMF tones. The switches when pressed generate the specific tone pairs as well as provide power to the transmitter circuit simultaneously. This way when the transmitter unit is not in use it consumes no power at all and the battery lasts much longer. The receiver unit contains an FM receiver (these days simple and inexpensive FM kits are readily available in the market which work exceptionally well), a DTMF-to-BCD converter and a flip-flop toggling latch section.
The frequency modulated DTMF signals are received by the FM receiver and the output (DTMF tones) are fed to the dedicated IC KT3170 which is a DTMF-to-BCD converter. This IC when fed with the DTMF tones gives corresponding BCD output; for example, when digit 1 is pressed, the output is 0001 and when digit 4 is pressed the output is 0100. This IC also requires a 3.58MHz crystal for its operation. The tone input is connected to its pin 2 and the BCD outputs are taken from pins 11 to 14 respectively. These outputs are fed to 4 individual D flip-flop latches which have been converted into toggle flip-flops built around two CD4013B ICs.
Whenever a digit is pressed, the receiver decodes it and gives a clock pulse which is used to toggle the corresponding flip-flop to the alternate state. The flip-flop output is used to drive a relay which in turn can latch or unlatch any electrical appliance. We can upgrade the circuit to control as many as 12 channels since IC UM91214B can generates 12 DTMF tones. For this purpose some modification has to be done in receiver unit and also in between IC2 and toggle flip-flop section in the receiver. A 4-to-16 lines demultiplexer (IC 74154) has to be used and the number of toggle flip-flops have also to be increased to 12 from the existing 4.
This is basically a flasher circuit modified to turn a bulb on and off instead of a LED. It uses a 555 timer IC working as an astable multivibrator. The flashing rate can be varied from very fast to maximum of once in 1.5 sec by varying the preset VR1.
The ON time of the circuit is given by:
TON= 0.69xC1x(R1 + VR1) second
and the OFF time is:
TOFF= 0.69xC1xVR1 second
You can increase the value of C1 to 100uF to get a slower flashing rate of upto once in 10 seconds.
In this modern world people are forced to use electronic devices in their daily life. Nowaday’s electronic voting machines are used for election. So we introduced a cellular voting machine based on microcontroller.
In this system there are two units, a master unit and a voting unit. The voting unit can be placed anywhere and the master unit is placed in a control room. The voting unit contains a DTMF coyer, which generates a DTMF tone and is transmitted to the master unit through the FM transmitter. The master contains a FM receiver, DTMF decoder, Micro controller and Display units. The tone from the voting unit is received by the receiver and is decoded and specific functions are carried out by micro controller and then it is displayed.
The aim of this project is to demonstrate the incorporation of computer method in railway traffic control to improve, safety, speed of handling the traffic and also reliability. Here we employ the microprocessor (Intel 8085) to handle the signaling, track changing and gate operation and to monitoring the traffic. The system starts with the tracking if the train is sensed at the station side or starts with the gate operation (i.e. gate opening and closing) along with the track changing if the train is sensed at the gate side. Once the train arrival is sensed at a distance of about 3 kms the microprocessor performs the gate operation along with the track changing, the identification of the train is done at a distance of 3 kms accordingly the particular operation is performed by the processor. Depending upon the priority of the incoming train, the unengaged track is given for train halting.
This thesis is focused on the control and modeling of a robots finger. The control target of this project is position tracking during the finger motion. A new sliding mode control algorithm is developed in this project. It originates from the author’s 3-stages approach. i.e. the reaching phase, the sliding mode and the steady state. This approach is mainly based on two key idea, as follows: (i) During the reaching phase, the speed of reaching can be related to the distance between the state trajectory and the switching manifold, (ii) During the sliding motion, the state velocity is directly related to the state variable for 2nd-order non linear systems.
This new control algorithm is a functional relationship for the speed of reaching during the reaching phase. The simulation result demonstrates that this algorithm performs better than Gao and Hung’s “power rate” reaching law both in chattering reduction and reaching time. The above robot finger is developed via the transition from a biological model for the human thumb to a mechanical prototype. A main concern of the biological model is the relationships on the excursion of finger tendons. The newly developed relationships in this project involves the shape and size of the associated phalanx, as well as the pulley mechanism besides the angle of rotation. The treatment of these relationships in this thesis are more complete and applicable than the approach by Landsmeer. Landsmeer’s model involves only the angle of rotation.
Moreover, the mechanical prototype developed in this project retains anthropomorphic features of the human thumb. Such features include the quad-circles at the ends of each piece, and the very low friction in motion via artificial tendons. These properties are unique in the above robot finger compared to the work on robot hands by other research groups. In addition, SMA-wires are used as actuator for the above robot finger. A major problem of the SMA material is the “residue” stress. This is a defect since it prevents the wire from returning to the same position before re-activation in the next cycle. Hence a new approach: the “interval insertion” method has been developed in this project. Implementations show that this method really solves the above stated problem.
Author: Loh, Albert Ming
Source: City University of Hong Kong
Dammann proposed the special type of diffraction grating which is periodic in nature together with binary phase for achieving a high splitting ratio. Later on, researchers proposed different kinds of methods for improving the performances. Dammann Gratings can be used in many areas, and in this project, we aim to Continue reading
Create a voice recorder using a PIC or a microcontroller and ADC. Use some conditioning circuits to condition the microphone output and feed it to the ADC. The converted values can be stored in some kind of memory. Samsung has some nice memory chips that can be easily interfaced. Most modern MP3 players use this kind of memory. Continue reading
In the modern digital age which belongs to the fast and competitive ones time became one of the expensive things to spend with. Everyone tries to minimize the amount of time they spend for every deal. So technologies are emerging to satisfy this desire of people. This project aims at the point of developing an electronic system which helps people to control any process or devices from a remote location using Continue reading