Manchester code. Modulation Modulation is a process of changing the characteristics of a radio wave to encode an information signal and sending that information to the other end. Readers send a continuous radio wave and the tags modulate this base band signal by adding encoded information into it, which the readers decode. Modulation schemes used for RF communication are amplitude shift keying (ASK), frequency shift keying (FSK) and phase shift keying (PSK). The modulation technique’s choice is
originating from a data sources like computer etc. or it can be in analog form such as a video/audio signal which is then digitized into a bit-stream by using modulation techniques or source coding schemes like data compression and analog to digital conversion. The modern modulation techniques include pulse width and pulse code modulation. The codec equipment helps in carrying out the source coding and decoding work. Common examples of communication channels are optical fibers, copper wires, computer
components of DC power supplies and high-voltage direct current power transmission system. Because of the alternating nature of the input AC sine wave, the process of rectification alone produces a DC current that, though unidirectional, consists of pulses of current. Rectifiers have many applications such as power supplies for radio, television and computer equipment, require a steady constant DC current (as would be produced by a battery). In these applications the output of the rectifier is smoothed
advantages of this paper is that, uses only one DC input, one three phase transformer and minimum number of power switches (15 switches). For the proper inverter operation, high quality the gating pulses to be generated to the inverter switches. For generating gating pulses, Space Vector Pulse Width Modulation (SVPWM) techniques have been used. This paper proposes comparative studies of three phase PV inverter using PI and fuzzy logic controller and switching losses are also
performance MPPT includes pulse width modulation (PWM) used in large scale PV module, whereas low performance MPPT includes pulse frequency modulation (PFM) used in small scale PV module. PFM is used instead of PWM to attain better efficiency at low power levels. PWM continuously activate the switches of the converter at a fixed frequency whereas PFM adjusts the switching activity of the available power. Higher ripple current can be produced for the frequency modulation which reduces the efficiency
Chapter 1: Introduction 1.1 Background of study Induction Motors are widely used in industrial applications. It has been reported that they have a motor market share of approximately 80 percent. Their popularity stems from robust construction, low cost and ease of maintenance. As induction motors operate at a constant speed, they provide efficient operation in industrial applications if the loads that they drive remain fairly constant. However, the loads vary when the process conditions change during
is controlled by DC, and Alternating Current (AC) servo motor which is controlled by AC. The servo motor “internal” positional feedback consists of either encoder feedback or voltage feedback. The built-in encoder inside the servo motor provides a pulse signal that is processed by the servo controller to get the position feedback. The voltage feedback consists of a built-in potentiometer which is coupled with the servo motor axis to get the relative angular position depending on the value of the potentiometer
as their phase, amplitude, frequency, or pulse width. If radio waves passing an electrical conductor, the oscillating fields induce an alternating current in the conductor. The information in the waves can be get back into its original form. Radio systems must have transmitter to modulate some property of the energy produced to impress a signal on it. To using amplitude modulation or angle modulation ,which can be frequency modulation or phase modulation. Radio systems have antenna to convert
1. Electrical Drives: Systems which employed for motion control are called as Drives. Drives employ any of the prime movers for deliverying mechanical energy for motion control like Diesel engines, steam turbines and electric motors. Drives which employ electric motors are called as Electrical Drives. Basically Drive is a combination of various systems combined together for the purpose of motion control. Electrical drives are available with vast range of torque, speed and potential. Can employed
speaker or an alternating current (sine wave) traveling on a wire. Digital signal, on the other hand is a digital representation of an analog signal, it is either off or on. AM - Amplitude modulation and FM Frequency modulations are means by which use to transmit analog signal. DM Digital modulation is used to transmit digital signal (Analog vs Digital Transmission, 2005) X on and X off: X on / X off is a handshaking control signal used to control the flow of data communication. It works
The Intel MCS-51, commonly known as the “8051”, is a single chip microcontroller which was developed by Intel in 1980 for use in embedded systems. This “system on chip” accommodates 128 bytes of RAM, 4Kbytes of ROM, 2 Timers, 1 Serial port, and four ports on a single chip.[1] The rise in popularity and success of the 8051 brought forth different versions of the microcontroller from other manufacturers (Intel permitted so). Its popularity remains to this day for it provides a marketable availability
reproducing the digitally recorded analog signal without being noticeably different to the or... ... middle of paper ... ...Vardalas, "Pulse Code Modulation: It all Started 75 Years Ago with Alec Reeves," IEEE, June 2012. [Online]. Available: http://www.todaysengineer.org/2012/Jun/history.asp. [Accessed 14 November 2013]. [18] Library of Congress, "Linear Pulse Code Modulated Audio (LPCM)," National Digital Information Infrastructure and Preservation Program, 19 February 2008. [Online]. Available:
The interleaved buck converter with continuous supply current has been shown in Fig.3. The topology consists of two input capacitors Cin1 and Cin2, two switches Q1 and Q2 which are triggered 180 degrees apart, two freewheeling diodes D1 and D2, two phase inductors L1 and L2, an output inductor Lo and an output capacitor Co. The voltage stress experienced by the switches and diodes are reduced due to the presence of the input capacitors. In the interleaved structure the current flowing through the
Power Semiconductor Devices Introduction Today there are many power semiconductor devices used in different applications of power conversion. The diode is one of the oldest semiconductors devices and is still wildly used today in power electronics. Diodes are found in virtually all power converts in one form or another. For this reason our discussion will be focused on the application of power diodes. Power Diodes are two terminal electronic devices that permit current flow in predominantly
2.1 (c) Total Harmonics Distortion (THD) The total harmonic distortion is calculated as the ratio of the rms value of its total harmonic component of the output voltage and the rms value of the fundamental component. A total harmonics distortion is an evaluate of closeness in a shape between the output voltage waveform and its fundamental components. THD=√(E_rms^2-E_1^2 )/(E_rms^1 ) 2.1 (d) Distortion Factor (DF) A distortion factor shows the amount of harmonics that remain in the output voltage
with two floating paddles and ball that bounced off the walls. A sonar-blip was emitted every time the ball was repelled by a paddle. In 1978, the Space Invaders arcade introduced the first sound track in video game history. Only a quickening pulse can be heard as the aliens get closer and closer to Earth. This was also the first instance of interactive sound for video games, when the music changes while it is playing. 1980 brought the debut of the classic Pac Man arcade. A short, catchy