Servomotors are available as AC or DC motors. Early servomotors were generally DC motors because the only type of control for large currents was through SCRs for many years. As transistors became capable of controlling larger currents and switching the large currents at higher frequencies, the AC servomotor became used more often. Early servomotors were specifically designed for servo amplifiers. Today a class of motors is designed for applica-tions that may use a servo amplifier or a variable-frequency controller, which means that a motor may be used in a servo system in one application, and used in a variable-frequency drive in another application. Some companies also call any closed-loop system that does not use a stepper motor a servo system, so it is possible for a simple AC induction motor that is connected to a velocity controller to be called a servomotor.
This file is distributed in the hope that it will be useful, but WITHOUT
* WARRANTY OF ANY KIND.
*
* Author(s): Ole Saether
*
* DESCRIPTION:
*
* Hello World program. Please note that this program runs the internal 8051
* on the default power up frequency of 4MHz. See ex3c.c for an example on how
* to switch to 16MHz.
*
* The functionality is the same as in ex1a.asm.
*
* COMPILER:
*
* This program has been tested with Keil V7.07a.
*
* $Revision: 3 $
*
This file is distributed in the hope that it will be useful, but WITHOUT
WARRANTY OF ANY KIND.
Author(s): Ole Saether
DESCRIPTION:
nRF9E5 Hello World program. Please note that this program runs the internal
8051 on the default power up frequency of 4MHz. See ex3a.asm for an example
on how to switch to 16MHz.
The functionality is the same as in ex1c.c.
ASSEMBLER:
You need as31.exe to assemble this program. It can be downloaded from this
web page: http://www.pjrc.com/tech/8051/
$Revision: 4 $
Huffman codes
1.In telecommunication, how do we represent a set of messages, each with an access frequency, by a sequence of 0 s and 1 s?
2.To minimize the transmission and decoding costs, we may use short strings to represent more frequently used messages.
3.This problem can be solved by using an extended binary tree which is used in the 2-way merging problem.
the sourse code is
to encode and decode the Huffman.
This experiment uses the Blackfi n BF533/BF537 EZ-KIT to run a simple FIR fi lter on stereo
channels at a sampling frequency of 48 kHz. The
CYCLE register is embedded in the main
program (
process_data.c) to benchmark the time needed to process two FIR fi lters. A
background telemetry channel (BTC) is set up to display the cycle count.
This is IR (Infra-Red) learn module for home automation system. It can learn IR codes from different IR remotes, and then execute any assigned actions controlled by learned IR remote.
This project was developed using Keil 8051 compiler.
Processor - Atmel AT89C51
Frequency - 22.1184 Mhz (described as OSC_FREQ in "timer.h")
Timer 0 - system timer (used for timeouts and delays)
Also, look in folder /doc for additional information about IR codes formats and codes from different manufacturers.
This is a simple algorithm that downloads trading data from yahoo database. It is basically a large scale application of sqq.m which was originally submitted by Michael Boldin, link at acknowledgements.
Some of the functionalities of the package:
- User defined ticker list.
- Function for downloading most recent SP500 composition in ticker list.
- Control for bad data (e.g. a certain percentage of prices missing).
- Choice of frequency of data (e.g. weekly prices).
- Choice of starting and ending data.
- Function for saving the whole data in a pre-formatted excel file together with a full reports on missing data.
SPREAD SPECTRUM MODULATION TECHNIQUES
-spread spectrum - those modulation methods that are producing a signal whose
spectrum is more wider than of the data signal, the occupied frequency band being
independent by the signal of data band.
-The signals with spread spectrum of direct sequence type BPSK (BPSK-DS-SS)
-The signals with spread spectrum of direct sequence type QPSK – DS–SS
- Frequency hopping spread spectrum signals (FH-SS)
Spread-spectrum techniques are methods by which electromagnetic energy generated in a particular bandwidth is deliberately spread in the frequency domain, resulting in a signal with a wider bandwidth. These techniques are used for a variety of reasons, including the establishment of secure communications, increasing resistance to natural interference and jamming, and to prevent detec
In engineering, compensation is planning for side effects or other unintended issues in a design. The design of an invention can itself also be to compensate for some other existing issue or exception.
One example is in a voltage-controlled crystal oscillator (VCXO), which is normally affected not only by voltage, but to a lesser extent by temperature. A temperature-compensated version (a TCVCXO) is designed so that heat buildup within the enclosure of a transmitter or other such device will not alter the piezoelectric effect, thereby causing frequency drift.
Another example is motion compensation on digital cameras and video cameras, which keep a picture steady and not blurry.
