介紹一種無(wú)極可調(diào)交流電子負(fù)載設(shè)計(jì)的新方法，由ATmega48單片機(jī)輸出PWM波，通過(guò)上位機(jī)設(shè)定不同的占空比控制場(chǎng)效應(yīng)管的通斷時(shí)間，即改變流過(guò)場(chǎng)效應(yīng)管的平均電流。根據(jù)電流的大小，可以等效為相應(yīng)的負(fù)載，并將采集的電流值顯示在上位機(jī)上。文中對(duì)該系統(tǒng)的軟﹑硬件設(shè)計(jì)思路作了詳細(xì)的分析，闡述了其設(shè)計(jì)原理。
Abstract:
A new type electronic load is introduced.Due to ATmega48 microcomputer output PWM wave.The different duty is set ratio through PC to control FET turn-on time.We can equivalent homologous load according the current and display the current at PC.The hardware and software designing are analysed in detail. The principle is explained and the output is also given.
Integrated EMI/Thermal Design forSwitching Power SuppliesWei ZhangThesis submitted to the Faculty of theVirginia Polytechnic Institute and State Universityin partial fulfillment of the requirements for the degree of
Integrated EMI/Thermal Design forSwitching Power SuppliesWei Zhang(ABSTRACT)This work presents the modeling and analysis of EMI and thermal performancefor switch power supply by using the CAD tools. The methodology and design guidelinesare developed.By using a boost PFC circuit as an example, an equivalent circuit model is builtfor EMI noise prediction and analysis. The parasitic elements of circuit layout andcomponents are extracted analytically or by using CAD tools. Based on the model, circuitlayout and magnetic component design are modified to minimize circuit EMI. EMI filtercan be designed at an early stage without prototype implementation.In the second part, thermal analyses are conducted for the circuit by using thesoftware Flotherm, which includes the mechanism of conduction, convection andradiation. Thermal models are built for the components. Thermal performance of thecircuit and the temperature profile of components are predicted. Improved thermalmanagement and winding arrangement are investigated to reduce temperature.In the third part, several circuit layouts and inductor design examples are checkedfrom both the EMI and thermal point of view. Insightful information is obtained.
NORTi3 is a realtime multitasking operating system conforming to the micro-ITRON 3.0
specification. NORTi3 is divided into two packages: NORTi3 Standard and NORTi3 Extended. The
product NORTi3 Extended has implemented all the system calls of level E placed as "added and
extended functions” in the micro-ITRON specification as well as the system calls equivalent to level X.
Frequency Scale Conversion
From f To f Scale
frq2mel mel2frq mel The mel scale is based on the human perception of sinewave pitch.
frq2erb erb2frq erb The erb scale is based on the equivalent rectangular bandwidths of the human ear.
frq2midi midi2frq midi The midi standard specifies a numbering of semitones with middle C being 60. They can use the normal equal tempered scale or else the pythagorean scale of just intonation. They will in addition output note names in a character format.
Introducing a new product requires the designer to think about the product differentiators. Designing a user-friendly product, considering all other features are equivalent, will help increase the product acceptance and sales. A good User Interface is definitively one of these differentiators. In many instances, a Graphical User Interface (GUI) is the best approach.
The paper presents the CORDIC Algorithm, which has been implemented as an virtual component (IP core) in a VHDL simulation environment. The core is packaged as a soft (VHDL) macro and it implements all transcenden-tal functions. Analysis of the accuracy of the algorithms implemented shows that the CORDIC functions are equivalent to the accuracy of a Pentium coprocessor.
Laser Control is a java program that using a webcam detects when a laser pointer is in a specified hotspot and then does the equivalent of pressing a specified keyboard key. thus controlling Media Portal through it s hot keys. the hotspots can be set by the user as well as the actions taken. Make your wall into a remote controll.
This application report presents basic code for initializing and operating the TMS320LF240x DSP devices. Two functionally equivalent example progra ms are presented: one written in assembly language and the other in C language. Detailed discussions of each program are provided that explain numerous compiler and assembler directives, code requirements, and hardware-related requirements. The programs are ready to run on either the TMS320LF2407 Evaluation Module (EVM) or the eZdsp LF2407 development kit. However, they are also intended for use as a code template for any TMS320LF240x (LF240x) or TMS320LF240xA (LF240xA) DSP target system.
MTOOLS
version 2.0
Mtools is a public domain collection of programs to allow Unix systems
to read, write, and manipulate files on an MSDOS filesystem (typically a
diskette).
The following MSDOS commands are emulated:
Mtool MSDOS
name equivalent Description
----- ---- -----------
mattrib ATTRIB change MSDOS file attribute flags
mcd CD change MSDOS directory
mcopy COPY copy MSDOS files to/from Unix
mdel DEL/ERASE delete an MSDOS file
mdir DIR display an MSDOS directory
mformat FORMAT add MSDOS filesystem to a low-level format
mlabel LABEL make an MSDOS volume label.
mmd MD/MKDIR make an MSDOS subdirectory
mrd RD/RMDIR remove an MSDOS subdirectory
mread COPY low level read (copy) an MSDOS file to Unix
mren REN/RENAME rename an existing MSDOS file
mtype TYPE display contents of an MSDOS file
mwrite COPY low level write (copy) a Unix file to MSDOS
*** *** *** *** *** *** *****
** Two wire/I2C Bus READ/WRITE Sample Routines of Microchip s
** 24Cxx / 85Cxx serial CMOS EEPROM interfacing to a
** PIC16C54 8-bit CMOS single chip microcomputer
** Revsied Version 2.0 (4/2/92).
**
** Part use = PIC16C54-XT/JW
** Note: 1) All timings are based on a reference crystal frequency of 2MHz
** which is equivalent to an instruction cycle time of 2 usec.
** 2) Address and literal values are read in octal unless otherwise
** specified.
