-
The use of light to send messages is not new. Fires were used for signaling in
biblical times, smoke signals have been used for thousands of years and flashing
lights have been used to communicate between warships at sea since the days of
Lord Nelson.
The idea of using glass fibre to carry an optical communications signal originated
with Alexander Graham Bell. However this idea had to wait some 80 years for
better glasses and low-cost electronics for it to become useful in practical
situations.
標簽：
Communications
Understanding
Optical
上傳時間：
2020-06-01
上傳用戶：shancjb
-
Telecommunications is today widely understood to mean the electrical means of
communicating over a distance. The first form of telecommunications was that of
the Telegraph, which was invented quite independently in 1837 by two scientists,
Wheatstone and Morse. Telegraphy was on a point-to-point unidirectional basis and
relied on trained operators to interpret between the spoken or written word and the
special signals sent over the telegraph wire. However, the use of telegraphy did
greatly enhance the operations of railways and, of course, the dissemination of news
and personal messages between towns.
標簽：
Telecommunications
Understanding
Networks
上傳時間：
2020-06-01
上傳用戶：shancjb
-
Digital radios have undergone an astonishing evolution in the last century. Born as a set of simple and
power-hungry electrical and electromechanical devices for low data rate transmission of telegraph data
in the Marconi age, they have transformed, thanks to substantial advances in electronic technology,
into a set of small, reliable and sophisticated integrated devices supporting broadband multimedia
communications. This, however, would not have been possible unless significant progress had been
made in recent decades in the field of signal processing algorithms for baseband and passband signals.
In fact, the core of any modern digital radio consists of a set of algorithms running over programmable
electronic hardware. This book stems from the research and teaching activities of its co-authors in
the field of algorithmic techniques for wireless communications. A huge body of technical literature
has accumulated in the last four decades in this area, and an extensive coverage of all its important
aspects in a single textbook is impossible. For this reason, we have selected a few important topics
and, for ease of reading, organized them into two parts.
標簽：
Communications
Algorithmic
Techniques
Wireless
上傳時間：
2020-06-01
上傳用戶：shancjb
-
Radio frequency identification (RFID) is a type of automatic identification systems
which has gained popularity in recent years for being fast and reliable in keeping
track of the individual objects. In RFID systems, contactless object identification
is achieved using radio signals without the need for physical contact as the case
with other existing identification technologies such as barcodes. Therefore, a huge
number of items can be identified in a short amount of time with high reliability
and low cost which makes the RFID technology very attractive for a wide range of
applications such as supply chain management, e-health, monitoring humans, pets,
animals, and many other objects, toll control, and electrical tagging. Furthermore,
RFID technology eliminates the human error and reduces the total cost of the
products.
標簽：
Security
RFID
上傳時間：
2020-06-08
上傳用戶：shancjb
-
The purpose of this book is to present detailed fundamental information on a
global positioning system (GPS) receiver. Although GPS receivers are popu-
larly used in every-day life, their operation principles cannot be easily found
in one book. Most other types of receivers process the input signals to obtain
the necessary information easily, such as in amplitude modulation (AM) and
frequency modulation (FM) radios. In a GPS receiver the signal is processed
to obtain the required information, which in turn is used to calculate the user
position. Therefore, at least two areas of discipline, receiver technology and
navigation scheme, are employed in a GPS receiver. This book covers both
areas.
標簽：
Fundamentals_of_Global_Positionin
g_System_Receivers
上傳時間：
2020-06-09
上傳用戶：shancjb
-
Have you ever looked at some gadget and wondered
how it really worked? Maybe it was a remote control
boat, the system that controls an elevator, a vending
machine, or an electronic toy? Or have you wanted
to create your own robot or electronic signals for a model railroad, or per-
haps you’d like to capture and analyze weather data over time? Where and
how do you start?
標簽：
Introduction
Workshop
Hands-On
Arduino
上傳時間：
2020-06-09
上傳用戶：shancjb
-
Control systems are used to regulate an enormous variety of machines, products, and
processes. They control quantities such as motion, temperature, heat flow, fluid flow,
fluid pressure, tension, voltage, and current. Most concepts in control theory are based
on having sensors to measure the quantity under control. In fact, control theory is
often taught assuming the availability of near-perfect feedback signals. Unfortunately,
such an assumption is often invalid. Physical sensors have shortcomings that can
degrade a control system.
標簽：
Observers
Control
Systems
in
上傳時間：
2020-06-10
上傳用戶：shancjb
-
This design uses Common-Emitter Amplifier (Class A) with 2N3904 Bipolar Junction Transistor.
Use “Voltage Divider Biasing” to reduce the effects of varying β (= ic / ib) (by holding the Base voltage constant)
Base Voltage (Vb) = Vcc * [R2 / (R1 + R2)]
Use Coupling Capacitors to separate the AC signals from the DC biasing voltage (which only pass AC signals and block any DC component).
Use Bypass Capacitor to maintain the Q-point stability.
To determine the value of each component, first set Q-point close to the center position of the load line. (RL is the resistance of the speaker.)
標簽：
音頻放大器設計
電路圖
英文
上傳時間：
2020-11-27
上傳用戶：
-
電子書-RTL Design Style Guide for Verilog HDL540頁A FF having a fixed input value is generated from the description in the upper portion of
Example 2-21. In this case, ’0’ is output when the reset signal is asynchronously input,
and ’1’ is output when the START signal rises. Therefore, the FF data input is fixed at
the power supply, since the typical value ’1’ is output following the rise of the START
signal.
When FF input values are fixed, the fixed inputs become untestable and the fault detection rate drops. When implementing a scan design and converting to a scan FF, the scan
may not be executed properl not be executed properly, so such descriptions , so such descriptions are not are not recommended. recommended.[1] As in the lower
part of Example 2-21, be sure to construct a synchronous type of circuit and ensure that
the clock signal is input to the clock pin of the FF.
Other than the sample shown in Example 2-21, there are situations where for certain
control signals, those that had been switched due to the conditions of an external input
will no longer need to be switched, leaving only a FF. If logic exists in a lower level and a
fixed value is input from an upper level, the input value of the FF may also end up being
fixed as the result of optimization with logic synthesis tools. In a situation like this, while
perhaps difficult to completely eliminate, the problem should be avoided as much as possible.
標簽：
RTL
verilog hdl
上傳時間：
2022-03-21
上傳用戶：canderile
-
隨著科技發展及工業4.0 進程推進,機械臂應用范圍越來越廣,并演化出各種各樣的機械臂,如碼垛機械臂、焊接機械臂、裝配機械臂以及手術機械臂等。現利用solidworks 進行三維建模,設計制作一款基于stm32f103c8t6 單片機的主從式桌面級機械臂,該機械臂包括一個主動機械臂和一個從動機械臂,采用藍牙傳輸信號方式進行同步運動,并且詳細介紹了該機械臂材料選擇、結構設計、工作原理、組成部分和設計特點。With the development of science and technology and the advancement of Industry 4.0, the application range of the mechanical arm has become wider and wider, and various types of mechanical arms, such as palletizing robot arms, welding robot arms, assembly robot arms, and surgical robot arms, have been developed. Now using solidworks for 3D modeling, design and manufacture a master-slave desktop-level robot arm based on stm32f103c8t6 single-chip microcomputer. The robot arm includes an active robot arm and a slave robot arm, which uses Bluetooth to transmit signals for synchronous motion. The material selection, structural design, working principle, components and design features of the manipulator are introduced.
標簽：
stm32f103c8t6
單片機
上傳時間：
2022-03-27
上傳用戶：
