一種實用的微機自動配料秤系統(tǒng):介紹一種由單片機構(gòu)成的配料秤。敘述了秤的傳感器、變送器、信號的變換、硬件原理、軟件流程以及和DCS 系統(tǒng)構(gòu)成的單回路調(diào)節(jié)系統(tǒng),此系統(tǒng)可廣泛地應(yīng)用于各行業(yè)的配料控制中。關(guān)鍵詞:配料秤 單片機 單回路調(diào)節(jié)系統(tǒng) DCS 系統(tǒng)
Abstract :A proportioning weigher based on single chip computer is introduced. Sensors , transmitters , signal converting , principle of hardware ,software flowchart of proportioning weigher and single loop control system composed with DCS system are emphasized ,this system can be used in proportioning control of various trades extensively.Key Words :Proportioning Weigher ,Single Chip Computer ,Single Loop Control System ,Distributed Control System
Abstract: With industrial/scientific/medical (ISM) band radio frequency (RF) products, often times users are new to the structure of Maxim's low pin-count transmitters andfully integrated superheterodyne receivers. This tutorial provides simple steps that can be taken to get the best performance out of these transmitters and receivers whileproviding techniques to measure the overall capability of the design.
Abstract: This application note illustrates the flexibility of the MAX7060 ASK/FSK transmitter. While the currently available evaluationkit (EV kit) has been optimized for the device's use in a specific frequency band (i.e., 288MHz to 390MHz), this document addresseshow the EV kit circuitry can be modified for improved operation at 433.92MHz, a frequency commonly used in Europe. Twoalternative match and filter configurations are presented: one for optimizing drain efficiency, the other for achieving higher transmitpower. Features and capabilities of earlier Maxim industrial, scientific, and medical radio-frequency (ISM-RF) transmitters areprovided, allowing comparison of the MAX7060 to its predecessors. Several design guidelines and cautions for using the MAX7060are discussed.
The Inter IC bus or I2C bus is a simple bidirectional two wire bus designed primarily for general control
and data transfer communication between ICs.
Some of the features of the I2C bus are:
• Two signal lines, a serial data line (SDA) and a serial clock line (SCL), and ground are required. A
12V supply line (500mA max.) for powering the peripherals often may be present.
• Each device connected to the bus is software addressable by a unique address and simple
master/ slave relationships exist at all times masters can operate as master-transmitters or as
master-receivers.
• The I2C bus is a true multi-master bus including collision detection and arbitration to prevent data
corruption if two or more masters simultaneously initiate data transfer systems.
• Serial, 8-bit oriented, bidirectional data transfers can be made at up to 100 KBit/s in the standard
mode or up to 400 KBit/s in the fast mode.
This book gives a comprehensive overview of the technologies for the advances of
mobile radio access networks. The topics covered include linear transmitters,
superconducting filters and cryogenic radio frequency (RF) front head, radio over
fiber, software radio base stations, mobile terminal positioning, high speed
downlink packet access (HSDPA), multiple antenna systems such as smart
antennas and multiple input and multiple output (MIMO) systems, orthogonal
frequency division multiplexing (OFDM) systems, IP-based radio access networks
(RAN), autonomic networks, and ubiquitous networks.
The book you’re holding, physically or electronically, is the result of a very
interesting, challenging but also rewarding research project. The research was
carried out in different contexts and cooperations but it was centered around the
following question: how can we make the RF transmitters of our modern com-
munication systems (WiFi, GSM, LTE, and so on) more flexible and more efficient
at the same time.
At the macroscopic level of system layout, the most important issue is path loss. In the
older mobile radio systems that are limited by receiver noise, path loss determines SNR and
the maximum coverage area. In cellular systems, where the limiting factor is cochannel
interference, path loss determines the degree to which transmitters in different cells interfere
with each other, and therefore the minimum separation before channels can be reused.
