PWM wave based multi-channel 4-20 mA control command converting system

A technology of control command and conversion system, applied in the direction of output power conversion devices, electrical components, etc., can solve the problems of 4-20mA signal conversion circuit accuracy not reaching power electronic devices, high price, low reliability, etc. Anti-interference ability, less pulsating components, and reliable operation

Active Publication Date: 2018-03-06
WUHAN UNIV OF TECH
View PDF4 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] However, in operation practice, it is found that if no necessary measures are taken, the accuracy of the 4-20mA signal conversion circuit based on PWM waves cannot meet the control technical requirements of power electronic devices, and an external conversion module has to be used, although the accuracy has been improved. Further improvement, but the price is generally more expensive, especially with the increase of the number of channels, it not only increases the cost, but also because of the additional conversion module, it is not easy to use, the failure rate is high, and the reliability is low

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • PWM wave based multi-channel 4-20 mA control command converting system
  • PWM wave based multi-channel 4-20 mA control command converting system
  • PWM wave based multi-channel 4-20 mA control command converting system

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0068] The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings. It should be noted here that the descriptions of these embodiments are used to help understand the present invention, but are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0069] Such as figure 1 Shown is a schematic diagram of the principle of a specific implementation of the multi-channel conversion system. The multi-channel conversion system of the present invention includes a controller unit (1), a level conversion unit (2), an isolation conversion unit (3), a low-pass filter unit (4), a 4-20mA voltage / current conversion unit (5), a current The signal transmission cable (6) and the load interface unit (7) consist of seven components in total.

...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention provides a PWM wave based multi-channel 4-20 mA control command converting system. The system includes a controller unit (1), an electric level converting unit (2), an isolation conversion unit (3), a low-pass filtering unit (4), a 4-20 mA voltage / current converting unit (5), a current signal transmission cable (6) and a load interface unit (7) connected in sequence. The system is applied as a CPU into an ARM in an embedded system widely with high performance and at a low cost, multi-channel PWM wave voltage signals of required (fixed) frequency and adjustable duty ratio are generated from multi-channel PWM waveforms of TIM<X> of the ARM and are converted to multi-channel 4-20 mA current output signals. The anti-interference capability is improved and multi-channel long-distance transmission is realized. Besides, the system is high in control precision, stable in performance and reliable in operation.

Description

technical field [0001] The invention belongs to the technical field of power electronic conversion and control, in particular to a multi-channel 4-20mA control command conversion system based on PWM waves. Background technique [0002] It is generally necessary to measure various non-electrical physical quantities (such as temperature, pressure, speed, angle, etc.) and electrical physical quantities (such as voltage, current, resistance, magnetic induction, etc.) Transmitter equipment) to convert them into analog electrical signals that are easy to transmit. The practice of industrial field operation shows that to reliably, safely and healthily transmit the above-mentioned physical quantities to the control room or display and control device hundreds of meters away, the most common method is to use 4-20mA current for transmission. The reasons are: [0003] (1) The transmitted analog quantity is not easy to be disturbed, because the amplitude of the noise voltage in the indu...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): H02M1/00H02M1/08
CPCH02M1/00H02M1/08H02M1/0012
Inventor 李维波华逸飞余万祥康兴李巍何凯彦
Owner WUHAN UNIV OF TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap