Unlock instant, AI-driven research and patent intelligence for your innovation.

A Design Method of Passive Linear Photoelectric Isolation Conversion Circuit

A technology of optoelectronic isolation and conversion circuit, applied in the direction of conversion equipment without intermediate conversion to AC, can solve the problems of complex circuit, large power consumption of circuit foundation, low cost, etc., to achieve simple circuit structure, small input voltage drop, etc. Small payload effect

Active Publication Date: 2016-12-14
河北珠峰仪器仪表设备有限公司
View PDF4 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The former signal is realized by optocoupler isolation. The working power of the circuit before and after isolation is generally obtained from the working power of the acquisition equipment through the DC / DC of the transformer isolation method; The linear segment and linearity of optocouplers are different, so it is difficult to achieve high linearity; the DC / DC conversion method of the power supply will inevitably introduce unnecessary power supply noise and reduce the system test accuracy
The power supply and signal of the latter generally adopt the form of transformer isolation. The circuit power supply before and after isolation is provided by the DC / DC of the system power supply through the transformer isolation mode. This method is convenient to realize multi-channel isolated output, but the circuit is complicated and the cost is high. There is also the disadvantage of DC / DC noise in the former method, which affects the system test accuracy.
The above two methods have more disadvantages: Although the measurement system and the system under test are electrically isolated, there is electromagnetic coupling signal transmission in the system before and after isolation, and the system under test is easily disturbed and affected by the measurement system. The safety and security are not high; due to the use of DC / DC power conversion, the basic power consumption of the circuit is large
Some instruments and meters with extremely strict control of circuit power consumption in flammable and explosive environments, this disadvantage is particularly obvious, and the above two methods will not be used

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
  • A Design Method of Passive Linear Photoelectric Isolation Conversion Circuit
  • A Design Method of Passive Linear Photoelectric Isolation Conversion Circuit
  • A Design Method of Passive Linear Photoelectric Isolation Conversion Circuit

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] Such as figure 1 As shown, the two-stage overvoltage and overcurrent π-type network protection circuit structure is composed of the two-stage fuse F1 and the limiting diode Z1, and the fuse F2 and the limiting diode Z1, respectively. The limiting diode Z1 is a bidirectional Schottky limiting diode .

[0023] The structure of the π-type network protection circuit and the diode rectifier bridge composed of four diodes D1 to D4 to overcome the polarity limit constitute the filter overvoltage protection circuit 1. The diodes D1 to D4 use Schottky barrier diodes to reduce the loop voltage. drop. Due to the filtering overvoltage protection circuit 1, the whole circuit can be connected to the circuit under test regardless of polarity.

[0024] Stealing power conversion circuit 2 includes a parallel-connected voltage regulator circuit Z2 with a wide working current range for realizing current source Ii-voltage source Uo conversion, and a voltage doubler or booster or negative...

Embodiment 2

[0058] Such as figure 2 As shown, the structure of this embodiment is basically the same as that of Embodiment 1. The difference is that due to the use of negative voltage conversion, the sampling resistor 5 is located at the current outflow end of the power stealing circuit 2, that is, one end of the sampling resistor 5 is connected to the power stealing circuit. The current outflow end of 2 is turned on, and the other end of the sampling resistor 5 is turned on with the output end of the filter overvoltage protection circuit, and is introduced into a photoelectric isolation stable amplifying circuit.

[0059] Different from Embodiment 1, the photoelectric isolation circuit 4 includes three photoelectric isolation circuits, and electrical isolation is used between the input and output of the three photoelectric isolation circuits and between the outputs of the two photoelectric isolation circuits; Optocouplers U4, U5, and U6 all use common photocouplers. The specific number...

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 is a design method of a passive linear photoelectric isolation conversion circuit. It includes at least a filter overvoltage protection circuit, a power stealing circuit, a photoelectric isolation stable amplifier circuit, and a photoelectric isolation circuit. The 4 to 20 mA current source is directly connected to the input terminal of the filter overvoltage protection circuit. The output terminal of the photoelectric isolation stable amplifier circuit is connected to the input terminal of the photoelectric isolation stable amplifier circuit, and the output terminal of the photoelectric isolation stable amplifier circuit drives several photoelectric isolation circuits. The circuit is connected in series with the filtering overvoltage protection circuit through the sampling resistor, and the other end of the sampling resistor is connected to the output terminal of the filtering overvoltage protection circuit, and is introduced into a photoelectric isolation stable amplifying circuit. The circuit has the advantages of simple circuit structure, high precision, good linearity, low cost and low power consumption.

Description

technical field [0001] The invention belongs to the field of electronic measurement and signal conversion, and relates to a design method of a passive linear photoelectric isolation conversion circuit. Background technique [0002] In modern industrial information automation data acquisition, 4~20mA current loop signal has become one of the main signal transmission standards, and the isolation and conversion of this signal is a common technical means to improve system security. There are two main methods of traditional analog signal linear isolation: one is to use photoelectric isolation, and the other is to use transformer isolation. The former signal is realized by optocoupler isolation. The working power of the circuit before and after isolation is generally obtained from the working power of the acquisition equipment through the DC / DC of the transformer isolation method; The linear segment and linearity of optocouplers are different, so it is difficult to achieve high l...

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 Patents(China)
IPC IPC(8): H02M3/10
Inventor 陈建文李文杰
Owner 河北珠峰仪器仪表设备有限公司