CN204855007U - Thermal resistance isolated safety barrier - Google Patents

Abstract

The utility model provides a thermal resistance isolated safety barrier, includes power supply circuit, explosion -proof processing module, resistance voltage conversion module, filter amplifier module, signal acquisition module, central processing unit, signal isolation module, resistance capacitance integrating circuit, voltage -current conversion module, output circuit. Thermal resistance isolated safety barrier, simple structure, low in production cost, temperature characteristic is good, the response is fast, the low -power consumption, keep apart effectually and the reliability is high.

Description

A kind of thermal resistance isolating safety grid

Technical field

The utility model relates to a kind of safety barrier, particularly a kind of thermal resistance isolating safety grid.

Background technology

Safety barrier also known as safety holder, the safe interface in intrinsic safety loop, it can between place of safety and explosive area bi-directional electric signal, and the place of safety caused because of fault can be limited pass on to the energy in explosive area.Be divided into two large classes by the full grid of structure: a class is Zener type safety barrier, its principle is simple, circuit realiration is easy, cheap, but be greatly affected because of the reliability in making it apply due to the defect of himself principle, and limit its range of application.Isolating safety grid have employed input, exports and the circuit structure of power supply mutual electrical isolation three party, meets the requirement of intrinsic safety type restriction energy simultaneously.With Zener type safely compared with, isolating safety grid has outstanding advantage and more extensive use, although its price is a little more than Zener type safety barrier, from design, construction and installation, debug and be maintained as original consideration, its integrated cost is on the contrary lower than Zener type safety barrier.Requiring that higher engineering site almost have employed isolating safety grid bar none as main intrinsic safe explosion-proof instrument, isolating safety grid instead of Zener type safety barrier gradually, obtains increasingly extensive application in safety anti-explosive field.

Safety barrier is widely used in the industrial instrument front end signal process in the field such as explosion-proof, for raising industrial processes automatic control system antijamming capability, Guarantee control system stability and reliability have very important effect, but current safety barrier has the following disadvantages: power consumption is large, poor stability, temperature characterisitic is poor, poor anti jamming capability, output shift is large, easily breaks down; In addition output power is little, and current-limiting resistance is comparatively large, and thermal value is many, and resistance temperature rise is too high; And small product size is comparatively large, is unfavorable for in-site installation.

Utility model content

Utility model object: in order to overcome above deficiency, the purpose of this utility model is to provide a kind of thermal resistance isolating safety grid, this thermal resistance isolating safety grid isolation effect is good, reliability is high, good temp characteristic, response are fast, low-power consumption, isolating safety grid that production cost is low.

Technical scheme: a kind of thermal resistance isolating safety grid, comprises power circuit, technological processing for explosion protection feature module, resistive voltage modular converter, filter and amplification module, signal acquisition module, central processing unit, signal isolation module, resistance capacitance integrating circuit, Voltage to current transducer module, output circuit; The output terminal of described power circuit connects the input end of technological processing for explosion protection feature module, central processing unit and signal isolation module respectively; The output terminal contact resistance voltage transformation module input end of described technological processing for explosion protection feature module; The output terminal of described resistive voltage modular converter connects the input end of filter and amplification module; The input end of the output terminal connection signal acquisition module of described filter and amplification module; The output terminal of described signal acquisition module connects the input end of central processing unit; The input end of the output terminal connection signal isolation module of described central processing unit; The input end of the output terminal contact resistance capacitance integral circuit of described signal isolation module; The output terminal of described resistance capacitance integrating circuit connects the input end of Voltage to current transducer module; The output terminal of described Voltage to current transducer module connects output circuit.Thermal resistance isolating safety grid described in the utility model, structure is simple, and production cost is low.Wherein input end, output terminal and power end three end be separated, after the conversion of thermometric thermal resistance signal is amplified, compensated by the nonlinear relationship of linear circuit to temperature and resistance again, the constant current signal of 4 ~ 20mA that output one is linear with dut temperature after V/I change-over circuit.Corresponding fast, the low-power consumption of this design, reduce the interference that transmission line is subject to noise simultaneously, improve isolation effect and improve the stability of device.

Above-mentioned thermal resistance isolating safety grid, described power circuit comprises power input part, transformer and power output part.Described power circuit exports constant voltage supply integrated circuit and modules by transformer is stable, and power supply can adjust flexibly according to budget.

Above-mentioned thermal resistance isolating safety grid, described signal isolation module adopts optical coupling isolator or magnetic coupling digital isolator.Optical coupling isolator or magnetic coupling digital isolator can be selected as required to signal isolation module.Wherein optical coupling isolator product category is various, low price.Its signal one-way transmission, input end and output terminal fully achieve electrical isolation isolates, and outputs signal on input end without impact, and antijamming capability is strong, contactless, long service life.And magnetic coupling digital isolator is low in energy consumption, digital isolator under low frequency condition a use photo-coupler power 1%; Under the highest transfer rate condition of photo-coupler, it uses about 20% of photo-coupler power, reduces power and it can be made to improve reliability.

Further, above-mentioned thermal resistance isolating safety grid, described central processing unit is ARMCortexM7 or STM32 processor.Can choice for use ARMCortexM7 or STM32 processor as required, arithmetic speed is improved, and be integrated with the function of internal electric source reset and detection of power loss and multiple peripheral hardware, thus make the structure of isolating safety grid more simple, reduce its production cost.

Technique scheme can be found out, the utility model has following beneficial effect: thermal resistance isolating safety grid described in the utility model, and structure is simple, and production cost is low, and good temp characteristic, response are fast, low-power consumption, isolation effect is good and reliability is high.

Accompanying drawing explanation

Fig. 1 is the schematic block circuit diagram of thermal resistance isolating safety grid described in the utility model;

Fig. 2 is the theory diagram of the power circuit of thermal resistance isolating safety grid described in the utility model.

Embodiment

Below in conjunction with the drawings and specific embodiments, illustrate the utility model further.

Thermal resistance isolating safety grid as shown in Figure 1, comprises power circuit, technological processing for explosion protection feature module, resistive voltage modular converter, filter and amplification module, signal acquisition module, central processing unit, signal isolation module, resistance capacitance integrating circuit, Voltage to current transducer module, output circuit; The output terminal of described power circuit connects the input end of technological processing for explosion protection feature module, central processing unit and signal isolation module respectively; The output terminal contact resistance voltage transformation module input end of described technological processing for explosion protection feature module; The output terminal of described resistive voltage modular converter connects the input end of filter and amplification module; The input end of the output terminal connection signal acquisition module of described filter and amplification module; The output terminal of described signal acquisition module connects the input end of central processing unit; The input end of the output terminal connection signal isolation module of described central processing unit; The input end of the output terminal contact resistance capacitance integral circuit of described signal isolation module; The output terminal of described resistance capacitance integrating circuit connects the input end of Voltage to current transducer module; The output terminal of described Voltage to current transducer module connects output circuit.

As shown in Figure 2, power circuit is that safety barrier is powered, and by power input part, transformer and power output part, described power output part comprises the output of 5V voltage, 3.3V voltage exports and other voltage exports, and exports constant voltage supply integrated circuit and modules.Signal isolation module can adopt optical coupling isolator or magnetic coupling digital isolator, and the present embodiment signal isolation module adopts ADUM7643 four-way magnetic coupling digital isolator, and its volume is little, and stability, real-time are good.Central processing unit adopts ARMCortexM7 processor, it has high-performance leading in the industry and system interface flexibly, have employed low energy consumption CPU design, a large amount of data can be processed, higher than conventional single-chip microcomputer scheme arithmetic speed, and be integrated with the function of internal electric source reset and detection of power loss and multiple peripheral hardware.

The above is only preferred implementation of the present utility model; it should be pointed out that for those skilled in the art, under the prerequisite not departing from the utility model principle; can also make some improvement, these improvement also should be considered as protection domain of the present utility model.

Claims (4)

1. a thermal resistance isolating safety grid, is characterized in that: comprise power circuit, technological processing for explosion protection feature module, resistive voltage modular converter, filter and amplification module, signal acquisition module, central processing unit, signal isolation module, resistance capacitance integrating circuit, Voltage to current transducer module, output circuit; The output terminal of described power circuit connects the input end of technological processing for explosion protection feature module, central processing unit and signal isolation module respectively; The output terminal contact resistance voltage transformation module input end of described technological processing for explosion protection feature module; The output terminal of described resistive voltage modular converter connects the input end of filter and amplification module; The input end of the output terminal connection signal acquisition module of described filter and amplification module; The output terminal of described signal acquisition module connects the input end of central processing unit; The input end of the output terminal connection signal isolation module of described central processing unit; The input end of the output terminal contact resistance capacitance integral circuit of described signal isolation module; The output terminal of described resistance capacitance integrating circuit connects the input end of Voltage to current transducer module; The output terminal of described Voltage to current transducer module connects output circuit.

2. thermal resistance isolating safety grid according to claim 1, is characterized in that: described power circuit comprises power input part, transformer and power output part.

3. thermal resistance isolating safety grid according to claim 1 and 2, is characterized in that: described signal isolation module adopts optical coupling isolator or magnetic coupling digital isolator.

4. thermal resistance isolating safety grid according to claim 1, is characterized in that: described central processing unit is ARMCortexM7 or STM32 processor.