CN201893771U

CN201893771U - Universal interface circuit for discrete magnitude acquisition of airborne equipment

Info

Publication number: CN201893771U
Application number: CN2010206199016U
Authority: CN
Inventors: 田军
Original assignee: Shaanxi Qianshan Avionics Co Ltd
Current assignee: Shaanxi Qianshan Avionics Co Ltd
Priority date: 2010-11-19
Filing date: 2010-11-19
Publication date: 2011-07-06
Anticipated expiration: 2020-11-19

Abstract

The utility model belongs to electronic technology, and particularly discloses an interface circuit for discrete magnitude acquisition of airborne equipment. The circuit comprises four comparators, an analog switch, a voltage stabilizing diode and resistors, as well as two control input lines and two data output lines, wherein the second comparator N2 and the third comparator N3 which are connected with the output lines serve as voltage comparators; and the first comparator N1 and the fourth comparator N4 which are connected with the control lines serve as digital switches. In the utility model, an interface between a discrete magnitude signal and a digital circuit is formed by the comparators and the resistors; as the interface circuit is controlled by the digital circuit, the combination of a plurality of discrete magnitudes can be distinguished; the interface circuit has the characteristics of strong anti-interference ability and high signal level discrimination; and as the pull-up and pull-down of signals, and the discrimination threshold are settable, the interface circuit adapts to the acquisition of various signal combinations to show the flexible configuration, and can effectively increase the number of acquisition channels and improve the acquisition accuracy.

Description

The general acquisition interface circuit of airborne equipment discrete magnitude

Technical field

The utility model belongs to the electronic technology class, relates to the general acquisition interface circuit of a kind of airborne equipment discrete magnitude.

Background technology

At the collection of common discrete magnitude signal 27V/ open circuit, 27V/0V, 0V/ open circuit, 5V/0V signal on the airborne equipment, acquisition mode generally has two kinds at present: a kind of is at concrete signal combination, adopts special-purpose circuit form collection; Another kind is based on configurable mode and gathers, and promptly adopts general interface circuit to gather to various signal combination.

First kind of acquisition mode interface is simple, and interface features is fixed, in case signal type changes, needs to revise interface circuit, and be cumbersome.But its signal level discrimination height is not allowed to be subject to disturb.

Second kind of acquisition mode interface is simple, but at the collection of open circuit signaling, has signal level and distinguishes not obviously, and the shortcoming of being disturbed easily during identification causes gathering unstable easily.But its configurable characteristics are more flexible.

Summary of the invention

The purpose of this utility model is: the utility model provides the general acquisition interface circuit of airborne equipment discrete magnitude of a kind of signal level discrimination height, flexible configuration.

The technical solution of the utility model is: the general acquisition interface circuit of a kind of airborne equipment discrete magnitude, it comprises four comparators, analog switch, voltage stabilizing didoe and resistance and two control incoming line and two single data output lines, second comparator N2 that wherein is connected with output line and the 3rd comparator N3 are when voltage comparator usefulness, and first comparator N1 that is connected with control line and the 4th comparator N4 are as digital switch.

Described resistance comprises first resistance R 1, second resistance R 2, the 3rd resistance R 3, the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, the 7th resistance R 7.

The in-phase input end of the described first comparator N1 meets Vref, out-phase input termination control line, and its output one tunnel is connected to VDD after second resistance R 2, be connected to the in-phase input end of the second comparator N2 after another Lu Jingdi three resistance R 3; The in-phase input end of the described second comparator N2 directly links to each other with the in-phase input end of analog switch with the 3rd comparator N3 respectively, and be connected to VDD through the 4th resistance R 4, the out-phase input that is connected to the 3rd comparator N3 through the 5th resistance R 5 links to each other, and is connected to the output of the 4th comparator through the 7th resistance R 7; The output of described second comparator N2 and the 3rd comparator N3 is connected DOL Data Output Line, and the out-phase input of the 3rd comparator N3 is ground connection after the 6th resistance R 6, and the in-phase input end of the 4th comparator N4 meets Vref, out-phase input termination control line; Described analog switch links to each other with first resistance R 1, and behind voltage stabilizing didoe D1 ground connection.

The described first comparator N1 ground connection, it is connected between resistance R 2, the R3, and is provided with voltage stabilizing didoe river artifical resistance between the resistance R 1, R3.

The first comparator N1 and the 4th comparator N4 can be comparator, digital circuit, triode or the field effect transistor of relay, OC output as digital switch.

Technique effect of the present utility model: the general acquisition interface circuit of the utility model airborne equipment discrete magnitude has constituted a kind of interface circuit that can conveniently differentiate multiple discrete magnitude combination by comparator and resistance.Have the advantages that antijamming capability is strong, the signal level discrimination is high, and the collection that enables to adapt to multiple signal combination of setting of drop-down and discrimination threshold it on, embodied the characteristics of its flexible configuration.In the collection of multichannel discrete magnitude signal, use the collocation of this circuit and analog switching circuit, can under the certain situation of printed board area, effectively improve acquisition channel number and collection accuracy (anti-interference).

Description of drawings

Fig. 1 is the circuit diagram of general acquisition interface circuit one better embodiment of the utility model airborne equipment discrete magnitude.

Drop-down equivalent circuit diagram on Fig. 2.

Embodiment

The utility model is described in further detail below by embodiment:

See also Fig. 1, it is the circuit diagram of general acquisition interface circuit one better embodiment of the utility model airborne equipment discrete magnitude.

The general acquisition interface circuit of the utility model airborne equipment discrete magnitude comprises four comparators, seven resistance, a voltage stabilizing didoe and an analog switch.Wherein, described four comparators are respectively the first comparator N1, the second comparator N2, the 3rd comparator N3 and the 4th comparator N4, and described seven resistance are respectively first resistance R 1, second resistance R 2, the 3rd resistance R 3, the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, the 7th resistance R 7.The in-phase input end of the described first comparator N1 connects Vref (control signal compare threshold, greater than the control signal low level, less than the control signal high level), out-phase input termination control line, its output one tunnel is connected to VDD (analog power voltage) after second resistance R 2, be connected to the in-phase input end of the second comparator N2 after another Lu Jingdi three resistance R 3.Simultaneously, the in-phase input end of the described second comparator N2 directly links to each other with the in-phase input end of analog switch with the 3rd comparator N3 respectively, and be connected to VDD through the 4th resistance R 4, the out-phase input that is connected to the 3rd comparator N3 through the 5th resistance R 5 links to each other, and is connected to the output of the 4th comparator through the 7th resistance R 7.In addition, the output of described second comparator N2 and the 3rd comparator N3 is connected DOL Data Output Line, and the out-phase input of the 3rd comparator N3 is ground connection after the 6th resistance R 6, and the in-phase input end of the 4th comparator N4 meets Vref, out-phase input termination control line.Described analog switch (using during multichannel collecting) links to each other with first resistance R 1, and behind voltage stabilizing didoe D1 ground connection.Input signal links to each other with R1.

The general acquisition interface circuit of the utility model airborne equipment discrete magnitude uses four comparators, analog switch (using in the multichannel collecting), voltage stabilizing didoe and resistance to realize drawing with drop-down on the resistance of signal input, and the setting of compare threshold level, and the subsequent acquisition circuit is a digital interface, has two control incoming lines and two single data output lines.Second comparator N2 that wherein is connected with output line and the 3rd comparator N3 are when voltage comparator usefulness, first comparator N1 that is connected with control line and the 4th comparator N4 are as digital switch, comparator can use the gate circuit equivalent substitution of transistor, relay and open-drain or open collector output as the use of switch herein.

Wherein, N1～N4 is comparator or other switching device (relay, transistor etc.) of OC (open collector) output, and its power supply negative terminal voltage is 0V, and power positive end voltage is VDD.Can by the first comparator N1 realize signal on draw with drop-down.Can realize the setting of comparative level by the 4th comparator N4.

When the general acquisition interface circuit of the utility model airborne equipment discrete magnitude was imported TTL low level (less than Vref) by CTRL0, the first comparator N1 exported vacant state, and signal draws mode on being, its equivalent electric circuit is shown in Fig. 2 .a.Under this mode, open circuit input by on move VDD (the in-phase input end voltage of threshold value comparator N2, N3) to, be fit to gather " 0V " effectively signal combination, as 27V/0V, open circuit/0V, 5V/0V.

During by CTRL0 input TTL high level (or greater than level greater than Vref), the first comparator N1 exports ground state, and signal is a pull-down pattern, shown in Fig. 2 .b.Under this mode, the open circuit input is pulled down to 0V (the in-phase input end voltage of threshold value comparator N2, N3), is fit to gather the combination of the effective signal of high level, as 0V/27V, open circuit/27V, 0V/5V.

During by CTRL1 input TTL low level (less than Vref), upper limit threshold and lower threshold are provided with by R4, R5, R6 series circuit dividing potential drop.

During by CTRL1 input TTL high level (or greater than level greater than Vref), R5 is in parallel with R7 after connecting with R6, connects with R4 then, in this case, upper limit threshold and lower threshold can be reduced (than the situation of CTRL1 input low level).

By the value of R4～R7 is set, can adjust threshold value flexibly.In the following differentiation, the upper limit threshold when setting the CTRL1 input low level is 7V, and lower threshold is 3V; Upper limit threshold when setting the CTRL1 input high level is 3.5V, and lower threshold is 1.5V.

Choosing R1 is 150k, and R2 is 150k, and R3 is 750k.Then can obtain following result.

Annotate: CTRL0=1 is expressed as high level in the table, and CTRL0=0 is expressed as low level.

According to the result in the table, the decision procedure that obtains various switching value combinations is as follows:

1,27V/0V or 27V/ open circuit, 27V is effective: CTRL0=1 is set, CTRL1=0.When COMP0=1 and COMP1=1, represent the current 27V input that is; When COMP0=0 and COMP1=0, represent current be 0V input or open circuit input; When COMP0=0 and COMP1=1, be transition state, keep last judged result; When COMP0=1 and COMP1=0, the indication circuit fault.

2,27V/0V or 0V/ open circuit, 0V is effective: CTRL0=0 is set, CTRL1=0.When COMP0=1 and COMP1=1, represent that current is 27V or open circuit input; When COMP0=0 and COMP1=0, represent the current 0V input input that is; When COMP0=0 and COMP1=1, be transition state, keep last judged result; When COMP0=1 and COMP1=0, the indication circuit fault.

3,27V/ open circuit or 0V/ open circuit, open circuit is effective: CTRL1=0 is set.If when CTRL0=1, COMP0=1 and COMP1=1, and when CTRL0=0, COMP0=0 and COMP1=0 then are judged as open circuit.

4,5V/0V signal: CTRL0=1 is set, CTRL1=1.When COMP0=1 and COMP1=1, represent the current 5V input that is; When COMP0=0 and COMP1=0, represent the current 0V input that is; When COMP0=0 and COMP1=1, be transition state, keep last judged result; When COMP0=1 and COMP1=0, the indication circuit fault.

The utility model can be configured to by one group and draws or drop-down circuit has realized that the state of open circuit signaling determines, making its corresponding equivalent level is VDD or 0V, make two kinds of discrete signals of input draw to such an extent that open most as much as possible at the voltage of threshold value comparator N2 and N3 input, improve the discrimination of signal, thereby strengthened the anti-interference that signal is input as open-circuit condition interface circuit of following time.By the setting of judging circuit upper limit compare threshold and lower limit compare threshold, can cooperate software to realize that the hysteresis of signal compares, and has also improved anti-interference.For the combination sort of varying level, consider that its discrimination threshold has nothing in common with each other, adopted the mode of threshold circuit and connecting resistance to adjust compare threshold.This circuit has the advantages that antijamming capability is strong, the signal level discrimination is high, and the collection that enables to adapt to multiple signal combination of setting of drop-down and discrimination threshold it on, has embodied the characteristics of its flexible configuration.In the collection of multichannel discrete magnitude signal, use the collocation of this circuit and analog switching circuit, can under the certain situation of printed board area, effectively improve acquisition channel number and collection accuracy.

Claims

1. general acquisition interface circuit of airborne equipment discrete magnitude, it is characterized in that: comprise four comparators, analog switch, voltage stabilizing didoe and resistance and two control incoming line and two single data output lines, second comparator N2 that wherein is connected with output line and the 3rd comparator N3 are when voltage comparator usefulness, and first comparator N1 that is connected with control line and the 4th comparator N4 are as digital switch.

2. the general acquisition interface circuit of airborne equipment discrete magnitude according to claim 1 is characterized in that: resistance comprises first resistance R 1, second resistance R 2, the 3rd resistance R 3, the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, the 7th resistance R 7.

3. the general acquisition interface circuit of airborne equipment discrete magnitude according to claim 2, it is characterized in that: the in-phase input end of the described first comparator N1 meets Vref, out-phase input termination control line, its output one tunnel is connected to VDD after second resistance R 2, be connected to the in-phase input end of the second comparator N2 after another Lu Jingdi three resistance R 3; The in-phase input end of the described second comparator N2 directly links to each other with the in-phase input end of analog switch with the 3rd comparator N3 respectively, and be connected to VDD through the 4th resistance R 4, the out-phase input that is connected to the 3rd comparator N3 through the 5th resistance R 5 links to each other, and is connected to the output of the 4th comparator through the 7th resistance R 7; The output of described second comparator N2 and the 3rd comparator N3 is connected DOL Data Output Line, and the out-phase input of the 3rd comparator N3 is ground connection after the 6th resistance R 6, and the in-phase input end of the 4th comparator N4 meets Vref, out-phase input termination control line; Described analog switch links to each other with first resistance R 1, and behind voltage stabilizing didoe D1 ground connection.

4. the general acquisition interface circuit of airborne equipment discrete magnitude according to claim 2 is characterized in that: the described first comparator N1 ground connection, it is connected between resistance R 2, the R3, and is provided with voltage stabilizing didoe river artifical resistance between the resistance R 1, R3.

5. according to claim 3 or the general acquisition interface circuit of 4 described airborne equipment discrete magnitudes, it is characterized in that: the first comparator N1 and the 4th comparator N4 be as digital switch, can be the comparator of relay, OC output or digital circuit, triode, field effect transistor.