CN103575969B - A kind of device and method measuring the voltage of communication line, resistance - Google Patents

Abstract

The present invention relates to measure the voltage of communication line, the device and method of resistance.This device includes the power circuit for power supply, the first contact, the second contact, sampling resistor R_s, switching circuit, test voltage produce circuit and data processing circuit；Test voltage produces one end of circuit by sampling resistor R_sBeing connected with the first contact, test voltage produces the other end and the connection of the second contact of circuit；Described switching circuit, for controlling A line and the switching of B line of the first contact, the second contact and test line；Described test voltage produces circuit, is used for producing two-way VDCT volts ,direct-current ,test；Data processing circuit is used for being calculated resistance to earth, voltage-to-ground, line resistance and voltage between lines.The present invention once-through operation just can obtain the value of resistance to earth, voltage-to-ground and line resistance simultaneously, easy to operate, measures efficiency high.

Description

A kind of device and method measuring the voltage of communication line, resistance

Technical field

The present invention relates to measurement technology, be specifically related to a kind of device and method measuring the voltage of communication line, resistance.

Background technology

At present, voltage measurement in digital multimeter (DMM) and resistance measurement belong to the technology of comparative maturity, method of testing And circuit is more.And in mechanics of communication, need the voltage to communication line (telephone wire, netting twine etc.), resistance to measure, logical News circuit is to occur in pairs, including A line and B line, with DC voltage on communication line, and can not be same by digital multimeter Time measure the resistance to earth on circuit, voltage-to-ground and line resistance, need manual operation more than at least 4 times, cumbersome.

Summary of the invention

It is an object of the invention to propose a kind of device and method measuring the voltage of communication line, resistance, it can solve The problem that can not simultaneously measure resistance to earth, voltage-to-ground and line resistance.

In order to achieve the above object, the technical solution adopted in the present invention is as follows:

A kind of device measuring the voltage of communication line, resistance, it include for power supply power circuit, the first contact, Second contact, sampling resistor R_s, switching circuit, test voltage produce circuit and data processing circuit；Test voltage produces circuit One end by sampling resistor R_sBeing connected with the first contact, test voltage produces the other end and the connection of the second contact of circuit；

Described switching circuit, for controlling A line and the switching of B line of the first contact, the second contact and test line, so that Connection status is connected with A line in the first contact and the second contact and A line grounding connection, the first contact are connected with B line and second touches The three that point is connected with A line with B line grounding connection, the first contact and the second contact is connected with B line switches over；

Described test voltage produces circuit, is used for producing two-way VDCT volts ,direct-current ,test V_s1And V_s2, wherein, V_s1And V_s2It is Test voltage produces circuit and sampling resistor R_sThe voltage connected between node and the second contact；

Described data processing circuit, is used for obtaining V_s1、V_s2、V_rs1And V_rs2, and calculate according to formula (3), obtain R_x And V_x, wherein, V_rs1For loading V_s1Time sampling resistor R_sOn voltage, V_rs2For loading V_s2Time sampling resistor R_sOn electricity Pressure；

$\left\{\begin{array}{c}{V}_x=\frac{V_{\mathrm{rs}1}(V_{s2}-V_{\mathrm{rs}2})-V_{\mathrm{rs}2}(V_{s1}-V_{\mathrm{rs}1})}{V_{\mathrm{rs}1}-V_{\mathrm{rs}2}}\\ R_x=\frac{R_s(V_{s2}-V_{s1}-V_{\mathrm{rs}2}+V_{\mathrm{rs}1})}{V_{\mathrm{rs}2}-V_{\mathrm{rs}1}}\end{array}\right.---\left(3\right);$

When the first contact be connected with A line and the second contact with A line grounding connection time, R_x=R_ag, V_x=V_ag；

When the first contact be connected with B line and the second contact with B line grounding connection time, R_x=R_bg, V_x=V_bg；

When the first contact is connected with A line and the second contact is connected with B line, R_x=R_ab, V_x=V_ab；

Wherein, R_agFor A line resistance to earth, R_bgFor B line resistance to earth, R_abFor the line resistance between A line and B line, V_agFor A line-to-earth voltage, V_bgFor B line-to-earth voltage, V_abFor the voltage between lines between A line and B line.

Preferably, in order to protection device is not damaged by, described data processing circuit includes that the logic being linked in sequence successively declines Subtract device, gain controller, A/D converter and CPU；Described switching circuit is additionally operable to control the break-make of described logic attenuator, when When the amplitude of the voltage of test line exceedes predetermined value, described switching circuit control described logic attenuator access test line with Between the input of gain controller；When the amplitude of the voltage of test line is less than or equal to predetermined value, described switching circuit Control the short circuit of described logic attenuator.

Preferably, described switching circuit is relay group or FPGA or CPLD.

Preferably, for the scope of application and the application scenarios of expansion instrument, V_s1And V_s2It is negative voltage.

The invention also discloses a kind of method measuring the voltage of communication line, resistance, it comprises the following steps:

A, the A line being controlled the first contact, the second contact and test line by switching circuit and the switching of B line, so that even The state that connects is connected with A line in the first contact and the second contact is connected and the second contact with B line with A line grounding connection, the first contact It is connected with A line with B line grounding connection, the first contact and three that the second contact is connected with B line switches over；Same switch Time, a test voltage produces circuit and produces two-way VDCT volts ,direct-current ,test V_s1And V_s2, V_s1And V_s2Be test voltage produce circuit with Sampling resistor R_sThe voltage connected between node and the second contact；Wherein, test voltage produces one end of circuit by sampling Resistance R_sBeing connected with the first contact, test voltage produces the other end and the connection of the second contact of circuit；

B, data processing circuit obtain V_s1、V_s2、V_rs1And V_rs2, and calculate according to formula (3), obtain R_xAnd V_x, its In, V_rs1For loading V_s1Time sampling resistor R_sOn voltage, V_rs2For loading V_s2Time sampling resistor R_sOn voltage；

$\left\{\begin{array}{c}{V}_x=\frac{V_{\mathrm{rs}1}(V_{s2}-V_{\mathrm{rs}2})-V_{\mathrm{rs}2}(V_{s1}-V_{\mathrm{rs}1})}{V_{\mathrm{rs}1}-V_{\mathrm{rs}2}}\\ R_x=\frac{R_s(V_{s2}-V_{s1}-V_{\mathrm{rs}2}+V_{\mathrm{rs}1})}{V_{\mathrm{rs}2}-V_{\mathrm{rs}1}}\end{array}\right.---\left(3\right);$

C, output result: when the first contact is connected with A line and the second contact and during A line grounding connection, R_x=R_ag, V_x=V_ag； When the first contact be connected with B line and the second contact with B line grounding connection time, R_x=R_bg, V_x=V_bg；When the first contact is connected with A line And second contact when being connected with B line, R_x=R_ab, V_x=V_ab；Wherein, R_agFor A line resistance to earth, R_bgFor B line resistance to earth, R_abFor A Line resistance between line and B line, V_agFor A line-to-earth voltage, V_bgFor B line-to-earth voltage, V_abFor between the line between A line and B line Voltage.

Preferably, described data processing circuit includes that the logic attenuator being linked in sequence successively, gain controller, A/D turn Parallel operation and CPU；Step A also has following process: when the amplitude of the voltage of test line exceedes predetermined value, described switching electricity Road controls described logic attenuator and accesses between test line and the input of gain controller, makes data processing circuit with tested Circuit disconnects；When the amplitude of the voltage of test line is less than or equal to predetermined value, described switching circuit controls described logic and declines Subtract device short circuit, make data processing circuit turn on test line.

Preferably, described switching circuit is relay group or FPGA or CPLD.

Preferably, V_s1And V_s2It is negative voltage.

There is advantages that

After access communications circuit, once-through operation just can obtain the value of resistance to earth, voltage-to-ground and line resistance simultaneously, behaviour Facilitate, measure efficiency high.

Accompanying drawing explanation

Fig. 1 is the structural representation of the device measuring the voltage of communication line, resistance of present pre-ferred embodiments；

Fig. 2 be present pre-ferred embodiments measure the voltage of communication line, resistance device measure A line over the ground electricity Measurement model figure when resistance, voltage-to-ground；

Fig. 3 be present pre-ferred embodiments measure the voltage of communication line, resistance device measure B line over the ground electricity Measurement model figure when resistance, voltage-to-ground；

Fig. 4 be present pre-ferred embodiments measure the voltage of communication line, resistance device measure A line and B line it Between line resistance, voltage between lines time measurement model figure；

Fig. 5 is the flow chart of the method measuring the voltage of communication line, resistance of present pre-ferred embodiments.

Detailed description of the invention

Below, in conjunction with accompanying drawing and detailed description of the invention, the present invention is described further.

As it is shown in figure 1, a kind of device measuring the voltage of communication line, resistance, it include the power circuit for power supply, First the 1, second contact 2, contact, sampling resistor R_s, switching circuit, test voltage produce circuit and data processing circuit；Test electricity Pressure produces one end (such as: positive terminal) of circuit by sampling resistor R_sBeing connected with the first contact 1, test voltage produces the another of circuit (such as: negative pole end) is connected with the second contact 2 in one end.Logic attenuator that described data processing circuit includes being linked in sequence successively, Gain controller, A/D converter and CPU.Gain controller is for regulating the amplitude of signal, and A/D converter is for believing simulation Number being converted to digital signal, CPU is used for data sampling and calculating.

Described switching circuit, for controlling A line and the switching of B line of the 1, second contact, the first contact 2 and test line, with Make connection status be connected with A line in the first contact 1 and the second contact 2 and A line grounding connection, the first contact 1 are connected with B line and The three that two contacts 2 and B line grounding connection, the first contact 1 are connected with A line and the second contact 2 is connected with B line switches over； And for controlling the break-make of described logic attenuator, when the amplitude of the voltage of test line exceedes predetermined value (such as 15V), institute State switching circuit to control between described logic attenuator access test line and the input of gain controller；When test line When the amplitude of voltage is less than or equal to predetermined value, described switching circuit controls the short circuit of described logic attenuator.Cutting of the present embodiment Changing circuit can use relay group or FPGA or CPLD to realize.

Described test voltage produces circuit, is used for producing two-way VDCT volts ,direct-current ,test V_s1And V_s2, wherein, V_s1And V_s2It is Test voltage produces circuit and sampling resistor R_sThe voltage connected between node and the second contact.In order to wide adaptability some, Test voltage produces circuit and selects negative pressure source to be preferred, i.e. V_s1And V_s2It is negative voltage.

Described data processing circuit, is used for obtaining V_s1、V_s2、V_rs1And V_rs2, and calculate according to formula (3), obtain R_x And V_x, wherein, V_rs1For loading V_s1Time sampling resistor R_sOn voltage, V_rs2For loading V_s2Time sampling resistor R_sOn electricity Pressure；

$\left\{\begin{array}{c}{V}_x=\frac{V_{\mathrm{rs}1}(V_{s2}-V_{\mathrm{rs}2})-V_{\mathrm{rs}2}(V_{s1}-V_{\mathrm{rs}1})}{V_{\mathrm{rs}1}-V_{\mathrm{rs}2}}\\ R_x=\frac{R_s(V_{s2}-V_{s1}-V_{\mathrm{rs}2}+V_{\mathrm{rs}1})}{V_{\mathrm{rs}2}-V_{\mathrm{rs}1}}\end{array}\right.---\left(3\right);$

When the first contact 1 be connected with A line and the second contact 2 with A line grounding connection time, R_x=R_ag, V_x=V_ag；When the first contact 1 be connected with B line and the second contact 2 with B line grounding connection time, R_x=R_bg, V_x=V_bg；When the first contact 1 is connected with A line and second touches When point 2 is connected with B line, R_x=R_ab, V_x=V_ab；Wherein, R_agFor A line resistance to earth, R_bgFor B line resistance to earth, R_abFor A line and B line Between line resistance, V_agFor A line-to-earth voltage, V_bgFor B line-to-earth voltage, V_abFor the voltage between lines between A line and B line.

The principle of the present embodiment, refers to Fig. 2 for convenience of description, for measuring the resistance to earth R of A line_agAnd voltage-to-ground V_agMeasurement model.By switching circuit, the first contact 1 is made to be connected with A line, the second contact 2 and A line grounding connection (i.e. second Contact 2 is connected with A line by ground wire), V_sThe known DC producing circuit output for test voltage measures voltage, V_rsFor output V_sTime Sampling resistor R_sThe D/C voltage of upper correspondence, V_mIt is the voltage between the first contact 1 and the second contact 2.

Owing to there being R_agAnd V_agIt is two unknown numbers, it is therefore desirable to measure twice by two different D/C voltage, according to wearing dimension South theorem obtains two independent equations, as shown in Equation (1).

$\left\{\begin{array}{c}{V}_{s1}=V_{\mathrm{rs}1}+\frac{V_{\mathrm{rs}1}}{R_s}\×R_{\mathrm{ag}}+V_{\mathrm{ag}}\\ V_{s2}=V_{\mathrm{rs}2}+\frac{V_{\mathrm{rs}2}}{R_s}\×R_{\mathrm{ag}}+V_{\mathrm{ag}}\end{array}\right.---\left(1\right)$

V in formula_s1、V_s2It is respectively test voltage and produces known 2 DC measurement voltage of circuit output, V_rs1、V_rs2Respectively For output V_s1、V_s2Time sampling resistor R_sThe D/C voltage of upper correspondence, R_agFor resistance to be measured, V_agFor voltage to be measured.V_m1、V_m2Point Wei not export V_s1、V_s2Time, the voltage between the first contact 1 and the second contact 2, then formula (1) can obtain after arranging:

$\left\{\begin{array}{c}{V}_{\mathrm{ag}}=\frac{V_{\mathrm{rs}1}{V}_{m2}-V_{\mathrm{rs}2}{V}_{m1}}{V_{\mathrm{rs}1}-V_{\mathrm{rs}2}}\\ R_{\mathrm{ag}}=\frac{R_s(V_{m2}-V_{m1})}{V_{\mathrm{rs}2}-V_{\mathrm{rs}1}}\end{array}\right.---\left(2\right)$

According to circuit theory:

V_m2=V_s2-V_rs2

V_m1=V_s1-V_rs1

Above equation is replaced and solves:

$\left\{\begin{array}{c}{V}_{\mathrm{ag}}=\frac{V_{\mathrm{rs}1}(V_{s2}-V_{\mathrm{rs}2})-V_{\mathrm{rs}2}(V_{s1}-V_{\mathrm{rs}1})}{V_{\mathrm{rs}1}-V_{\mathrm{rs}2}}\\ R_{\mathrm{ag}}=\frac{R_s(V_{s2}-V_{s1}-V_{\mathrm{rs}2}+V_{\mathrm{rs}1})}{V_{\mathrm{rs}2}-V_{\mathrm{rs}1}}\end{array}\right.---\left(3\right)$

In like manner, refer to Fig. 3, measure the resistance to earth R of B line_bgWith voltage-to-ground V_bgPrinciple identical with Fig. 2.If it is logical Cross switching circuit, make the first contact 1 be connected with B line, the second contact 2 and B line grounding connection, i.e. available required measurement ginseng Number.

In like manner, see Fig. 4, measure the line resistance R between A line and B line_abWith voltage between lines V_abPrinciple identical with Fig. 2. As long as by switching circuit, making the first contact 1 be connected with A line, the second contact 2 is connected with B line, i.e. available required measurement ginseng Number.

It should be noted that according to the difference of connection status, V_rs1And V_rs2Value be also different.

The present embodiment also disclose a kind of use the voltage of above-mentioned measurement communication line, resistance device to communication line The method that voltage, resistance measure, its flow chart is as it is shown in figure 5, comprise the following steps:

A, the A line being controlled the first contact, the second contact and test line by switching circuit and the switching of B line, so that even The state that connects is connected with A line in the first contact and the second contact is connected and the second contact with B line with A line grounding connection, the first contact It is connected with A line with B line grounding connection, the first contact and three that the second contact is connected with B line switches over；Same switch Time, a test voltage produces circuit and produces two-way VDCT volts ,direct-current ,test V_s1And V_s2, V_s1And V_s2Be test voltage produce circuit with Sampling resistor R_sThe voltage connected between node and the second contact；Wherein, test voltage produces one end of circuit by sampling Resistance R_sBeing connected with the first contact, test voltage produces the other end and the connection of the second contact of circuit；

B, data processing circuit obtain V_s1、V_s2、V_rs1And V_rs2, and calculate according to formula (3), obtain R_xAnd V_x, its In, V_rs1For loading V_s1Time sampling resistor R_sOn voltage, V_rs2For loading V_s2Time sampling resistor R_sOn voltage；

$\left\{\begin{array}{c}{V}_x=\frac{V_{\mathrm{rs}1}(V_{s2}-V_{\mathrm{rs}2})-V_{\mathrm{rs}2}(V_{s1}-V_{\mathrm{rs}1})}{V_{\mathrm{rs}1}-V_{\mathrm{rs}2}}\\ R_x=\frac{R_s(V_{s2}-V_{s1}-V_{\mathrm{rs}2}+V_{\mathrm{rs}1})}{V_{\mathrm{rs}2}-V_{\mathrm{rs}1}}\end{array}\right.---\left(3\right);$

C, output result: when the first contact is connected with A line and the second contact and during A line grounding connection, R_x=R_ag, V_x=V_ag； When the first contact be connected with B line and the second contact with B line grounding connection time, R_x=R_bg, V_x=V_bg；When the first contact is connected with A line And second contact when being connected with B line, R_x=R_ab, V_x=V_ab；Wherein, R_agFor A line resistance to earth, R_bgFor B line resistance to earth, R_abFor A Line resistance between line and B line, V_agFor A line-to-earth voltage, V_bgFor B line-to-earth voltage, V_abFor between the line between A line and B line Voltage.

In order to avoid the present embodiment device due to communication line voltage excessive and damage, step A also has following place Reason: when the amplitude of the voltage of test line exceedes predetermined value, described switching circuit controls described logic attenuator and accesses tested Between circuit and the input of gain controller, making data processing circuit disconnect with test line, measurement terminates；Work as test line Voltage amplitude less than or equal to predetermined value time, described switching circuit control described logic attenuator short circuit, make data process Circuit turns on test line, and measurement starts.

For a person skilled in the art, can technical scheme as described above and design, make other each Plant corresponding change and deformation, and all these changes and deforms the protection model that all should belong to the claims in the present invention Within enclosing.

Claims (8)

1. measuring a device for the voltage of communication line, resistance, it includes the power circuit for power supply, it is characterised in that Also include the first contact, the second contact, sampling resistor R_s, switching circuit, test voltage produce circuit and data processing circuit；Survey One end of examination voltage generation circuit is by sampling resistor R_sBeing connected with the first contact, test voltage produces the other end and the of circuit Two contacts connect；

Described switching circuit, for controlling A line and the switching of B line of the first contact, the second contact and test line, so that connecting State is connected with A line in the first contact and the second contact and A line grounding connection, the first contact are connected with B line and the second contact and B The three that line grounding connection, the first contact are connected with A line and the second contact is connected with B line switches over；

Described test voltage produces circuit, is used for producing two-way VDCT volts ,direct-current ,test V_s1And V_s2, wherein, V_s1And V_s2It is test Voltage generation circuit and sampling resistor R_sThe voltage connected between node and the second contact；

Described data processing circuit, is used for obtaining V_s1、V_s2、V_rs1And V_rs2, and calculate according to formula (3), obtain R_xAnd V_x, Wherein, V_rs1For loading V_s1Time sampling resistor R_sOn voltage, V_rs2For loading V_s2Time sampling resistor R_sOn voltage；

$\left\{\begin{array}{c}{V}_x=\frac{V_{\mathrm{rs}1}(V_{s2}-V_{\mathrm{rs}2})-V_{\mathrm{rs}2}(V_{s1}-V_{\mathrm{rs}1})}{V_{\mathrm{rs}1}-V_{\mathrm{rs}2}}\\ R_x=\frac{R_s(V_{s2}-V_{s1}-V_{\mathrm{rs}2}+V_{\mathrm{rs}1})}{V_{\mathrm{rs}2}-V_{\mathrm{rs}1}}\end{array}\right.---\left(3\right);$

When the first contact be connected with A line and the second contact with A line grounding connection time, R_x=R_ag, V_x=V_ag；

When the first contact be connected with B line and the second contact with B line grounding connection time, R_x=R_bg, V_x=V_bg；

When the first contact is connected with A line and the second contact is connected with B line, R_x=R_ab, Vx=V_ab；

Wherein, R_agFor A line resistance to earth, R_bgFor B line resistance to earth, R_abFor the line resistance between A line and B line, V_agFor A line Voltage-to-ground, V_bgFor B line-to-earth voltage, V_abFor the voltage between lines between A line and B line.

2. the measurement voltage of communication line, the device of resistance as claimed in claim 1, it is characterised in that described data process Circuit includes logic attenuator, gain controller, A/D converter and the CPU being linked in sequence successively；Described switching circuit is additionally operable to Controlling the break-make of described logic attenuator, when the amplitude of the voltage of test line exceedes predetermined value, described switching circuit controls Described logic attenuator accesses between test line and the input of gain controller；When the amplitude of the voltage of test line is less than Or during equal to predetermined value, described switching circuit controls the short circuit of described logic attenuator.

3. the measurement voltage of communication line, the device of resistance as claimed in claim 1, it is characterised in that described switching circuit For relay group or FPGA or CPLD.

4. the measurement voltage of communication line, the device of resistance as claimed in claim 1, it is characterised in that V_s1And V_s2It is negative Voltage.

5. the method measuring the voltage of communication line, resistance, it is characterised in that comprise the following steps:

A, the A line being controlled the first contact, the second contact and test line by switching circuit and the switching of B line, so that connecting shape State is connected with A line in the first contact and the second contact and A line grounding connection, the first contact are connected with B line and the second contact and B line The three that grounding connection, the first contact are connected with A line and the second contact is connected with B line switches over；While switching, one Test voltage produces circuit and produces two-way VDCT volts ,direct-current ,test V_s1And V_s2, V_s1And V_s2It is test voltage and produces circuit and sampling Resistance R_sThe voltage connected between node and the second contact；Wherein, test voltage produces one end of circuit by sampling resistor R_s Being connected with the first contact, test voltage produces the other end and the connection of the second contact of circuit；

B, data processing circuit obtain V_s1、V_s2、V_rs1And V_rs2, and calculate according to formula (3), obtain R_xAnd V_x, wherein, V_rs1For loading V_s1Time sampling resistor R_sOn voltage, V_rs2For loading V_s2Time sampling resistor R_sOn voltage；

$\left\{\begin{array}{c}{V}_x=\frac{V_{\mathrm{rs}1}(V_{s2}-V_{\mathrm{rs}2})-V_{\mathrm{rs}2}(V_{s1}-V_{\mathrm{rs}1})}{V_{\mathrm{rs}1}-V_{\mathrm{rs}2}}\\ R_x=\frac{R_s(V_{s2}-V_{s1}-V_{\mathrm{rs}2}+V_{\mathrm{rs}1})}{V_{\mathrm{rs}2}-V_{\mathrm{rs}1}}\end{array}\right.---\left(3\right);$

C, output result: when the first contact is connected with A line and the second contact and during A line grounding connection, R_x=R_ag, V_x=V_ag；When One contact is connected with B line and when the second contact and B line grounding connection, R_x=R_bg, V_x=V_bg；When the first contact is connected with A line and When two contacts are connected with B line, R_x=R_ab, V_x=V_ab；Wherein, R_agFor A line resistance to earth, R_bgFor B line resistance to earth, R_abFor A line with Line resistance between B line, V_agFor A line-to-earth voltage, V_bgFor B line-to-earth voltage, V_abFor electricity between the line between A line and B line Pressure.

6. the measurement voltage of communication line, the method for resistance as claimed in claim 5, it is characterised in that described data process Circuit includes logic attenuator, gain controller, A/D converter and the CPU being linked in sequence successively；Step A also have as follows Processing: when the amplitude of the voltage of test line exceedes predetermined value, described switching circuit controls described logic attenuator and accesses quilt Between survey line road and the input of gain controller, data processing circuit is made to disconnect with test line；Voltage when test line Amplitude less than or equal to predetermined value time, described switching circuit control described logic attenuator short circuit, make data processing circuit with Test line turns on.

7. the measurement voltage of communication line, the method for resistance as claimed in claim 5, it is characterised in that described switching circuit For relay group or FPGA or CPLD.

8. the measurement voltage of communication line, the method for resistance as claimed in claim 5, it is characterised in that V_s1And V_s2It is negative Voltage.