CN214750559U - Loop impedance detection device - Google Patents
Loop impedance detection device Download PDFInfo
- Publication number
- CN214750559U CN214750559U CN202120816414.7U CN202120816414U CN214750559U CN 214750559 U CN214750559 U CN 214750559U CN 202120816414 U CN202120816414 U CN 202120816414U CN 214750559 U CN214750559 U CN 214750559U
- Authority
- CN
- China
- Prior art keywords
- circuit
- loop
- voltage
- tested
- signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Measurement Of Resistance Or Impedance (AREA)
Abstract
The utility model provides a loop impedance detection device, include: the constant current source outputs current with a preset value, the amplifying circuit amplifies the voltage of the loop to be tested, the comparing circuit compares the voltage amplification signal with a reference voltage and outputs a comparison signal, the control module adjusts the reference voltage in a dichotomy mode to enable the reference voltage to approach the voltage amplification signal until the voltage amplification signal is equal to the reference voltage, the reference voltage with the equal reference voltage is used as a voltage measurement value of the loop to be tested, and the loop impedance of the loop to be tested is obtained based on the voltage measurement value of the loop to be tested, the current with the preset value and a preset multiple, so that automatic accurate calibration and detection of the loop impedance of the loop to be tested are achieved.
Description
Technical Field
The utility model relates to a power electronic technology field, concretely relates to return circuit impedance detection device.
Background
Each universal machine is provided with dozens of switch cards, each switch card is provided with 2048 circuits for testing, and devices such as triodes, resistors and the like used on each loop have differences in resistance characteristics after being conducted, so that the consistency of the equivalent resistance of each loop cannot be guaranteed. The universal machine is high in requirement on consistency when the circuit of the PCB is conducted, the consistency is poor, the judgment of a circuit resistance value test result is interfered, the equivalent resistance of each circuit needs to be tested, the current test mode is only simple to judge whether the tested resistance value meets the condition, and the equivalent resistance value of the circuit cannot be accurately obtained.
SUMMERY OF THE UTILITY MODEL
Therefore, the to-be-solved technical problem of the utility model lies in overcoming the defect that the equivalent resistance of return circuit can't the accurate acquisition return circuit of return circuit impedance detection method among the prior art to a return circuit impedance detection device is provided.
In order to achieve the above purpose, the utility model provides a following technical scheme:
an embodiment of the utility model provides a return circuit impedance detection device, include: the device comprises a first switch circuit, a second switch circuit, a constant current source, an amplifying circuit, a comparison circuit and a control module, wherein the first end of a loop to be tested is connected with an external power supply through the first switch circuit; the second end of the constant current source is grounded and used for outputting current with a preset value; the first end of the amplifying circuit is connected with the first end of the loop to be tested, the second end, the third end and the fourth end of the amplifying circuit are all grounded, the fifth end and the sixth end of the amplifying circuit are connected with an external power supply, and the seventh end of the amplifying circuit is connected with the first end of the comparing circuit and is used for collecting the voltage of the loop to be tested and amplifying the voltage by a preset multiple to obtain a voltage amplifying signal; the second end of the comparison circuit is connected with the control module, the sixth end and the seventh end of the comparison circuit are connected with the external power supply, and the eighth end of the comparison circuit is connected with the control module and used for comparing the voltage amplification signal with the reference voltage and outputting a comparison signal; the control module adjusts the reference voltage in a dichotomy mode to enable the reference voltage to approach a voltage amplification signal until the voltage amplification signal is equal to the reference voltage, the reference voltage with the equal voltage is used as a voltage measurement value of the loop to be tested, and the loop impedance of the loop to be tested is obtained based on the voltage measurement value of the loop to be tested, the current with a preset value and a preset multiple.
In one embodiment, the loop impedance detection apparatus further comprises: and the first end of the display circuit is connected with the external power supply, the second end of the display circuit is connected with the seventh end of the comparison circuit, and the display circuit is in an off state when the comparison signal is a high-level signal and is in an on state when the comparison signal is a low-level signal.
In one embodiment, an amplification circuit includes: the protection circuit is connected with the first end of the loop to be tested at the first end, connected with the first end of the amplification unit circuit at the second end, grounded at the third end and connected with the second end of the amplification unit circuit at the fourth end, and used for preventing the voltage overvoltage of the loop to be tested; and the third end of the amplifying unit circuit is connected with the first end of the comparison circuit, the fourth end and the fifth end of the amplifying unit circuit are connected with an external power supply, and the sixth end and the seventh end of the amplifying unit circuit are grounded and used for collecting the voltage of the loop to be tested and amplifying the voltage by a preset multiple to obtain a voltage amplifying signal.
In one embodiment, a protection circuit includes: the first end of the first diode and the first end of the second diode are connected with the first end of the loop to be tested in an anti-parallel mode through the first resistor and connected with the first end of the amplifying unit circuit, and the second end of the first diode and the second diode are connected with the second end of the amplifying unit circuit in an anti-parallel mode and grounded.
In one embodiment, an amplification unit circuit includes: the operational amplifier comprises an operational amplifier, a second resistor, a voltage stabilizing circuit, a first capacitor and a second capacitor, wherein the inverting input end of the operational amplifier is connected with the second end of the protection circuit, the non-inverting input end of the operational amplifier is connected with the third end of the protection circuit, the positive power end of the operational amplifier is connected with an external power supply and is grounded through the first capacitor, the negative power end of the operational amplifier is connected with the external power supply and is grounded through the second capacitor, and the output end of the operational amplifier is connected with the first end of the comparison circuit and is connected with the inverting input end of the comparison circuit through the voltage stabilizing circuit.
In one embodiment, a voltage regulator circuit includes: the voltage regulator comprises a first voltage regulator tube and a second voltage regulator tube, wherein the cathode of the first voltage regulator tube is connected with the inverting input end of the operational amplifier, the anode of the first voltage regulator tube is connected with the anode of the second voltage regulator tube, and the cathode of the second voltage regulator tube is connected with the output end of the comparison circuit.
In one embodiment, the comparison circuit includes: the positive phase input end of the comparator is connected with the seventh end of the amplifying circuit, the reverse phase input end of the comparator is connected with the control module, the positive power supply end of the comparator is connected with an external power supply and is grounded through the third capacitor, the negative power supply end of the comparator is connected with the external power supply and is grounded through the fourth capacitor, and the output end of the comparator is connected with the control end of the first switch tube; the first end of the first switch tube is connected with the control circuit, the second end of the first switch tube is grounded, and the first switch tube is used for being in a disconnected state when the voltage amplification signal is higher than the reference voltage and comparing the signal to be a high-level signal; when the voltage amplification signal is lower than the reference voltage, the voltage amplification signal is in a conducting state, and the comparison signal is a low-level signal.
In one embodiment, the first switching circuit includes: and the first end of the second switch tube is connected with the external power supply, the second end of the second switch tube is connected with the first end of the loop to be tested, the control end of the second switch tube is connected with the control module, and when the loop impedance of the loop to be tested is detected, the control module controls the second switch tube to be in a closed state.
In one embodiment, the second switching circuit includes: and the first end of the third switching tube is connected with the second end of the loop to be tested, the second end of the third switching tube is connected with the first end of the constant current source, the control end of the third switching tube is connected with the control module, and when the loop impedance of the loop to be tested is detected, the control module controls the third switching tube to be in a closed state.
In one embodiment, a display circuit includes: and the anode of the light-emitting diode is connected with the external power supply through the third resistor, and the cathode of the light-emitting diode is connected with the seventh end of the comparison circuit, so that the light-emitting diode is lightened when the comparison signal is a low-level signal, and the light-emitting diode is extinguished when the comparison signal is a high-level signal.
The utility model discloses technical scheme has following advantage:
the utility model provides a loop impedance detection device, the electric current of numerical value is predetermine in the constant current source output, the amplifier circuit gathers the voltage of examination return circuit of awaiting measuring, and with its enlarged preset multiple, obtain the voltage amplification signal, comparator circuit is compared voltage amplification signal and reference voltage, output comparison signal, control module adjusts reference voltage with the mode of dichotomy, make reference voltage approach voltage amplification signal, until voltage amplification signal and reference voltage equal, regard as the voltage measurement value of examination return circuit of awaiting measuring with the two equal reference voltage, and based on the voltage measurement value of examination return circuit of awaiting measuring, the electric current of numerical value is predetermine, the preset multiple, obtain the loop impedance of examination return circuit of awaiting measuring, thereby realize the automatic accurate calibration and the detection to the loop impedance of examination return circuit of awaiting measuring.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
Fig. 1 is a composition diagram of a specific example of a loop impedance detection apparatus according to an embodiment of the present invention;
fig. 2 is a composition diagram of another specific example of the loop impedance detection apparatus according to the embodiment of the present invention;
fig. 3 is a composition diagram of another specific example of the loop impedance detection apparatus according to the embodiment of the present invention;
fig. 4 is a specific circuit structure diagram of the loop impedance detection apparatus according to an embodiment of the present invention;
fig. 5 is a composition diagram of another specific example of the loop impedance detection apparatus according to the embodiment of the present invention.
Detailed Description
The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and obviously, the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; the two elements may be directly connected or indirectly connected through an intermediate medium, or may be communicated with each other inside the two elements, or may be wirelessly connected or wired connected. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Furthermore, the technical features mentioned in the different embodiments of the invention described below can be combined with each other as long as they do not conflict with each other.
Examples
An embodiment of the utility model provides a loop impedance detection device is applied to, as shown in fig. 1, include: the circuit comprises a first switch circuit 1, a second switch circuit 2, a constant current source 3, an amplifying circuit 4, a comparison circuit 5 and a control module 6.
As shown in fig. 1, the utility model discloses the first end in the return circuit that awaits measuring is connected with external power supply through first switch circuit 1, and its second end is connected with the first end of constant current source 3 through second switch circuit 2, when carrying out the loop impedance to the return circuit that awaits measuring and detecting, first switch circuit 1 of control module 6 control and second switch circuit 2 are in the closed state.
As shown in fig. 2, the utility model discloses loop impedance detection device of embodiment can also include a plurality of first switch circuit 1 and second switch circuit 2, thereby realize testing many examination return circuits that await measuring automatically, specifically, control module 6 controls first switch circuit # A, second switch circuit # A is closed, test examination return circuit # A that awaits measuring, after the test is accomplished, control module 6 controls first switch circuit # B, second switch circuit # B is closed, test examination return circuit # B that awaits measuring, after the test is accomplished, control module 6 controls first switch circuit # C, second switch circuit # C is closed, test examination return circuit # C that awaits measuring.
As shown in fig. 1, the second terminal of the constant current source 3 according to the embodiment of the present invention is grounded, and is used for outputting a current of a preset value.
As shown in fig. 1, the utility model discloses amplifier circuit 4's first end is connected with the first end of the return circuit that awaits measuring, and its second end, third end, fourth end are all earthed, and its fifth end, sixth end are connected with external power supply, and its seventh end is connected with comparator circuit 5's first end for gather the voltage of the return circuit that awaits measuring, and with its amplification preset multiple, obtain the voltage amplification signal.
As shown in fig. 1, the second end of the comparison circuit 5 of the embodiment of the present invention is connected to the control module 6, the third end, the fourth end and the fifth end are grounded, the sixth end and the seventh end are connected to the external power source, and the eighth end is connected to the control module 6, so as to compare the voltage amplification signal with the reference voltage and output the comparison signal.
The utility model discloses reference voltage is adjusted with dichotomy mode to control module 6, makes reference voltage approach voltage amplification signal, until voltage amplification signal with reference voltage equals, regards as the voltage measurement value of the return circuit that awaits measuring with the two equal reference voltage to based on the voltage measurement value of the return circuit that awaits measuring, the electric current of presetting numerical value, the multiple of presetting, obtain the return circuit impedance of the return circuit that awaits measuring.
The utility model discloses after control module 6 obtained the voltage measurement value of the return circuit that awaits measuring, can calculate the return circuit impedance (equivalent resistance) that obtains the return circuit that awaits measuring based on formula (1).
Wherein R is the loop impedance of the loop to be tested, V1-2For the voltage measurement value of the loop to be tested, I is the current with a preset value, and rmp is a preset multiple.
It should be noted that the utility model provides a loop impedance detection device can realize the automatic accuracy calibration and the loop detection to the return circuit that awaits measuring, wherein, after the return circuit impedance (equivalent resistance) of return circuit that awaits measuring is surveyed through above-mentioned method and formula (1) to the automatic accuracy detection, replace the return circuit impedance of the return circuit that awaits measuring before with the calculated result to realize the accuracy calibration; the loop detection is directed at a device similar to a switch card, the device comprises a plurality of loops to be tested, part of the loops to be tested are used as sample loops, loop impedance of each sample loop is obtained through the method and the formula (1), an average impedance value of the sample loops is obtained, then the loop impedance of each loop to be tested is measured through the method and the formula (1), the loop impedance of each loop to be tested is compared with the average impedance value, a deviation value of each loop to be tested is obtained, and the loops to be tested with the deviation value exceeding a preset deviation threshold value are regarded as unqualified loops.
In an embodiment, as shown in fig. 3, the loop impedance detecting apparatus further includes: and the first end of the display circuit 7 is connected with the external power supply, the second end of the display circuit is connected with the seventh end of the comparison circuit 5, and the display circuit is used for being in a turn-off state when the comparison signal is a high-level signal and being in a turn-on state when the comparison signal is a low-level signal.
Specifically, as shown in fig. 4, the display circuit 7 includes: and the third resistor R3 and the light emitting diode D5, wherein the anode of the light emitting diode is connected to the external power supply through the third resistor, and the cathode of the light emitting diode is connected to the seventh end of the comparison circuit 5, so that the light emitting diode is turned on when the comparison signal is a low level signal, and the light emitting diode is turned off when the comparison signal is a high level signal.
In a specific embodiment, as shown in fig. 4, the first switch circuit 1 includes: the first end of the second switch tube S1 is connected to the external power supply, the second end of the second switch tube S1 is connected to the first end of the loop to be tested, the control end of the second switch tube S1 is connected to the control module 6, and when the loop impedance of the loop to be tested is detected, the control module 6 controls the second switch tube S1 to be in a closed state.
As shown in fig. 4, the second switch circuit 2 includes: and a first end of the third switch tube S2 is connected to the second end of the to-be-tested loop, a second end of the third switch tube S2 is connected to the first end of the constant current source 3, and a control end of the third switch tube S2 is connected to the control module 6, and when loop impedance detection is performed on the to-be-tested loop, the control module 6 controls the third switch tube S2 to be in a closed state.
The first switch circuit 1 and the second switch circuit 2 of the embodiment of the present invention are not limited to the circuit structure shown in fig. 4, but can be other circuits with the same function, and are not repeated herein.
In one embodiment, as shown in fig. 5, the amplifying circuit 4 includes: a protection circuit 41 and an amplification unit circuit 42.
As shown in fig. 5, the first end of the protection circuit 41 of the embodiment of the present invention is connected to the first end of the loop to be tested, the second end thereof is connected to the first end of the amplifying unit circuit 42, the third end thereof is grounded, and the fourth end thereof is connected to the second end of the amplifying unit circuit 42, so as to prevent the voltage overvoltage of the loop to be tested.
As shown in fig. 4, the protection circuit 41 according to the embodiment of the present invention includes: a first resistor R1, a first diode D1 and a second diode D2, wherein a first end of the first diode D1 connected in anti-parallel with the second diode D2 is connected to a first end of the loop to be tested through the first resistor R1 and to a first end of the amplifying unit circuit 42, and a second end of the first diode D1 connected in anti-parallel with the second diode D2 is connected to a second end of the amplifying unit circuit 42 and to ground.
As shown in fig. 5, the third end of the amplifying unit circuit 42 of the embodiment of the present invention is connected to the first end of the comparison circuit 5, the fourth end and the fifth end thereof are connected to the external power source, and the sixth end and the seventh end thereof are grounded, so as to amplify the voltage of the loop to be tested by a predetermined multiple, thereby obtaining the voltage amplification signal.
As shown in fig. 4, the amplification unit circuit 42 according to the embodiment of the present invention includes: the operational amplifier U1, the second resistor R2, the voltage stabilizing circuit 421, the first capacitor C1 and the second capacitor C2, wherein the inverting input terminal of the operational amplifier U1 is connected to the second terminal of the protection circuit 41, the non-inverting input terminal thereof is connected to the third terminal of the protection circuit 41, the positive power terminal thereof is connected to the external power source and grounded through the first capacitor C1, the negative power terminal thereof is connected to the external power source and grounded through the second capacitor C2, and the output terminal thereof is connected to the first terminal of the comparison circuit 5 and connected to the inverting input terminal thereof through the voltage stabilizing circuit 421.
As shown in fig. 4, the voltage stabilizing circuit 421 includes: a first voltage regulator tube D3 and a second voltage regulator tube D4, wherein the cathode of the first voltage regulator tube D3 is connected with the inverting input terminal of the operational amplifier U1, the anode thereof is connected with the anode of the second voltage regulator tube D4, and the cathode of the second voltage regulator tube D4 is connected with the output terminal of the comparison circuit 5.
In one embodiment, as shown in fig. 4, the comparison circuit 5 includes: the circuit comprises a comparator U2, a third capacitor C3, a fourth capacitor C4 and a first switch tube S3, wherein the positive phase input end of the comparator U2 is connected with the seventh end of the amplifying circuit 4, the negative phase input end of the comparator U2 is connected with the control module 6, the positive power end of the comparator U2 is connected with an external power supply and is grounded through the third capacitor C3, the negative power end of the comparator U3838 is connected with the external power supply and is grounded through the fourth capacitor C4, and the output end of the comparator U2 is connected with the control end of the first switch tube S3; the first end of the first switch tube S3 is connected to the control circuit, and the second end is grounded, so that when the voltage amplification signal is higher than the reference voltage Vref, the first switch tube is in an off state, and the comparison signal is a high level signal; when the voltage amplification signal is lower than the reference voltage Vref, the voltage amplification signal is in a conducting state, and the comparison signal is a low level signal.
Specifically, when the loop to be tested is tested, the control module 6 may first assign a reference voltage Vref, when the voltage amplification signal is higher than the reference voltage Vref, the first switching tube S3 is turned off, and the comparison signal is a high level signal, the control module 6 adjusts the reference voltage in a dichotomy manner until the voltage amplification signal is equal to the reference voltage; after the control module 6 may further assign a value to the reference voltage, when the voltage of the loop to be tested is lower than the reference voltage Vref, the first switch tube S3 is turned on, and the comparison signal is a low level signal, then the control module 6 adjusts the reference voltage in a dichotomy manner until the voltage amplification signal is equal to the reference voltage, and the reference voltage when the voltage amplification signal is equal to the reference voltage is used as the voltage measurement value of the loop to be tested.
The utility model provides a loop impedance detection device, the electric current of numerical value is predetermine in the constant current source output, the amplifier circuit gathers the voltage of examination return circuit of awaiting measuring, and with its enlarged preset multiple, obtain the voltage amplification signal, comparator circuit is compared voltage amplification signal and reference voltage, output comparison signal, control module adjusts reference voltage with the mode of dichotomy, make reference voltage approach voltage amplification signal, until voltage amplification signal and reference voltage equal, regard as the voltage measurement value of examination return circuit of awaiting measuring with the two equal reference voltage, and based on the voltage measurement value of examination return circuit of awaiting measuring, the electric current of numerical value of predetermineeing, the preset multiple, obtain the loop impedance of examination return circuit of awaiting measuring, thereby realize the accurate calibration and the detection to the loop impedance of examination return circuit of awaiting measuring.
It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious changes and modifications can be made without departing from the scope of the invention.
Claims (10)
1. A loop impedance detection device, comprising: a first switch circuit, a second switch circuit, a constant current source, an amplifying circuit, a comparison circuit and a control module, wherein,
the first end of the loop to be tested is connected with an external power supply through a first switch circuit, the second end of the loop to be tested is connected with the first end of the constant current source through a second switch circuit, and when loop impedance detection is carried out on the loop to be tested, the control module controls the first switch circuit and the second switch circuit to be in a closed state;
the second end of the constant current source is grounded and used for outputting a current with a preset value;
the first end of the amplifying circuit is connected with the first end of the loop to be tested, the second end, the third end and the fourth end of the amplifying circuit are all grounded, the fifth end and the sixth end of the amplifying circuit are connected with an external power supply, and the seventh end of the amplifying circuit is connected with the first end of the comparing circuit and is used for collecting the voltage of the loop to be tested and amplifying the voltage by a preset multiple to obtain a voltage amplifying signal;
the second end of the comparison circuit is connected with the control module, the third end, the fourth end and the fifth end of the comparison circuit are grounded, the sixth end and the seventh end of the comparison circuit are connected with an external power supply, and the eighth end of the comparison circuit is connected with the control module and used for comparing the voltage amplification signal with a reference voltage and outputting a comparison signal;
the control module adjusts the reference voltage in a dichotomy mode to enable the reference voltage to approach the voltage amplification signal until the voltage amplification signal is equal to the reference voltage, the reference voltage with the equal voltage is used as a voltage measurement value of the loop to be tested, and loop impedance of the loop to be tested is obtained based on the voltage measurement value of the loop to be tested, current with a preset value and a preset multiple.
2. The loop impedance detecting apparatus according to claim 1, further comprising:
and the first end of the display circuit is connected with an external power supply, the second end of the display circuit is connected with the seventh end of the comparison circuit, and the display circuit is in a turn-off state when the comparison signal is a high-level signal and is in a turn-on state when the comparison signal is a low-level signal.
3. The loop impedance detection device of claim 1, wherein the amplification circuit comprises: a protection circuit and an amplification unit circuit, wherein,
the first end of the protection circuit is connected with the first end of the loop to be tested, the second end of the protection circuit is connected with the first end of the amplifying unit circuit, the third end of the protection circuit is grounded, and the fourth end of the protection circuit is connected with the second end of the amplifying unit circuit and is used for preventing the voltage overvoltage of the loop to be tested;
and the third end of the amplifying unit circuit is connected with the first end of the comparison circuit, the fourth end and the fifth end of the amplifying unit circuit are connected with an external power supply, and the sixth end and the seventh end of the amplifying unit circuit are grounded and used for collecting the voltage of the loop to be tested and amplifying the voltage by a preset multiple to obtain a voltage amplifying signal.
4. The loop impedance detection device according to claim 3, wherein the protection circuit comprises: a first resistor, a first diode and a second diode, wherein,
the first end of the first diode and the first end of the second diode after being connected in anti-parallel are connected with the first end of the loop to be tested through the first resistor and connected with the first end of the amplifying unit circuit, and the second end of the first diode and the second diode after being connected in anti-parallel is connected with the second end of the amplifying unit circuit and grounded.
5. The loop impedance detection device according to claim 3, wherein the amplification unit circuit includes: an operational amplifier, a second resistor, a voltage regulator circuit, a first capacitor, a second capacitor,
the inverting input end of the operational amplifier is connected with the second end of the protection circuit, the non-inverting input end of the operational amplifier is connected with the third end of the protection circuit, the positive power end of the operational amplifier is connected with an external power supply and is grounded through a first capacitor, the negative power end of the operational amplifier is connected with the external power supply and is grounded through a second capacitor, and the output end of the operational amplifier is connected with the first end of the comparison circuit and is connected with the inverting input end of the comparison circuit through a voltage stabilizing circuit.
6. The loop impedance detection device of claim 5, wherein the voltage regulator circuit comprises: a first voltage regulator tube and a second voltage regulator tube, wherein,
the cathode of the first voltage-stabilizing tube is connected with the inverting input end of the operational amplifier, the anode of the first voltage-stabilizing tube is connected with the anode of the second voltage-stabilizing tube, and the cathode of the second voltage-stabilizing tube is connected with the output end of the comparison circuit.
7. The loop impedance detection device of claim 1, wherein the comparison circuit comprises: a comparator, a third capacitor, a fourth capacitor, and a first switch tube, wherein,
the positive phase input end of the comparator is connected with the seventh end of the amplifying circuit, the reverse phase input end of the comparator is connected with the control module, the positive pole power supply end of the comparator is connected with an external power supply and is grounded through a third capacitor, the negative pole power supply end of the comparator is connected with the external power supply and is grounded through a fourth capacitor, and the output end of the comparator is connected with the control end of the first switch tube;
the first end of the first switch tube is connected with the control circuit, the second end of the first switch tube is grounded, the first switch tube is in a disconnected state when the voltage amplification signal is higher than the reference voltage, and the comparison signal is a high-level signal; when the voltage amplification signal is lower than the reference voltage, the voltage amplification signal is in a conducting state, and the comparison signal is a low-level signal.
8. The loop impedance detection device of claim 1, wherein the first switch circuit comprises:
and the first end of the second switch tube is connected with an external power supply, the second end of the second switch tube is connected with the first end of the loop to be tested, the control end of the second switch tube is connected with the control module, and when loop impedance detection is carried out on the loop to be tested, the control module controls the second switch tube to be in a closed state.
9. The loop impedance detection device of claim 1, wherein the second switching circuit comprises:
and the first end of the third switching tube is connected with the second end of the loop to be tested, the second end of the third switching tube is connected with the first end of the constant current source, the control end of the third switching tube is connected with the control module, and when loop impedance detection is carried out on the loop to be tested, the control module controls the third switching tube to be in a closed state.
10. The loop impedance detection device according to claim 2, wherein the display circuit comprises: a third resistor and a light emitting diode, wherein,
the anode of the light emitting diode is connected with an external power supply through a third resistor, the cathode of the light emitting diode is connected with the seventh end of the comparison circuit, and the light emitting diode is used for being lightened when the comparison signal is a low level signal and being extinguished when the comparison signal is a high level signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120816414.7U CN214750559U (en) | 2021-04-20 | 2021-04-20 | Loop impedance detection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120816414.7U CN214750559U (en) | 2021-04-20 | 2021-04-20 | Loop impedance detection device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN214750559U true CN214750559U (en) | 2021-11-16 |
Family
ID=78611608
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202120816414.7U Active CN214750559U (en) | 2021-04-20 | 2021-04-20 | Loop impedance detection device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN214750559U (en) |
-
2021
- 2021-04-20 CN CN202120816414.7U patent/CN214750559U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101981459B (en) | Programmable gain trans-impedance amplifier overload recovery circuit | |
| WO2016179964A1 (en) | Detection circuit and detection method for high-side current | |
| US20130038343A1 (en) | Test circuit for testing short-circuit | |
| CN207319096U (en) | Electronic circuit | |
| CN213600773U (en) | Current measuring circuit and measuring instrument capable of automatically switching measuring range | |
| CN109633404B (en) | PXI-based avalanche photodetector electrical characteristic test system | |
| US11555849B2 (en) | Detection device for detecting line quality of electric circuit | |
| CN214750559U (en) | Loop impedance detection device | |
| CN111308274A (en) | Circuit short circuit and short circuit position detection device | |
| US10944259B2 (en) | System and method for over voltage protection in both positive and negative polarities | |
| CN219016553U (en) | Three-phase misconnection prevention detection circuit and air conditioner | |
| CN216927045U (en) | Detection circuit and polarity discrimination device | |
| CN110673072A (en) | Partial discharge signal simulation device with temperature measurement and overvoltage protection | |
| CN210803660U (en) | Weak current measuring device of ATE system | |
| CN2304130Y (en) | D. C. resistance detecting instrument | |
| CN209310835U (en) | A kind of detection device of optical sensor | |
| CN212111649U (en) | Short circuit and short circuit distance detection device | |
| CN213364866U (en) | Current detection circuit | |
| CN220626544U (en) | Detection circuit and device for constant current input port | |
| CN215678544U (en) | Test equipment | |
| TWI822524B (en) | Voltage detection device with protective function | |
| CN113219257B (en) | Parameter measuring circuit of capacitor and ESR capacity measuring instrument of capacitor | |
| CN221105824U (en) | Human body comprehensive resistance test system | |
| CN109061524A (en) | Power supply test circuit and method | |
| CN216387276U (en) | Device and circuit for testing performance of tube core |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |