CN214150864U - Transformer direct resistance rapid tester with short measuring time - Google Patents
Transformer direct resistance rapid tester with short measuring time Download PDFInfo
- Publication number
- CN214150864U CN214150864U CN202023032133.7U CN202023032133U CN214150864U CN 214150864 U CN214150864 U CN 214150864U CN 202023032133 U CN202023032133 U CN 202023032133U CN 214150864 U CN214150864 U CN 214150864U
- Authority
- CN
- China
- Prior art keywords
- resistor
- voltage
- diode
- transformer
- winding
- 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
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
Abstract
The utility model provides a short transformer of measuring time directly hinders quick tester, including the constant current source, the constant current source includes voltage-controlled switching power supply, triode Q1 ~ Q2, comparator IC1, resistance R0 ~ R5. The utility model discloses a constant current source constant current forms is the influence of establishing at reference voltage not receiving the winding L1 that awaits measuring, and the stability and the accuracy of constant current when having strengthened the steady state have guaranteed high-pressure quick charge again at transient process simultaneously, have shortened the time that the constant current was established, and direct current resistance's measuring time is short.
Description
Technical Field
The utility model relates to a transformer direct current resistance test technical field especially relates to a short transformer of measuring time directly hinders quick tester.
Background
The measurement of the direct current resistance of the transformer winding has very important significance for inspecting the process quality of a transformer product in the production process, finding the defects of the transformer and inspecting, analyzing and judging the transformer after the fault. The purpose of measuring the direct-current resistance of the transformer winding is to check the welding quality of the transformer winding, whether the winding has a turn-to-turn short circuit, whether the contact of a tap switch is good, whether the winding and an outgoing line are broken, whether the connection of parallel branches is correct, whether a layer turn-to-turn short circuit exists and the like. The measurement of the direct current resistance of the transformer winding is usually injected through a constant current source, the voltage at two ends of the winding to be measured and the current flowing through the winding to be measured are respectively detected, and the direct current resistance is calculated according to ohm's law. In a traditional transformer direct resistance tester, the constant current of a constant current source is established for a long time, so that the measurement time of a direct current resistor is long.
SUMMERY OF THE UTILITY MODEL
In view of this, the utility model provides a short transformer of measuring time directly hinders quick tester to solve the problem that constant current source constant current set-up time is long among the traditional transformer directly hinders the tester.
The technical scheme of the utility model is realized like this: a rapid tester for direct resistance of a transformer with short measurement time comprises a constant current source, wherein the constant current source comprises a voltage-controlled switching power supply, triodes Q1-Q2, a comparator IC1 and resistors R0-R5;
the positive electrode of the output end of the voltage-controlled switching power supply is grounded through a triode Q1 and a resistor R0 in sequence, the negative electrode of the output end of the voltage-controlled switching power supply is grounded through a transformer winding L1 to be tested, the base electrode of a triode Q1 is connected with the collector electrode of a triode Q2, and the emitter electrode of a triode Q2 is connected with the emitter electrode of a triode Q1;
the +12V power supply is connected with the base electrode of the triode Q2 through a resistor R2 and a resistor R4 in sequence, the in-phase end of the comparator IC1 is connected with reference voltage through a resistor R5, and the emitter of the triode Q1 and the common end of the resistor R0 are connected with the inverting end of the comparator IC1 through a resistor R3.
Optionally, the constant current source further includes a resistor R1 and a zener diode D1, the +12V power supply is further grounded through a resistor R1 and a zener diode D1 in sequence, and the reference voltage is output from a common end of the resistor R1 and the zener diode D1.
Optionally, the transformer direct resistance rapid tester with short measurement time further comprises a discharge circuit, wherein the discharge circuit comprises a diode D2, a resistor R6 and a capacitor C1;
one end of the winding L1 to be tested, which is connected with the negative electrode of the output end of the voltage-controlled switch power supply, sequentially passes through the positive electrode of the diode D2, the negative electrode of the diode D2 and the resistor R6 to be connected with the other end of the winding L1 to be tested, and the capacitor C1 is connected with the resistor R6 in parallel.
Optionally, the discharge circuit further includes a bidirectional transient suppression diode D3, and one end of the winding L1 to be tested is connected to the other end of the winding L1 to be tested through the bidirectional transient suppression diode D3.
Optionally, the discharge circuit further includes an optocoupler U1, a light emitting diode D4, and resistors R7 to R9;
the negative electrode of the diode D2 and the common end of the resistor R6 are sequentially connected with one end, close to the positive electrode of the output end of the voltage-controlled switching power supply, of the winding L1 to be tested through the resistor R7, the resistor R8 and the light-emitting diode of the optocoupler U1, and the +5V power supply is sequentially grounded through the resistor R9, the light-emitting diode D4 and the phototriode of the optocoupler U1.
Optionally, the discharge circuit further includes a zener diode D5, and a common end of the resistor R7 and the resistor R8 is connected to a cathode of the light emitting diode of the optocoupler U1 through a cathode of the zener diode D5 and an anode of the zener diode D5 in sequence.
Optionally, the transformer direct resistance rapid tester with short measurement time further comprises a resistance voltage dividing circuit, a voltage follower, an RC filter circuit, an in-phase amplifier, an AD conversion module and a single chip microcomputer, and the voltage at the two ends of the winding to be tested L1 is divided by the resistance voltage dividing circuit and then sequentially input to the single chip microcomputer through the voltage follower, the RC filter circuit, the in-phase amplifier and the AD conversion module.
The utility model discloses a transformer directly hinders quick tester has following beneficial effect for prior art:
(1) the constant current of the constant current source is formed by establishing that the reference voltage is not influenced by the winding L1 to be measured, the stability and the accuracy of the constant current in a steady state are enhanced, meanwhile, the high-voltage quick charging is ensured in a transient process, the time for establishing the constant current is shortened, and the measuring time of the direct current resistor is short;
(2) when the constant current source is disconnected, the back electromotive force generated at the two ends of the winding L1 to be tested forms a discharge loop through the diode D2, the parallel resistor R6 and the capacitor C1, so that the back electromotive force can be eliminated, and the protection effect is achieved;
(3) the voltage follower and the RC filter circuit jointly improve the reliability of detecting the voltage at two ends of the winding L1 to be tested, so that the test precision of the direct-current resistance is improved.
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 description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only 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 circuit diagram of a constant current source of the present invention;
fig. 2 is a circuit diagram of a discharge circuit of the present invention;
fig. 3 is the structural block diagram of the transformer direct resistance rapid tester of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work all belong to the protection scope of the present invention.
As shown in fig. 3, the fast tester for direct resistance of a transformer with short measurement time in the present embodiment includes a constant current source, as shown in fig. 1, the constant current source includes a voltage-controlled switching power supply, transistors Q1-Q2, a comparator IC1, and resistors R0-R5. The positive electrode of the output end of the voltage-controlled switching power supply is grounded through a triode Q1 and a resistor R0 in sequence, the negative electrode of the output end of the voltage-controlled switching power supply is grounded through a transformer winding L1 to be tested, the base electrode of the triode Q1 is connected with the collector electrode of the triode Q2, and the emitter electrode of the triode Q2 is connected with the emitter electrode of the triode Q1. The +12V power supply is connected with the base electrode of the triode Q2 through a resistor R2 and a resistor R4 in sequence, the in-phase end of the comparator IC1 is connected with reference voltage through a resistor R5, and the emitter of the triode Q1 and the common end of the resistor R0 are connected with the inverting end of the comparator IC1 through a resistor R3.
In this embodiment, the input terminal of the voltage-controlled switching power supply is connected to the 220V ac power supply, and the output terminal of the voltage-controlled switching power supply outputs the low-voltage dc power, such as 24V. When the voltage-controlled switching power supply is switched on, because the current of the winding L1 to be tested cannot change suddenly, the voltage of the same-phase end of the comparator IC1 is higher than that of the opposite-phase end, the comparator IC1 outputs high level, the triode Q1 is in a saturated state, the winding L1 to be tested is charged in a high-voltage forced mode, the feedback voltage input to the opposite-phase end of the comparator IC1 is increased along with the increase of the current, and when the reference voltage is increased, the comparator IC1 enters an amplification state from a comparison state and finally tends to be stable. The comparator IC1 compares the sampling voltage of the sampling resistor R0 with the reference voltage, amplifies the compared error result through the triode Q2 to be used as a control signal of the triode Q1, amplifies the error amplification signal through the triode Q1, and changes the output voltage of the triode Q1, so that the constant current is achieved. Because the constant current is formed when the reference voltage is not influenced by the winding L1 to be measured, the stability and the accuracy of the constant current in a steady state are enhanced, meanwhile, the high-voltage quick charging is ensured in a transient process, the time for establishing the constant current is shortened, and the measuring time of the direct current resistance is short. In fig. 1, after the constant current is established, Vo is equal to the reference voltage Vref, and thus the current is equal to Vref/R0.
Further, as shown in fig. 1, the constant current source of this embodiment further includes a resistor R1 and a zener diode D1, the +12V power supply is further grounded via a resistor R1 and a zener diode D1 in sequence, and a common terminal of the resistor R1 and the zener diode D1 outputs the reference voltage. The +12V voltage is divided by the resistor R1 and the zener diode D1, and the zener diode D1 outputs the reference voltage.
The constant current source needs to be disconnected when the measurement is completed, and the transformer is inductive equipment and has a self-induced electromotive force effect, so that when the connecting line of the measurement loop is cut off suddenly, the generated counter electromotive force is extremely high, and great harm is caused to measurement personnel and equipment, and the selection is realized. Therefore, as shown in fig. 3, the fast tester for direct resistance of transformer of this embodiment further includes a discharge circuit, as shown in fig. 2, the discharge circuit includes a diode D2, a resistor R6, and a capacitor C1. One end of the winding L1 to be tested, which is connected with the negative electrode of the output end of the voltage-controlled switch power supply, sequentially passes through the positive electrode of the diode D2, the negative electrode of the diode D2 and the resistor R6 to be connected with the other end of the winding L1 to be tested, and the capacitor C1 is connected with the resistor R6 in parallel. When the constant current source is disconnected, the back electromotive force generated at the two ends of the winding L1 to be tested forms a discharge loop through the diode D2, the parallel resistor R6 and the capacitor C1, so that the back electromotive force can be eliminated, and the protection effect is achieved. The diode D2 is used to avoid current flow through the discharge loop during normal measurement.
Further, as shown in fig. 2, the discharge circuit of this embodiment further includes a bidirectional transient suppression diode D3, and one end of the winding L1 to be tested is connected to the other end of the winding L1 to be tested through the bidirectional transient suppression diode D3. The bi-directional transient suppression diode D3 is used for overvoltage protection during normal measurement and when the constant current source is disconnected, as well as for back emf suppression.
As shown in fig. 2, the discharge circuit of the present embodiment further includes an optocoupler U1, a light emitting diode D4, and resistors R7 to R9. The negative electrode of the diode D2 and the common end of the resistor R6 are sequentially connected with one end, close to the positive electrode of the output end of the voltage-controlled switching power supply, of the winding L1 to be tested through the resistor R7, the resistor R8 and the light-emitting diode of the optocoupler U1, and the +5V power supply is sequentially grounded through the resistor R9, the light-emitting diode D4 and the phototriode of the optocoupler U1. When the constant current source is disconnected, the counter electromotive force also sequentially flows through a light emitting diode of the optocoupler U1 through the diode D2, the resistor R7 and the resistor R8, a phototriode of the optocoupler U1 is conducted, and the light emitting diode D4 emits light to indicate the discharging state; after the discharge is finished, no current flows through the light emitting diode of the optocoupler U1, and the light emitting diode D4 is extinguished to indicate the state of the discharge completion. The resistor R7 and the resistor R8 are used for voltage division, and the resistor R9 is used for current limiting. Further, the discharge circuit further comprises a voltage stabilizing diode D5, and the common end of the resistor R7 and the resistor R8 is connected with the cathode of the light emitting diode of the optocoupler U1 through the cathode of the voltage stabilizing diode D5 and the anode of the voltage stabilizing diode D5 in sequence. The voltage stabilizing diode D5 is used for stabilizing the voltage at the two ends of the light emitting diode of the optocoupler U1, and the optocoupler U1 is prevented from being burnt by overvoltage.
As can be seen from the above, in this embodiment, the current flowing through the winding L1 to be tested can be calculated by the reference voltage and the resistor R0, and the dc resistance of the winding L1 to be tested can be calculated by the ohmic current only after the voltages at the two ends of the winding L1 to be tested are collected. As shown in fig. 3, the fast tester for direct resistance of a transformer with short measurement time in this embodiment further includes a resistor voltage-dividing circuit, a voltage follower, an RC filter circuit, an in-phase amplifier, an AD conversion module, and a single chip, wherein the voltage at two ends of the winding L1 to be measured is divided by the resistor voltage-dividing circuit and then sequentially input to the single chip through the voltage follower, the RC filter circuit, the in-phase amplifier, and the AD conversion module. The resistance voltage division circuit is used for dividing the voltage at two ends of the winding L1 to be measured during measurement; the voltage follower is in a high-resistance state to the resistance voltage division circuit and in a low-resistance state to the post-stage circuit, so that the resistance voltage division circuit and the post-stage circuit are isolated, and the influence of the post-stage circuit on the output of the resistance voltage division circuit is avoided; the RC filter circuit can filter interference signals in the circuit, and the interference signals are prevented from influencing the output of the resistance voltage division circuit; the voltage follower and the RC filter circuit jointly improve the reliability of the detected voltage signal, so that the testing precision of the direct-current resistor is improved.
The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (7)
1. A short-time measurement transformer direct resistance rapid tester comprises a constant current source, and is characterized in that the constant current source comprises a voltage-controlled switching power supply, a triode Q1-Q2, a comparator IC1 and a resistor R0-R5;
the positive electrode of the output end of the voltage-controlled switching power supply is grounded through a triode Q1 and a resistor R0 in sequence, the negative electrode of the output end of the voltage-controlled switching power supply is grounded through a transformer winding L1 to be tested, the base electrode of a triode Q1 is connected with the collector electrode of a triode Q2, and the emitter electrode of a triode Q2 is connected with the emitter electrode of a triode Q1;
the +12V power supply is connected with the base electrode of a triode Q2 through a resistor R2 and a resistor R4 in sequence, the in-phase end of a comparator IC1 is connected with reference voltage through a resistor R5, and the emitter of the triode Q1 and the common end of a resistor R0 are connected with the inverting end of the comparator IC1 through a resistor R3.
2. The fast tester for direct resistance of transformer with short measurement time as claimed in claim 1, wherein the constant current source further comprises a resistor R1 and a zener diode D1, the +12V power source further passes through the resistor R1 and the zener diode D1 in sequence and is grounded, and the common terminal of the resistor R1 and the zener diode D1 outputs the reference voltage.
3. The fast tester for direct resistance of transformer with short measuring time as claimed in claim 1, further comprising a discharging circuit, wherein the discharging circuit comprises a diode D2, a resistor R6 and a capacitor C1;
one end of the winding L1 to be tested, which is connected with the negative electrode of the output end of the voltage-controlled switch power supply, sequentially passes through the positive electrode of the diode D2, the negative electrode of the diode D2 and the resistor R6 to be connected with the other end of the winding L1 to be tested, and the capacitor C1 is connected with the resistor R6 in parallel.
4. The fast tester for direct resistance of transformer with short measurement time as claimed in claim 3, wherein the discharge circuit further comprises a bi-directional transient suppression diode D3, one end of the winding L1 to be tested is connected to the other end of the winding L1 to be tested via the bi-directional transient suppression diode D3.
5. The rapid tester for direct resistance of transformer with short measurement time as claimed in claim 3, wherein the discharge circuit further comprises an optocoupler U1, a light emitting diode D4, and resistors R7-R9;
the negative electrode of the diode D2 and the common end of the resistor R6 are sequentially connected with one end, close to the positive electrode of the output end of the voltage-controlled switching power supply, of the winding L1 to be tested through the resistor R7, the resistor R8 and the light-emitting diode of the optocoupler U1, and the +5V power supply is sequentially grounded through the resistor R9, the light-emitting diode D4 and the phototriode of the optocoupler U1.
6. The fast tester for direct resistance of transformer with short measurement time as claimed in claim 5, wherein the discharge circuit further comprises a zener diode D5, and the common terminal of the resistor R7 and the resistor R8 is connected to the cathode of the light emitting diode of the optocoupler U1 through the cathode of the zener diode D5 and the anode of the zener diode D5 in sequence.
7. The transformer direct resistance rapid tester with short measurement time as claimed in claim 1, further comprising a resistance voltage dividing circuit, a voltage follower, an RC filter circuit, a non-inverting amplifier, an AD conversion module and a single chip microcomputer, wherein the voltage at two ends of the winding L1 to be tested is divided by the resistance voltage dividing circuit and then is sequentially input to the single chip microcomputer through the voltage follower, the RC filter circuit, the non-inverting amplifier and the AD conversion module.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202023032133.7U CN214150864U (en) | 2020-12-16 | 2020-12-16 | Transformer direct resistance rapid tester with short measuring time |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202023032133.7U CN214150864U (en) | 2020-12-16 | 2020-12-16 | Transformer direct resistance rapid tester with short measuring time |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN214150864U true CN214150864U (en) | 2021-09-07 |
Family
ID=77588494
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202023032133.7U Active CN214150864U (en) | 2020-12-16 | 2020-12-16 | Transformer direct resistance rapid tester with short measuring time |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN214150864U (en) |
-
2020
- 2020-12-16 CN CN202023032133.7U patent/CN214150864U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN216434343U (en) | Novel residual current device calibration device | |
| CN214150864U (en) | Transformer direct resistance rapid tester with short measuring time | |
| CN204945296U (en) | A kind of cellular phone data line tester | |
| CN204903740U (en) | Power detecting circuit | |
| US8513971B2 (en) | Zener diode detecting circuit | |
| CN203232106U (en) | Multiple failure diagnostic device for high-voltage switch cabinet | |
| CN111077356B (en) | Current detection circuit, method, apparatus and storage medium | |
| CN219016553U (en) | Three-phase misconnection prevention detection circuit and air conditioner | |
| CN105467218A (en) | Contact resistance testing method of circuit breaker used for short-circuit protection | |
| CN111308274A (en) | Circuit short circuit and short circuit position detection device | |
| CN113960341B (en) | Ammeter and zero line-falling detection circuit thereof | |
| CN115951207A (en) | Test circuit and system of solid relay | |
| CN204964673U (en) | Coil turn -to -turn short circuit tester | |
| CN104181370A (en) | Load current detection circuit and detection device | |
| CN204166076U (en) | A kind of Multifunction silicon controlled tester being applied to big current rectifying installation | |
| CN210514584U (en) | Zinc oxide arrester live-line tester | |
| CN204154856U (en) | Triode amplifies test circuit | |
| CN104165867A (en) | Solution concentration detection device and method | |
| CN110346731B (en) | Battery current detection circuit for communication | |
| CN105203906A (en) | Coil interturn short-circuit tester | |
| CN105675996A (en) | Power cell internal resistance on-line monitoring system and method | |
| CN201974504U (en) | Nondestructive withstand voltage tester | |
| CN203490311U (en) | Two-stage filter detection circuit | |
| CN106918738B (en) | Metering control system of shunt in electric energy meter | |
| CN219417598U (en) | High-precision loop resistance tester |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |