CN215641512U - Hand-held transformer direct-current resistance tester - Google Patents
Hand-held transformer direct-current resistance tester Download PDFInfo
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- CN215641512U CN215641512U CN202122108857.3U CN202122108857U CN215641512U CN 215641512 U CN215641512 U CN 215641512U CN 202122108857 U CN202122108857 U CN 202122108857U CN 215641512 U CN215641512 U CN 215641512U
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Abstract
The utility model provides a hand-held transformer direct-current resistance tester, which comprises a third dynamic switch, a first diode, an interface board, a discharge board, an MCU (microprogrammed control unit) main control board, a sampling board, a power supply, a first capacitor, a first active capacitor, a first field effect transistor, a dynamic switch and a power supply board, wherein the third dynamic switch is connected with the first diode; the MCU main control board comprises an MCU main control chip and a signal conditioning circuit, the sampling board is connected with the signal conditioning circuit so as to send the acquired signals to the signal conditioning circuit, the signal conditioning circuit sends the conditioned signals to the MCU main control chip, and the power supply is respectively connected with the MCU main control board and the power supply board; the four-wire resistance measuring device is small in size, convenient to carry and measure, high in measuring accuracy due to the adoption of a four-wire resistance measuring method, greatly reduces the burden of workers and saves more manpower and material resources.
Description
Technical Field
The utility model relates to the technical field of direct current resistance testing, in particular to a handheld transformer direct current resistance tester.
Background
A transformer direct current resistance tester, which is called a direct current resistance tester for short, is a device for measuring direct current resistance of a transformer winding and a high-power inductance device, and the traditional transformer direct current resistance tester has a large volume and is inconvenient for workers to carry, as shown in fig. 1, the traditional direct method for measuring resistance is to measure the resistance of a tested part by adopting an ohmmeter, but actually, the resistance measured by the ohmmeter is the sum of all resistances on the whole measurement loop, namely the resistance of an electric wire connecting the ohmmeter and the tested part and the resistance of the tested part, and if a connecting lead is long, the resistance of the tested part is very low, and a measurement error introduced by the resistance of the lead is very large; meanwhile, the interference factors of the transformer are more, so that the interference on signals collected by the direct current resistance tester is more, the interference on the signals collected by the direct current resistance tester is more, the measurement error is larger, and accurate measurement data cannot be acquired.
SUMMERY OF THE UTILITY MODEL
The object of the present invention is to solve at least one of the technical drawbacks.
Therefore, one objective of the present invention is to provide a hand-held transformer dc resistance tester, which includes a third dynamic switch, a first diode, an interface board, a discharging board, an MCU main control board, a sampling board, a power supply, a first capacitor, a first active capacitor, a first fet, a dynamic switch and a power board; the MCU main control board comprises an MCU main control chip and a signal conditioning circuit, the sampling board is connected with the signal conditioning circuit to send collected signals to the signal conditioning circuit, the signal conditioning circuit sends conditioned signals to the MCU main control chip, the power supply is respectively connected with the MCU main control board and the power supply board, and the sampling board comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a first dynamic break switch and a second dynamic break switch.
The positive terminal of the interface board is connected with the positive terminal of the discharge board and one end of the movable switch, the negative terminal of the interface board is grounded with the negative terminal of the discharge board and the negative terminal of the first polar capacitor, the positive terminal of the first polar capacitor is connected with the other end of the movable switch through the third movable break switch, the second movable break switch is connected with the first resistor in parallel, one end of the second movable break switch in parallel is connected with the other end of the movable switch, the other end of the second movable break switch in parallel is connected with one end of the second resistor, one end of the first movable break switch in parallel is connected with the other end of the second resistor, the other end of the fourth resistor in parallel is connected, the source electrode of the first field effect tube is connected with the positive electrode of the first diode and one end of the first capacitor, the grid electrode of the first field effect tube is connected with the negative electrode of the first diode and the other end of the first capacitor, the drain electrode of the first field effect tube is connected with the positive terminal of the power supply board, the negative end of the power panel is grounded.
Preferably, the signal conditioning circuit includes a second capacitor, a second active capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, an adjustable resistor, a digital potentiometer, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a dual operational amplifier, a first operational amplifier, a second diode, a triode, a first relay, a second relay, a third relay, a fourth relay, and a second field effect transistor; one end of a second capacitor is grounded with the anode of the second polar capacitor, the other end of the second capacitor is connected with the cathode of the second polar capacitor and one end of an adjustable resistor, the other end of the adjustable resistor is connected with a low-voltage end pin of a digital potentiometer, a sliding end pin of the digital potentiometer is connected with the equidirectional input end of a double operational amplifier through a fifth resistor, the output end of the double operational amplifier is connected with one end of a switch end of a first relay, the base electrode of a triode is connected with one end of a sixth resistor, the emitter electrode of the triode is grounded, the collector electrode of the triode is connected with a coil end of the first relay, one end of a seventh resistor and one end of an eighth resistor are respectively connected with the other end of the switch of the first relay, one end of a ninth resistor is connected with the other end of the seventh resistor, the other end of the eighth resistor, one end of a tenth resistor and one end of the fifth capacitor, the other end of the tenth resistor is grounded through a fourth capacitor, the other end of the ninth resistor is connected with the reverse input end of the first operational amplifier and one end of the third capacitor, the other end of the third capacitor is connected with the output end of the first operational amplifier and one end of the eleventh resistor, the other end of the eleventh resistor is connected with one end of the sixth capacitor and the cathode of the second diode and the grid of the second field-effect tube through the twelfth resistor, the source of the second field-effect tube is connected with the anode of the second diode, the other end of the sixth capacitor is connected with one end of the second relay switch, the other end of the second relay switch is connected with one end of the fourteenth resistor, the other end of the fourteenth resistor is connected with one end of the third relay switch through the thirteenth resistor, and the other end of the third relay switch is connected with one end of the fourth relay switch.
In any of the above schemes, the mobile phone further comprises a USB interface, a charging port, a liquid crystal screen and a key, wherein the USB interface, the charging port, the liquid crystal screen and the key are respectively connected with the MCU main control board.
In any of the above schemes, preferably, 6 test current gears of 10A, 3A, 1A, 300mA, 100mA and 5mA on the display screen are selected by keys to select the current required by the transformer winding.
Compared with the prior art, the utility model has the beneficial effects that:
1. the utility model has small volume, is convenient to carry and measure, greatly reduces the burden of workers and saves more manpower and material resources.
2. The sampling board collects current signals of a transformer winding through a current interface on the interface board, conditions the signals through the signal conditioning circuit, sends the conditioned signals to the MCU main control chip, and the MCU main control chip collects voltage signals of the transformer winding through a voltage interface on the interface board, so that the direct-current resistance of the transformer is calculated, and the measurement precision is high.
3. The utility model adopts the four-wire method measuring principle, two current wiring ports and two voltage wiring ports are directly led out from the interior of the hand-held transformer direct current resistance tester, the two current wiring ports and the two voltage wiring ports are connected through the wiring ports and respectively clamped on the two sides of the tested component, the resistance of the tested component can be determined by measuring the current passing through the component and the voltage drop passing through the component, the measurement is simple and convenient, the measured data is accurate, and the labor is saved.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
fig. 1 is a schematic circuit diagram of a conventional resistance measurement method.
FIG. 2 is a block diagram of a hand-held transformer DC resistance tester according to the present invention;
FIG. 3 is a block diagram of the circuit structure of a hand-held transformer DC resistance tester according to the present invention;
FIG. 4 is a schematic circuit diagram of a hand-held transformer DC resistance tester according to the present invention;
fig. 5 is a schematic circuit diagram of a signal conditioning circuit in the MCU main control board shown in fig. 3 according to the present invention;
fig. 6 is a schematic diagram of a hand-held transformer dc resistance tester measuring resistance according to the present invention.
Wherein the reference numbers:
1-interface board, 2-discharge board, 3-main control board, 4-power supply, 5-sampling board, 6-power supply board, 7-USB interface, 8-charging port, 9-liquid crystal screen, 10-key, 11-current binding post and 12-voltage binding post.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the utility model and are not to be construed as limiting the utility model.
As shown in fig. 2, 3 and 4, a hand-held transformer dc resistance tester according to a preferred embodiment of the present invention includes a third dynamic cut-off switch K3, a first diode D1, an interface board 1, a discharge board 2, an MCU main control board 3, a sampling board 5, a power supply 4, a first capacitor C1, a first polar capacitor C2, a first fet M1, a dynamic on-off switch KM1, and a power supply board 6; MCU main control board 3 includes MCU main control chip and signal conditioning circuit, sampling board 5 is connected with signal conditioning circuit, with by the signal transmission to signal conditioning circuit with gathering, signal conditioning circuit sends the MCU main control chip with the signal after the regulation, power 4 is connected with MCU main control board 3 and power strip 6 respectively, sampling board 5 includes first resistance R1, second resistance R2, third resistance R3, fourth resistance R4, first disconnected switch K1 and second disconnected switch K2.
The positive terminal of the interface board 1 is connected with the positive terminal of the discharge plate 2 and one end of the dynamic switch KM1, the negative terminal of the interface board 1 is connected with the negative terminal of the discharge plate 2 and the negative terminal of the first active capacitor C2 to ground, the positive terminal of the first active capacitor C2 is connected with the other end of the dynamic switch KM1 through the third dynamic switch K3, the second dynamic switch K2 is connected in parallel with the first resistor R1, the parallel end of the second active switch K1 is connected with the other end of the dynamic switch KM1, the parallel end of the second active switch K2 is connected with one end of the second resistor R2, the first dynamic switch K1 is connected in parallel with the third resistor R3, the parallel end of the second resistor R2 is connected with the other end of the second resistor R4, the source of the first field effect transistor M1 is connected with the positive terminal of the first diode D1 and one end of the first capacitor C1, the gate of the first field effect transistor M1 is connected with the negative terminal of the first diode D1 and the first capacitor C1, the drain of the first field effect transistor M1 is connected to the positive terminal of the power supply board 6, and the negative terminal of the power supply board 6 is grounded.
The utility model discloses small, conveniently carry, can alleviate staff's burden, hand-held type transformer direct current resistance tester discharges through discharge panel 2 after the measuring resistance is accomplished, the safety of each part circuit of protection instrument.
Further, as shown in fig. 5, the signal conditioning circuit includes a second capacitor C12, a second active capacitor E3, a third capacitor C5, a fourth capacitor C6, a fifth capacitor C7, a sixth capacitor C11, an adjustable resistor W1, a digital potentiometer U5, a fifth resistor R13, a sixth resistor R11, a seventh resistor R8, an eighth resistor R9, a ninth resistor R6, a tenth resistor R7, an eleventh resistor R5, a twelfth resistor R41, a thirteenth resistor R10, a fourteenth resistor R20, a dual operational amplifier U3A, a first operational amplifier U1, a second diode D11, a triode Q2, a first relay K31, a second relay K21, a third relay K11, a fourth relay K41, and a second field effect transistor M11; one end of a second capacitor C12 and the anode of the second active capacitor E3 are grounded, the other end of the second capacitor C12 is connected with the cathode of the second active capacitor E3 and one end of an adjustable resistor W1, the other end of the adjustable resistor W1 is connected with a low-voltage end VL pin of a digital potentiometer U5, and a sliding end V of the digital potentiometer U5 is connected with a voltage source VWThe pin is connected with the equidirectional input end of a dual operational amplifier U3A through a fifth resistor R13, the output end of the dual operational amplifier U3A is connected with one end of the switch end of a first relay K31, the base of a triode Q2 is connected with one end of a sixth resistor R11, the emitter of a triode Q2 is grounded, the collector of the triode Q2 is connected with the coil end of the first relay K31, one end of a seventh resistor R8 and one end of an eighth resistor R9 are respectively connected with the other end of the switch of the first relay K31, one end of a ninth resistor R6 is connected with the other end of the seventh resistor R8, the other end of the eighth resistor R9, one end of a tenth resistor R7 and one end of a fifth capacitor C7, the other end of the tenth resistor R7 is grounded through a fourth capacitor C6, and a ninth resistor R6The other end of the third resistor R5 is connected to one end of a twelfth resistor R41, one end of a sixth capacitor C11, the negative electrode of a second diode D11 and the gate of a second field effect transistor M11, the source of the second field effect transistor M11 is connected to the positive electrode of a second diode D11, the other end of the sixth capacitor C11 and one end of a second relay K21 switch, the other end of the second relay K21 switch is connected to one end of a fourteenth resistor R20, the other end of the fourteenth resistor R20 is connected to one end of a third relay K11 switch through a thirteenth resistor R10, and the other end of the third relay K11 switch is connected to one end of a fourth relay K41 switch.
The signal conditioning circuit carries out noise removal processing on the collected current signals and converts the current signals into standard signals to be supplied to the MCU main control chip, 2, the MCU main control chip collects voltage signals of a transformer winding through a voltage interface on the interface board 1, and therefore the direct current resistance of the transformer is calculated; the measured data is more accurate and reliable.
Specifically, the device further comprises a USB interface 7, a charging port 8, a liquid crystal screen 9 and a key 10, wherein the USB interface 7, the charging port 8, the liquid crystal screen 9 and the key 10 are respectively connected with the MCU main control panel 3.
Further, 6 test current gears of 10A, 3A, 1A, 300mA, 100mA and 5mA on the display screen are selected through the key 10 so as to select the current required by the transformer winding.
Optionally, the MCU main control chip is an STM32F407 type chip.
The working process of the utility model is as follows: the current required by a transformer winding is selected by selecting 6 test current gears such as 10A, 3A, 1A, 300mA, 100mA, 5mA and the like displayed on a liquid crystal screen 9 through a key 10, the MCU main control board 3 outputs corresponding constant current to supply power to the transformer winding through a control power supply board 6, the sampling board 5 collects current signals of the transformer winding through a current wiring terminal 11 on an interface board 1, a signal conditioning circuit conditions and removes noise of the collected current signals and converts the signals into standard signals to send to an MCU main control chip, the MCU main control board 3 collects voltage signals of the transformer winding through a voltage wiring terminal 12 on the interface board 1, and the MCU main control board 3 calculates the direct current resistance of the transformer through the voltage signals and the current signals collected by the interface board 1.
The hand-held transformer direct current resistance tester adopts a four-wire method measurement principle, and the four-wire method measurement principle is as follows:
as shown in fig. 6, we know from ohm's law that the resistance is equal to the voltage divided by the current, i.e., R ═ U/I; therefore, two current wiring ports and two voltage wiring ports are directly led out from the interior of the hand-held transformer direct-current resistance tester, the two current wiring ports and the two voltage wiring ports are connected and respectively clamped on two sides of a tested component, and the current passing through the component and the voltage drop passing through the component are measured, so that the resistance value of the component can be measured.
The embodiment of the utility model has the advantages of simple and direct measurement mode, high measurement precision, portability and convenient use by workers. In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the principle and spirit of the present invention. The scope of the utility model is defined by the appended claims and equivalents thereof.
Claims (4)
1. The utility model provides a hand-held type transformer direct current resistance tester which characterized in that: the sampling circuit comprises a third dynamic break switch, a first diode, an interface board, a discharge board, an MCU (microprogrammed control unit) main control board, a sampling board, a power supply, a first capacitor, a first active capacitor, a first field effect transistor, a dynamic on-off switch and a power supply board; the sampling board comprises an MCU main control chip and a signal conditioning circuit, the sampling board is connected with the signal conditioning circuit to send collected signals to the signal conditioning circuit, the signal conditioning circuit sends conditioned signals to the MCU main control chip, the power supply is respectively connected with the MCU main control board and the power supply board, and the sampling board comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a first dynamic break switch and a second dynamic break switch; wherein:
the positive terminal of the interface board is connected with the positive end of the discharge plate and one end of the movable switch, the negative terminal of the interface board is grounded with the negative end of the discharge plate and the negative end of the first active capacitor, the positive electrode of the first active capacitor is connected with the other end of the movable switch through the third active switch, the second active switch is connected with the first resistor in parallel, one parallel end of the second active switch is connected with the other end of the movable switch, the other parallel end of the second active switch is connected with one end of the second resistor, the first active switch is connected with the third resistor in parallel, one parallel end of the first active switch is connected with the other end of the second resistor, the other parallel end of the first active switch is connected with one end of the fourth resistor, the source electrode of the first field effect tube is connected with the positive electrode of the first diode and one end of the first capacitor, and the gate electrode of the first field effect tube is connected with the negative electrode of the first diode and the other end of the first capacitor, the drain electrode of the first field effect tube is connected with the positive electrode end of the power panel, and the negative electrode end of the power panel is grounded.
2. The hand-held transformer dc resistance tester of claim 1, wherein: the signal conditioning circuit comprises a second capacitor, a second active capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, an adjustable resistor, a digital potentiometer, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a dual operational amplifier, a first operational amplifier, a second diode, a triode, a first relay, a second relay, a third relay, a fourth relay and a second field effect transistor; one end of the second capacitor is grounded with the anode of the second polar capacitor, the other end of the second capacitor is connected with the cathode of the second polar capacitor and one end of the adjustable resistor, the other end of the adjustable resistor is connected with a low-voltage end pin of the digital potentiometer, a sliding end pin of the digital potentiometer is connected with the equidirectional input end of the dual operational amplifier through the fifth resistor, the output end of the dual operational amplifier is connected with one end of the switch end of the first relay, the base electrode of the triode is connected with one end of the sixth resistor, the emitting electrode of the triode is grounded, the collector electrode of the triode is connected with the coil end of the first relay, one end of the seventh resistor and one end of the eighth resistor are respectively connected with the other end of the switch of the first relay, one end of the ninth resistor is connected with the other end of the seventh resistor, The other end of the eighth resistor, one end of the tenth resistor and one end of the fifth capacitor are connected, the other end of the tenth resistor is grounded through the fourth capacitor, the other end of the ninth resistor is connected with the inverting input end of the first operational amplifier and one end of the third capacitor, the other end of the third capacitor is connected with the output end of the first operational amplifier and one end of the eleventh resistor, the other end of the eleventh resistor is connected with one end of the sixth capacitor, the cathode of the second diode and the gate of the second field effect transistor through the twelfth resistor, the source of the second field effect transistor is connected with the anode of the second diode, the other end of the sixth capacitor and one end of the second relay switch, and the other end of the second relay switch is connected with one end of the fourteenth resistor, the other end of the fourteenth resistor is connected with one end of the third relay switch through the thirteenth resistor, and the other end of the third relay switch is connected with one end of the fourth relay switch.
3. The hand-held transformer dc resistance tester of claim 1, wherein: the MCU master control board is connected with the USB interface, the charging port, the liquid crystal display and the keys respectively.
4. A hand-held transformer dc resistance tester as claimed in claim 3, wherein: 6 test current gears of 10A, 3A, 1A, 300mA, 100mA and 5mA on the display screen are selected through the keys so as to select the current required by the transformer winding.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122108857.3U CN215641512U (en) | 2021-09-02 | 2021-09-02 | Hand-held transformer direct-current resistance tester |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122108857.3U CN215641512U (en) | 2021-09-02 | 2021-09-02 | Hand-held transformer direct-current resistance tester |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN215641512U true CN215641512U (en) | 2022-01-25 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202122108857.3U Active CN215641512U (en) | 2021-09-02 | 2021-09-02 | Hand-held transformer direct-current resistance tester |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN215641512U (en) |
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2021
- 2021-09-02 CN CN202122108857.3U patent/CN215641512U/en active Active
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