CN204740058U - Electric -magnetic flow meter proper motion is to excitation coil's insulation resistance test circuit - Google Patents
Electric -magnetic flow meter proper motion is to excitation coil's insulation resistance test circuit Download PDFInfo
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- CN204740058U CN204740058U CN201520473027.2U CN201520473027U CN204740058U CN 204740058 U CN204740058 U CN 204740058U CN 201520473027 U CN201520473027 U CN 201520473027U CN 204740058 U CN204740058 U CN 204740058U
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- field coil
- insulation resistance
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Abstract
The utility model relates to an excitation coil's insulation resistance test circuit, its characterized in that: including first resistance, the vehicle charging control system further comprises a second resistor, an operational amplifier, the second operation amplifier, third resistance and fourth resistance, an operational amplifier wherein, the the magnification of second operation amplifier is 1, and an operational amplifier is high input impedance operational amplifier, the first end of first resistance links to each other with the constant current source, ground connection behind the second end connection excitation coil's of first resistance the insulation resistance, the second end of first resistance is connected with an operational amplifier's non inverting input end after connecting second resistance simultaneously, an operational amplifier's inverting input end is connected with the output, ground connection behind third resistance and the fourth resistance is connected respectively to an operational amplifier's output, the first end of fourth resistance is connected with the non inverting input of second operation amplifier end, the inverting input end of second operation amplifier is connected with the output, and be connected with the inside AD converting circuit input of electric -magnetic flow meter.
Description
Technical field
The utility model relates to a kind of electromagnetic flowmeter voluntarily to the insulation resistance test circuit of field coil.
Background technology
The energized circuit of electromagnetic flowmeter comprises: constant current source S, and the switch of four electronic component compositions and field coil L, shown in accompanying drawing 1.If desired excitation field, a method is that constant current source provides exciting current, and electromagnetic flowmeter control panel controls electronic switch K1, K4 conducting, then exciting current is from constant current source through electronic switch K1, flows through field coil B point by A point, forms loop to electronic switch K4.If need to produce contrary excitation field, then electromagnetic flowmeter control panel controls electronic switch K2, K3 conducting, and exciting current through electronic switch K3, flows through field coil A point by B point from constant current source S, forms loop to electronic switch K2.If electromagnetic flowmeter control panel makes four electronic switch not conductings, then field coil does not have exciting current to pass through, and electromagnetic flowmeter would not produce excitation field.Above-mentioned is the excitation principle of electromagnetic flowmeter.The good field coil that insulate can make the exciting current of electromagnetic flowmeter stablize, reliably, without any shunting, thus keep the accurate and stable of magnetic field intensity, therefore very large meaning has been tested to the insulation resistance of field coil, but a kind of insulation resistance test circuit of comparatively convenient and practical field coil is not provided in prior art.
Utility model content
Technical problem to be solved in the utility model is the insulation resistance test circuit providing a kind of convenient and practical field coil for above-mentioned prior art.
The utility model solves the problems of the technologies described above adopted technical scheme: a kind of electromagnetic flowmeter is voluntarily to the insulation resistance test circuit of field coil, it is characterized in that: comprise the first resistance, second resistance, first operational amplifier, second operational amplifier, 3rd resistance and the 4th resistance, wherein the first operational amplifier, the enlargement factor of the second operational amplifier is 1, and the first operational amplifier is high input impedance operational amplifier, the first end of the first resistance is connected with constant current source, second end of the first resistance is connected with the first end of the insulation resistance of field coil, second end ground connection of the insulation resistance of field coil, second end of the first resistance is also connected with the first end of the second resistance simultaneously, second end of the second resistance is connected with the in-phase input end of the first operational amplifier, the inverting input of the first operational amplifier is connected with the output terminal of the first operational amplifier, the output terminal of the first operational amplifier is connected with the first end of the 3rd resistance, second end of the 3rd resistance is connected with the first end of the 4th resistance, second end ground connection of the 4th resistance, the first end of the 4th resistance is connected with the in-phase input end of the second operational amplifier simultaneously, the inverting input of the second operational amplifier is connected with the output terminal of the second operational amplifier, the output terminal of the second operational amplifier is connected with the A/D change-over circuit input end of electromagnetic flowmeter inside.
As improvement, the utility model also comprises the first diode and the second diode, wherein the negative pole of the first diode is connected with the first end of the insulation resistance of field coil, the positive pole of the first diode is connected with the negative pole of the second diode, and the positive pole of the second diode is connected with the second end of the insulation resistance of field coil.First diode and the second diode carry out in parallel with the insulation resistance of field coil; its Main Function protects the electronic switch in field coil and energized circuit; and the selection of the first diode and the second diode should ensure electronic switch conducting moment in energized circuit and disconnect the suppression by the first diode and the second diode of the high voltage pulse that produces instantaneously; thus realize protection field coil and electronic switch; and the first diode and the second diode, when electronic switch conducting, can not shunt the field power supply flowing through field coil.
Compared with prior art, the utility model has the advantage of: the circuit provided by the utility model, electromagnetic flowmeter can be made to test the insulation resistance of field coil voluntarily.
Accompanying drawing explanation
Fig. 1 is the energized circuit circuit diagram of electromagnetic flowmeter.
Fig. 2 is the circuit theory diagrams of the insulation resistance test circuit of field coil in the utility model embodiment.
Embodiment
Below in conjunction with accompanying drawing embodiment, the utility model is described in further detail.
A kind of electromagnetic flowmeter is as shown in Figure 2 voluntarily to the insulation resistance test circuit of field coil, it comprises the first resistance R1, second resistance R2, first operational amplifier U1, second operational amplifier U2, 3rd resistance R3 and the 4th resistance R4, wherein the first operational amplifier U1, the enlargement factor of the second operational amplifier U2 is 1, and the first operational amplifier U1 is high input impedance operational amplifier, the first end of the first resistance R1 and constant current source S-phase connect, second end of the first resistance R1 is connected with the first end of the insulation resistance RM of field coil, the second end ground connection of the insulation resistance RM of field coil, second end of the first resistance R1 is also connected with the first end of the second resistance R2 simultaneously, second end of the second resistance R2 is connected with the in-phase input end of the first operational amplifier U1, the inverting input of the first operational amplifier U1 is connected with the output terminal of the first operational amplifier U1, the output terminal of the first operational amplifier U1 is connected with the first end of the 3rd resistance R3, second end of the 3rd resistance R3 is connected with the first end of the 4th resistance R4, the second end ground connection of the 4th resistance R4, the first end of the 4th resistance R4 is connected with the in-phase input end of the second operational amplifier U2 simultaneously, the inverting input of the second operational amplifier U2 is connected with the output terminal of the second operational amplifier U2, the output terminal of the second operational amplifier U2 is connected with the A/D change-over circuit input end of electromagnetic flowmeter inside.
The present embodiment also comprises the first diode D1 and the second diode D2, wherein the negative pole of the first diode is connected with the first end of the insulation resistance of field coil, the positive pole of the first diode is connected with the negative pole of the second diode, and the positive pole of the second diode is connected with the second end of the insulation resistance of field coil.First diode and the second diode carry out in parallel with the insulation resistance of field coil; its Main Function protects the electronic switch in field coil and energized circuit; and the selection of the first diode and the second diode should ensure electronic switch conducting moment in energized circuit and disconnect the suppression by the first diode and the second diode of the high voltage pulse that produces instantaneously; thus realize protection field coil and electronic switch; and the first diode and the second diode, when electronic switch conducting, can not shunt the field power supply flowing through field coil.
Electromagnetic flowmeter control panel control four electronic switches K1, K2, K3, K4 not conducting time test field coil L insulation resistance RM, if the insulation resistance RM of field coil L declines, the insulation resistance RM of the first resistance R1 and field coil L is to supply voltage VS dividing potential drop, and namely B point current potential is VM, obviously
because VS and R1 is known, then can be obtained the insulation resistance RM of field coil L by test VM.Then the detection voltage of the A/D change-over circuit input end of electromagnetic flowmeter inside is often at 0 ~+2.5V, and the value of VM exceedes+2.5V usually, exceed the upper limit of detection of the A/D change-over circuit of electromagnetic flowmeter inside, and the conducting of electronic switch K1 ~ K4 moment and disconnection will produce high voltage pulse instantaneously, though this pulse is by over-voltage protection element---the first diode D1 and the second diode D2 suppresses, but still may exceed the nominal input range of the first operational amplifier; Therefore the second resistance is protective resistance; due to the homophase operational amplifier that the first operational amplifier U1 is high input impedance; and enlargement factor is 1; therefore the first operational amplifier U1 in-phase input end voltage approximates VM; first operational amplifier U1 output end voltage also approximates VM; the voltage that the A/D change-over circuit input end of electromagnetic flowmeter inside detects is V0
enlargement factor due to the second operational amplifier U2 is 1,3rd resistance and the 4th resistance are to the second operational amplifier U2 dividing potential drop, to ensure that the dynamic range of the second operational amplifier U2 output voltage V0 is in the input range of A/D change-over circuit, the second operational amplifier U2 is the same with the first operational amplifier U1 plays impedance matching effect.As the in-phase amplifier of high input impedance, V0=V
r4, the V0 therefore by recording, can calculate the insulation resistance RM of field coil L.
Claims (2)
1. an electromagnetic flowmeter is voluntarily to the insulation resistance test circuit of field coil, it is characterized in that: comprise the first resistance, second resistance, first operational amplifier, second operational amplifier, 3rd resistance and the 4th resistance, wherein the first operational amplifier, the enlargement factor of the second operational amplifier is 1, and the first operational amplifier is high input impedance operational amplifier, the first end of the first resistance is connected with constant current source, second end of the first resistance is connected with the first end of the insulation resistance of field coil, second end ground connection of the insulation resistance of field coil, second end of the first resistance is also connected with the first end of the second resistance simultaneously, second end of the second resistance is connected with the in-phase input end of the first operational amplifier, the inverting input of the first operational amplifier is connected with the output terminal of the first operational amplifier, the output terminal of the first operational amplifier is connected with the first end of the 3rd resistance, second end of the 3rd resistance is connected with the first end of the 4th resistance, second end ground connection of the 4th resistance, the first end of the 4th resistance is connected with the in-phase input end of the second operational amplifier simultaneously, the inverting input of the second operational amplifier is connected with the output terminal of the second operational amplifier, the output terminal of the second operational amplifier is connected with the A/D change-over circuit input end of electromagnetic flowmeter inside.
2. insulation resistance test circuit according to claim 1, it is characterized in that: also comprise the first diode and the second diode, wherein the negative pole of the first diode is connected with the first end of the insulation resistance of field coil, the positive pole of the first diode is connected with the negative pole of the second diode, and the positive pole of the second diode is connected with the second end of the insulation resistance of field coil.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520473027.2U CN204740058U (en) | 2015-06-30 | 2015-06-30 | Electric -magnetic flow meter proper motion is to excitation coil's insulation resistance test circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520473027.2U CN204740058U (en) | 2015-06-30 | 2015-06-30 | Electric -magnetic flow meter proper motion is to excitation coil's insulation resistance test circuit |
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| Publication Number | Publication Date |
|---|---|
| CN204740058U true CN204740058U (en) | 2015-11-04 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201520473027.2U Active CN204740058U (en) | 2015-06-30 | 2015-06-30 | Electric -magnetic flow meter proper motion is to excitation coil's insulation resistance test circuit |
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| CN (1) | CN204740058U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10712184B1 (en) | 2019-01-09 | 2020-07-14 | Georg Fischer Signet Llc | Magnetic flowmeter assembly having independent coil drive and control system |
| CN113624306A (en) * | 2021-09-06 | 2021-11-09 | 宁波水表(集团)股份有限公司 | Fault detection device and method for electromagnetic water meter sensor |
| US11365995B2 (en) | 2018-09-28 | 2022-06-21 | Georg Fischer Signet Llc | Magnetic flowmeter including auxiliary electrodes upstream and downstream of the pair of measuring electrodes and an adjustable brace |
-
2015
- 2015-06-30 CN CN201520473027.2U patent/CN204740058U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11365995B2 (en) | 2018-09-28 | 2022-06-21 | Georg Fischer Signet Llc | Magnetic flowmeter including auxiliary electrodes upstream and downstream of the pair of measuring electrodes and an adjustable brace |
| US10712184B1 (en) | 2019-01-09 | 2020-07-14 | Georg Fischer Signet Llc | Magnetic flowmeter assembly having independent coil drive and control system |
| CN113624306A (en) * | 2021-09-06 | 2021-11-09 | 宁波水表(集团)股份有限公司 | Fault detection device and method for electromagnetic water meter sensor |
| CN113624306B (en) * | 2021-09-06 | 2023-11-14 | 宁波水表(集团)股份有限公司 | Fault detection device and method for electromagnetic water meter sensor |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20200824 Address after: 315181 Lin village, Haishu District, Ningbo, Zhejiang Patentee after: NINGBO DONGHAI Group Corp. Address before: 315181, Zhejiang, Ningbo province Yinzhou District Heng Lin Village Patentee before: NINGBO DONGHAI INSTRUMENT WATERWAY Co.,Ltd. |
|
| TR01 | Transfer of patent right | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Assignee: NINGBO DONGHAI INSTRUMENT WATERWAY Co.,Ltd. Assignor: NINGBO DONGHAI Group Corp. Contract record no.: X2021330000081 Denomination of utility model: An insulation resistance test circuit of electromagnetic flowmeter to excitation coil Granted publication date: 20151104 License type: Exclusive License Record date: 20210819 |
|
| EE01 | Entry into force of recordation of patent licensing contract |