CN206609919U - Earth resistance tester - Google Patents
Earth resistance tester Download PDFInfo
- Publication number
- CN206609919U CN206609919U CN201720281828.8U CN201720281828U CN206609919U CN 206609919 U CN206609919 U CN 206609919U CN 201720281828 U CN201720281828 U CN 201720281828U CN 206609919 U CN206609919 U CN 206609919U
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- circuit
- current
- resistance
- measurement
- control
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Abstract
The utility model discloses a kind of earth resistance tester, including current regulation loop, the circuit of measurement and control being connected with power supply, the current regulation loop and circuit of measurement and control are connected with measured resistance, circuit of measurement and control is also connected with operation button and display panel, loop current is transferred to certain value and is added in measured resistance by the current regulation loop, circuit of measurement and control handles the signal at the end of measured resistance two, in combination with the state of operation button, at least alarmed, timing, display action, once alarming, loop current is switched off.
Description
Technical field
The utility model is related to resistance measurement art, refers in particular to a kind of earth resistance tester.
Background technology
Earth resistance tester is the Common Instrument for examining measurement of Grounding Resistance, is also electrical safety inspection and earth work
The indispensable instrument of final acceptance of construction, enters developing rapidly due to computer technology over year, therefore earth resistance tester also oozes
Substantial amounts of earth resistance tester Microprocessor technology thoroughly, currently advanced ground resistance meter can meet all earthmeters and want
Ask.But the function of common earth resistance tester is simple, safety in utilization is not high, is not suitable for most of occasions.
Utility model content
In view of this, in view of the existing deficiencies of the prior art, its main purpose is to provide a kind of security to the utility model
Can it is high, the earth resistance tester of measured piece resistance and test loop electric current can be shown with warning function and intuitively.
To achieve the above object, the utility model is using following technical scheme：
A kind of earth resistance tester, including current regulation loop, the circuit of measurement and control being connected with power supply, the electric current
Regulating loop and circuit of measurement and control are connected with measured resistance, and circuit of measurement and control is also with operating button and display panel phase
Even, loop current is transferred to certain value and is added in measured resistance by the current regulation loop, and circuit of measurement and control is measured resistance two
The signal at end is handled, in combination with operation button state, at least alarmed, timing, display action, once report
Alert, loop current is switched off.
As a kind of preferred scheme, the circuit structure of the current regulation loop includes switch mode voltage converters, ratio
Compared with device, error amplifier, PWM modulator, in operation, output current ix is detected by measured resistance first, then, using comparing
Device compares the electric current ix detected with reference current value Ix, ref, detected output current ix and reference current Ix, ref
Between difference be error, it is sent to error amplifier, next, the output of error amplifier is sent to PWM modulator,
The order of needs is sent to switching equipment to change/control the control parameter in power supply by PWM modulator, so as to change switching molding
The output voltage of formula voltage changer, therefore, output current ix can be efficiently controlled.
As a kind of preferred scheme, it is defeated that the circuit of measurement and control includes single chip machine controlling circuit, AD sample circuits, power supply
Go out circuit, the single chip machine controlling circuit controls power output circuit to provide measurement power supply, the AD samplings electricity to grounding resistance
Road gathers the measured parameter of grounding resistance, is additionally provided with pwm control circuit, and the pwm control circuit is carried out to power output circuit
Control the measurement power supply exported with regulation power supply output circuit.
As a kind of preferred scheme, the operation button and display panel are arranged at the front panel of earth resistance tester
On, the front panel is provided with power switch, start button, reset key, current adjusting knob, measured piece access interface, timing
Put several dial-up dish, timing display window, electric current display window, measured resistance display window, test indicator lamp, police instruction
Lamp, alarm selection key, test resistance selection key, time switch, preset/test button, the alarm preset adjusting knob of resistance.
The utility model has clear advantage and beneficial effect compared with prior art, specifically, by above-mentioned technology
Scheme understands that it, which is mainly, is provided with current regulation loop and circuit of measurement and control, and the current regulation loop adjusts loop current
It is added to certain value in measured resistance, circuit of measurement and control handles the signal at the end of measured resistance two, in combination with operation
The state of button, at least alarmed, timing, display action, once alarming, loop current is switched off.
More clearly to illustrate architectural feature of the present utility model and effect, come below in conjunction with the accompanying drawings with specific embodiment pair
The utility model is described in detail.
Brief description of the drawings
Fig. 1 is the structured flowchart of the earth resistance tester of the embodiment of the utility model.
Fig. 2 is the circuit structure diagram of current regulation loop in Fig. 1.
Fig. 3 is the circuit structure diagram of circuit of measurement and control in Fig. 1.
Fig. 4 is the front panel schematic diagram of the earth resistance tester of the embodiment of the utility model.
Accompanying drawing identifier declaration：
10th, power supply 20, current regulation loop
21st, switch mode voltage converters 22, comparator
23rd, error amplifier 24, PWM modulator
30th, circuit of measurement and control 31, single chip machine controlling circuit
32nd, AD sample circuits 33, power output circuit
34th, pwm control circuit 40, measured resistance
50th, operation button 60, display panel
70th, front panel 701, power switch
702nd, start button 703, reset key
704th, current adjusting knob 705, measured piece access interface
706th, several dial-up dish 707, timing display window are regularly put
708th, electric current display window 709, measured resistance display window
710th, test indicator lamp 711, alarm lamp
712nd, alarm selection key 713, test resistance selection key
714th, time switch 715, preset/test button
716th, the alarm preset adjusting knob of resistance.
Embodiment
It refer to shown in Fig. 1 to Fig. 4, be a kind of that show the concrete structure of the preferred embodiment of the utility model
Earth resistance tester, including current regulation loop 20, the circuit of measurement and control 30 being connected with power supply 10, the electric current are adjusted back
Road 20 and circuit of measurement and control 30 are connected with measured resistance 40, and circuit of measurement and control 30 is also with operating button 50 and display surface
Plate 60 is connected, and loop current is transferred to certain value and is added in measured resistance 40 by the current regulation loop 20, circuit of measurement and control 30
The signal at the end of measured resistance 40 2 is handled, in combination with operation button 50 state, at least alarmed, timing, show
Show action, once alarming, loop current is switched off.
Wherein, as shown in Fig. 2 the circuit structure of the current regulation loop 20 include switch mode voltage converters 21,
Comparator 22, error amplifier 23, PWM modulator 24, in operation, output current ix detect by measured resistance 40 first, with
Afterwards, using comparator 22 by the electric current ix detected and reference current value Ix, ref compares, detected output current ix with
Difference between reference current Ix, ref is error, and it is sent to error amplifier 23, next, the output of error amplifier 23
PWM modulator 24 is sent to, the order of needs is sent to switching equipment to change/control in power supply 10 by PWM modulator 24
Control parameter（Such as dutycycle or switching frequency）, so that change the output voltage of switch mode voltage converters 21, therefore,
Output current ix can be efficiently controlled.
As shown in figure 3, the circuit of measurement and control 30 is defeated including single chip machine controlling circuit 31, AD sample circuits 32, power supply
Go out circuit 33, the single chip machine controlling circuit 31 controls power output circuit 33 to provide measurement power supply 10 to grounding resistance, described
AD sample circuits 32 gather the measured parameter of grounding resistance, are additionally provided with pwm control circuit 34, described 34 pairs of electricity of pwm control circuit
Source follower circuit 33 is controlled the measurement power supply 10 exported with regulation power supply output circuit 33.34 pairs of pwm control circuit is set
Power output circuit 33 is controlled the measurement power supply 10 exported with regulation power supply output circuit 33, so, tests at the scene
When, measurement power supply 10 uses variable mode, exports the power supply 10 of frequency conversion, can eliminate the interference of electromagnetic field at scene, therefore
The data under power frequency 50Hz can be accurately measured under strong interference environment.
As shown in figure 4, the operation button 50 and display panel 60 are arranged on the front panel 70 of earth resistance tester,
The front panel 70 connects provided with power switch 701, start button 702, reset key 703, current adjusting knob 704, measured piece
Inbound port 705, regularly put several dial-up dish 706, timing display window 707, electric current display window 708, measured resistance and show
Window 709, test indicator lamp 710, alarm lamp 711, alarm selection key 712, test resistance selection key 713, time switch
714th, preset/test button 715, the alarm preset adjusting knob 716 of resistance.
The concrete function of each operation button 50 and display panel 60 is described as follows：
Power switch 701：Press this key power supply 10 to open, on the contrary then power supply 10 is closed.
Start button 702：Press the button once, test starts, test lamp is bright.
Reset key 703：Press the button once, loop current is just cut off, alarm acousto-optic can also fall clearly.
Current adjusting knob 704：The electric current that turned clockwise under test mode increases.
Measured piece access interface 705：Docked with dedicated testing wire.
Several dial-up dish 706 are put in timing：1~99s.
Timing display window 707：The fixed time test time is shown, unit is " S ".
Electric current display window 708：Unit is " A ".
Measured resistance display window 709：Unit is " m Ω ".
Test indicator lamp 710：This lamp is bright to represent that instrument enters test mode.
Alarm lamp 711：This lamp is bright to represent that measured resistance 40 is excessive more than setting value, or electric current.
Alarm selection key 712：Alarm is pressed, ejection is not alarmed.
Test resistance selection key 713：Press and select 200 m Ω, 600 m Ω are selected in ejection.
Time switch 714：Press as definition status, ejection not timing.
Preset/test button 715：Press for alarm resistance it is preset, eject as test mode.
The alarm preset adjusting knob 716 of resistance：After preset button is pressed, it is necessary to can set plus determining electric current upon actuation
Put resistance alarming value.
Earth resistance tester of the present utility model is using step：Plug in 10, change power switch 701, electric current
Back to zero is adjusted, reset key 703 is clicked, at this moment time and current window are shown " 0 ", resistance window shows " 1 " or represents to overflow
Go out.（In definition status, time window shows dial-up value）.Dedicated testing wire is connected, measured piece is connected.Then surveyed by measured object
Try technological requirement and select corresponding resistance range, preset resistance alarming value, timing length etc., the step of all settings all
After the completion of, when confirming that tested loop connection is good, start key is clicked, test lamp is bright, into test mode, slowly
Regulating loop electric current makes it arrive required current value, and what now resistance window was shown is exactly tested grounding resistance.In test
During as selection under non-alarm condition, the instrument need not reset can continuously crawl test equal conditions under measured object.
First by reset key after having tested, then electric current back to zero.If abnormal conditions in test process, then reset key is first pressed, then soon
Fast electric current back to zero.
In summary, design focal point of the present utility model is, it, which is mainly, is provided with current regulation loop 20 and measurement
Circuit 30 is controlled, loop current is transferred to certain value and is added in measured resistance 40 by the current regulation loop, circuit of measurement and control 30
The signal at the end of measured resistance 40 2 is handled, in combination with operation button 50 state, at least alarmed, timing, show
Show action, once alarming, loop current is switched off.This instrument can intuitively show grounding resistance and the test of measured piece
Loop current, aobvious to have display clear, high resolution, the advantages of error is small.Other instrument also has overcurrent warning function, can have
Effect protection measured piece is in operation（Such as instantaneous overcurrent）It will not damage.This instrument be widely used in electrotechnical apparatus, power line,
The security parameter test of cable etc. and various electronic and electrical equipments, while being also scientific research institution, quality supervision department
Indispensable testing equipment.
It is described above, only it is preferred embodiment of the present utility model, not technical scope of the present utility model is made
Any limitation, therefore every any trickle amendment made according to technical spirit of the present utility model to above example, equivalent change
Change with modification, in the range of still falling within technical solutions of the utility model.
Claims (4)
1. a kind of earth resistance tester, it is characterised in that：Including be connected with power supply current regulation loop, measurement control electricity
Road, the current regulation loop and circuit of measurement and control are connected with measured resistance, circuit of measurement and control also with operation button and
Display panel is connected, and loop current is transferred to certain value and is added in measured resistance by the current regulation loop, circuit of measurement and control handle
The signal at the end of measured resistance two is handled, in combination with operation button state, at least alarmed, timing, display action,
Once alarming, loop current is switched off.
2. earth resistance tester according to claim 1, it is characterised in that：The circuit structure of the current regulation loop
Including switch mode voltage converters, comparator, error amplifier, PWM modulator, in operation, output current ix first by
Measured resistance detects that then, using comparator by the electric current ix detected and reference current value Ix, ref compares, detected
Difference between output current ix and reference current Ix, ref is error, and it is sent to error amplifier, next, error is amplified
The output of device is sent to PWM modulator, and the order of needs is sent to switching equipment changing/controls power supply by PWM modulator
In control parameter, so as to change the output voltage of switch mode voltage converters, therefore, output current ix can be controlled effectively
System.
3. earth resistance tester according to claim 1, it is characterised in that：The circuit of measurement and control includes single-chip microcomputer
Circuit, AD sample circuits, power output circuit are controlled, the single chip machine controlling circuit controls power output circuit to grounding resistance
Measurement power supply is provided, the AD sample circuits gather the measured parameter of grounding resistance, be additionally provided with pwm control circuit, the PWM controls
Circuit processed is controlled the measurement power supply exported with regulation power supply output circuit to power output circuit.
4. earth resistance tester according to claim 1, it is characterised in that：The operation button and display panel are set
In on the front panel of earth resistance tester, the front panel is provided with power switch, start button, reset key, electric current regulation
Knob, measured piece access interface, regularly put several dial-up dish, timing display window, electric current display window, measured resistance and show
Window, test indicator lamp, alarm lamp, alarm selection key, test resistance selection key, time switch, it is preset/test button,
The alarm preset adjusting knob of resistance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720281828.8U CN206609919U (en) | 2017-03-22 | 2017-03-22 | Earth resistance tester |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720281828.8U CN206609919U (en) | 2017-03-22 | 2017-03-22 | Earth resistance tester |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN206609919U true CN206609919U (en) | 2017-11-03 |
Family
ID=60165511
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201720281828.8U Expired - Fee Related CN206609919U (en) | 2017-03-22 | 2017-03-22 | Earth resistance tester |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN206609919U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109765431A (en) * | 2019-01-08 | 2019-05-17 | 科华恒盛股份有限公司 | Resistance measuring circuit, temperature sensing circuit and charging gun |
| CN117128844A (en) * | 2023-09-01 | 2023-11-28 | 国网甘肃省电力公司电力科学研究院 | Power grid equipment coating detection method and detector |
-
2017
- 2017-03-22 CN CN201720281828.8U patent/CN206609919U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109765431A (en) * | 2019-01-08 | 2019-05-17 | 科华恒盛股份有限公司 | Resistance measuring circuit, temperature sensing circuit and charging gun |
| CN117128844A (en) * | 2023-09-01 | 2023-11-28 | 国网甘肃省电力公司电力科学研究院 | Power grid equipment coating detection method and detector |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20171103 |