CN103376365A - Impedance ground testing device and probe with same - Google Patents
Impedance ground testing device and probe with same Download PDFInfo
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- CN103376365A CN103376365A CN 201210128689 CN201210128689A CN103376365A CN 103376365 A CN103376365 A CN 103376365A CN 201210128689 CN201210128689 CN 201210128689 CN 201210128689 A CN201210128689 A CN 201210128689A CN 103376365 A CN103376365 A CN 103376365A
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- ground wire
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- resistance
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- Measurement Of Resistance Or Impedance (AREA)
Abstract
Disclosed is an impedance ground testing device. The impedance ground testing device is used for testing whether a ground wire of a probe is normal or not and comprises a grounding device, a constant current source, a voltage detection circuit and a master controller. The grounding device is used for enabling the ground wire to be grounded. The constant current source is used for outputting an output current to the ground wire, and the output current flows to the grounding device through the ground wire. The voltage detection circuit is used for testing an upper pressure drop of the ground wire. The master controller is electrically connected to the voltage detection circuit and is used for judging the size of the impedance ground of the ground wire according to the pressure drop of the ground wire tested by the voltage detection circuit and for correspondingly judging whether the ground wire can be normally used or not. The invention further relates to the probe with the impedance ground testing device.
Description
Technical field
The present invention relates to a kind of earth loop impedance test device and have the probe of this earth loop impedance test device.
Background technology
Probe generally is connected on the oscillograph and uses, and the electric signal that is used for being measured imports oscillograph.Probe generally comprises signal wire and ground wire, and when tested electronic component being carried out the electric signal measurement, ground wire needs grounding mostly.Yet probe is after repeatedly using, and its ground wire may produce wearing and tearing and normal ground connection.Owing to also there is not at present whether impaired device of a kind of ground wire that can directly test probe, in actual use, often cause the impaired probe of ground wire also to be continued on for measuring electric signal, so then cause easily inputting oscillographic electric signal and distortion occurs, affect test result.
Summary of the invention
For the problems referred to above, be necessary the earth loop impedance test that provides a kind of ground wire that can conveniently measure probe whether to damage.
In addition, also be necessary to provide a kind of probe with described earth loop impedance test device.
A kind of earth loop impedance test device, whether the ground wire that is used for test one probe is normal, and described earth loop impedance test device comprises:
Earthing device is used for described ground connection;
Constant current source is used for output one and outputs current to described ground wire, and described output current flows to described earthing device via described ground wire;
Voltage detecting circuit is used for testing pressure drop on the described ground wire;
Master controller is electrically connected to described voltage detecting circuit, and described master controller is used for judging according to the pressure drop of the described ground wire of described voltage detecting circuit test the impedance ground size of ground wire, thereby correspondingly judges whether ground wire can normally use.
A kind of probe comprises probe, probe, signal wire, ground wire and above-mentioned earth loop impedance test device, and described probe is used for being connected in a testing apparatus, and described probe is used for contacting with transmission of electric signals with the measuring point that is subjected to of tested electronic devices and components; The two ends of described signal wire are individually fixed in probe and the probe, and the electric signal of described probe collection transfers to described testing apparatus via described signal wire and probe; Described ground wire one end is fixed in the described probe and is electrically connected to described probe.
The earthing device of described earth loop impedance test device makes ground connection, constant current source is exported described output current and is made between ground wire and the ground and form current return, voltage detecting circuit detects the pressure drop on the ground wire, master controller judges that by the pressure drop on the ground wire thereby the impedance ground of described ground wire judges ground wire and whether damage, so, whether described earth loop impedance test device can test out easily ground wire and damage.
Description of drawings
Fig. 1 is the synoptic diagram of the probe of preferred embodiments of the present invention.
Fig. 2 is the functional block diagram of the earth loop impedance test device of preferred embodiments of the present invention.
Fig. 3 is the circuit connection diagram of the ground wire of the constant current source of earth loop impedance test device shown in Figure 2 and earthing device and probe shown in Figure 1.
Fig. 4 is the master controller of earth loop impedance test device shown in Figure 2 and the circuit connection diagram of voltage detecting circuit.
Fig. 5 is the master controller of earth loop impedance test device shown in Figure 2 and the circuit connection diagram of indicating device.
The main element symbol description
| |
100 |
| |
10 |
| |
20 |
| |
30 |
| |
40 |
| The |
50 |
| The earth loop |
60 |
| |
61 |
| The |
611 |
| Constant |
62 |
| |
63 |
| |
64 |
| |
65 |
| The adjustable |
621 |
| The first operational amplifier | U1 |
| The second operational amplifier | U2 |
| Difference amplifier | U3 |
| The first diode | D1 |
| The first light emitting diode | D2 |
| The second light emitting diode | D3 |
| The second diode | D4 |
| Hummer | BP1 |
| Triode | Q1 |
| Drive resistance | R1 |
| The first regulating resistance | R2 |
| The second regulating resistance | R3 |
| Filter resistance | R4 |
| Gain arranges resistance | R5 |
| Resistance | R6-R10 |
| Current-limiting resistance | R11-R13 |
| Power supply | VCC |
| Node | A、B |
| The voltage input pin | IN |
| Regulate pin | ADJ |
| Output pin | OUT |
| In- |
1、4、7 |
| |
2、5、8 |
| |
3、6、9 |
| Output current | Iout |
Following embodiment further specifies the present invention in connection with above-mentioned accompanying drawing.
Embodiment
See also Fig. 1 and Fig. 2, the probe 100 of preferred embodiments of the present invention comprises that probe 10, probe 20, signal wire 30, ground wire 40 and earth loop impedance test device 60(are as shown in Figure 2).Probe 10 is used for probe 100 is connected to a testing apparatus by these probe 100 acquisition test signals, such as the oscillograph (not shown); Probe 20 is used for contacting with the measuring point that is subjected to of a tested electronic devices and components (not shown), with transmission of electric signals.The two ends of signal wire 30 are individually fixed in probe 10 and the probe 20, and the two ends of signal wire 30 are electrically connected at respectively probe 10 and probe 20; The electric signal that probe 20 gathers is via signal wire 30 and pop one's head in and 10 transfer to described testing apparatus.Ground wire 40 1 ends are fixed in probe 10 and are electrically connected to probe 10, and the other end is stretched out by probe 20.
Earth loop impedance test device 60 comprises earthing device 61, constant current source 62, voltage detecting circuit 63, master controller 64 and indicating device 65.Constant current source 62, voltage detecting circuit 63, master controller 64 and indicating device 65 can be arranged in the probe 10.
See also Fig. 1 and Fig. 3, earthing device 61 is used for ground wire 40 ground connection.Earthing device 61 comprises driving resistance R 1 and the first ground clamp 611.Ground wire 40 is connected to the first ground clamp 611 with respect to the other end of probe 10 by driving resistance R 1.The first ground clamp 611 is used for being held on the ground wire of a circuit board (not shown), makes ground wire 40 ground connection with this.
Described constant current source 62 is used for providing a constant output current Iout to described ground wire 40.Constant current source 62 comprises adjustable current source chip 621, the first regulating resistance R2, the second regulating resistance R3, the first diode D1, filter resistance R4 and filter capacitor C1.Adjustable current source chip 621 comprises voltage input pin IN, regulates pin ADJ and output pin OUT.Voltage input pin IN is electrically connected to a power supply VCC; Output pin OUT is electrically connected to the anode of the first diode D1; Regulate the node between pin ADJ is electrically connected to output pin OUT and the first diode D1 by the first regulating resistance R2 the anode, be electrically connected to the negative electrode of the first diode D1 by the second regulating resistance R3.Node between the first diode D1 and the second regulating resistance R3 is electrically connected to ground wire 40 by filter resistance R4, to export described output current Iout to ground wire 40, described output current Iout flows to ground via ground wire 40, driving resistance R 1, thereby forms current return.Suppose that the electric current on the output pin OUT is I1, the electric current on the first regulating resistance R2 is I2, and the electric current on the second regulating resistance R3 is I3, and then the value of output current Iout is electric current I 1, I2 and I3 sum.By regulating the resistance of the first regulating resistance R2 and the second regulating resistance R3, get final product the size of regulation output electric current I out.The first diode D1 is used for reducing the temperature coefficient of constant current source 62.Filter capacitor C1 is electrically connected between the node and ground between filter resistance R4 and the ground wire 40.Filter capacitor C1 and filter resistance R4 consist of a RC filtering circuit.In the present embodiment, the model of adjustable current source chip 621 is LM334, is made by company of STMicw Electronics (STMicroelectronics).
See also Fig. 4, voltage detecting circuit 63 is used for the pressure drop on the test ground wire 40, and cooperates the impedance ground on the master controller 64 test ground wires 40.Voltage detecting circuit 63 comprises that the first operational amplifier U1, the second operational amplifier U2, difference amplifier U3, gain arrange resistance R 5 and resistance R 6-R10.The in-phase input end 1 of the first operational amplifier U1 is electrically connected to the node of ground wire 40 and constant current source 62, such as the node A among Fig. 3; The in-phase input end of the second operational amplifier U2 is electrically connected to the node between ground wire 40 and the earthing device 61, such as the Node B among Fig. 3; The inverting input 2 of the first operational amplifier U1 and the second operational amplifier U2,5 arranges resistance R 5 by gain and is connected together.The output terminal 3 of the first operational amplifier U1 is electrically connected to inverting input 8, the second operational amplifier U2 of difference amplifier U3 by resistance R 8 output terminal 6 is electrically connected to the in-phase input end 7 of difference amplifier U3 by resistance R 9.Resistance R 6 is electrically connected between the output terminal 3 and inverting input 2 of the first operational amplifier U1; Resistance R 7 is electrically connected between the output terminal 6 and inverting input 5 of the second operational amplifier U2; Resistance R 10 is electrically connected between the output terminal 9 and inverting input 8 of difference amplifier U3.
The first operational amplifier U1 and the second operational amplifier U2 form symmetrical in-phase amplifier, and the voltage that is respectively applied to earth wire 40 two ends amplifies, and the voltage after will amplifying exports respectively inverting input 8 and the in-phase input end 7 of difference amplifier U3 to.Difference amplifier U3 exports master controller 64 to after the difference of the voltage of the voltage of its in-phase input end 7 and inverting input 8 being amplified again.The enlargement factor of whole voltage detecting circuit 63 can arrange resistance R 5 by gain and regulate.After 64 analog voltage signals with difference amplifier U3 output of master controller carry out analog to digital conversion, divided by the value of described output current Iout and the enlargement factor of voltage detecting circuit 63, then can obtain the impedance ground value of ground wire 40.
See also Fig. 5, indicating device 65 comprises the first light emitting diode D2, the second light emitting diode D3, hummer BP1, triode Q1, current-limiting resistance R11-R13 and the second diode D4.The negative electrode of the first light emitting diode D2 and the second light emitting diode D3 is electrically connected to respectively the first control pin P1 and the second control pin P2 of master controller 64; The anode of the first light emitting diode D2 and the second light emitting diode D3 is electrically connected to described power supply VCC by current-limiting resistance R11 and current-limiting resistance R12 respectively.In the present embodiment, the first light emitting diode D2 is red light; The second light emitting diode D3 is green light.The base stage of triode Q1 is electrically connected to the 3rd control pin P3 of master controller 64 by current-limiting resistance R13; Grounded emitter; Collector is electrically connected to described power supply VCC by hummer BP1.The anode of the second diode D4 electrically is electrically connected to the collector of triode Q1 and the node between the hummer BP1, and negative electrode is electrically connected to described power supply VCC.The second diode D4 plays the afterflow protection to triode Q1.
The below describes the testing process that earth loop impedance test device 60 earth wires 40 detect in detail.
At first the first ground clamp 611 is held on the ground wire of a circuit board the described output current Iout of constant current source 62 outputs.When the analog voltage signal that receives when master controller 64 is non-vanishing, 64 of master controllers compare impedance ground value and a reference resistance value that calculates, if this impedance ground value is greater than this reference resistance value, illustrate that ground wire 40 imperfect earths are good, it is unavailable that master controller 64 is judged this ground wire 40, the first control pin P1 output low level (logical zero) of master controller 64 makes the first light emitting diode D2 shinny, the second control pin P2 output high level (logical one) the second light emitting diode D3 extinguishes, and the 3rd control pin P3 output high level makes hummer BP1 sounding alarm.Non-vanishing and the impedance ground value that calculates of the analog voltage signal that receives when master controller 64 is during less than this reference resistance value, it is damaged and can continue to use that 64 of master controllers are judged this ground wire 40, the first control pin P1 output high level of master controller 64 extinguishes the first light emitting diode D2, the second light emitting diode D3 is shinny for the second control pin P2 output low level, and the 3rd control pin P3 exports level makes not sounding of hummer BP1.And the analog voltage signal that receives when master controller 64 is when being zero, be that pressure drop on the ground wire 40 is when being zero, illustrate that described output current Iout does not flow to driving resistance R 1 via ground wire 40, the impedance ground of ground wire 40 is very large, ground wire 40 is close to off state, 64 of master controllers need not to calculate directly judge ground wire 40 impedance ground greater than described reference resistance value, ground wire 40 is unavailable, the first control pin P1 output low level (logical zero) of master controller 64 makes the first light emitting diode D2 shinny, the second control pin P2 output high level (logical one) the second light emitting diode D3 extinguishes, and the 3rd control pin P3 output high level makes hummer BP1 sounding alarm.
Be appreciated that probe 100 can also comprise one second ground clamp 50.The second ground clamp 50 is electrically connected to node between ground wire 40 and the driving resistance R 1 by wire (figure mark).When probe 100 is carrying out electric signal when test to tested electronic component, the second ground clamp 50 connects the ground wire of a circuit board and makes ground wire 40 ground connection.
The earthing device 61 of described earth loop impedance test device 60 makes ground wire 40 ground connection, the described output current Iout of constant current source 62 outputs flows to described earthing device 61 via ground wire 40, the pressure drop that voltage detecting circuit 63 detects on the ground wire 40, master controller 64 judges that by the pressure drop on the ground wire 40 thereby the impedance ground of described ground wire 40 judges ground wire 40 and whether damage, so, whether described earth loop impedance test device 60 can test out easily ground wire 40 and damage.
Claims (10)
1. whether an earth loop impedance test device is normal for the ground wire of test one probe, it is characterized in that described earth loop impedance test device comprises:
Earthing device is used for described ground connection;
Constant current source is used for output one and outputs current to described ground wire, and described output current flows to described earthing device via described ground wire;
Voltage detecting circuit is used for testing pressure drop on the described ground wire; And
Master controller is electrically connected to described voltage detecting circuit, and described master controller is used for judging according to the pressure drop of the described ground wire of described voltage detecting circuit test the impedance ground size of ground wire, thereby correspondingly judges whether ground wire can normally use.
2. earth loop impedance test device as claimed in claim 1, it is characterized in that: described earthing device comprises driving resistance and the first ground clamp, described driving resistance string is coupled between described ground wire and described the first ground clamp, described the first ground clamp grounding.
3. earth loop impedance test device as claimed in claim 1, it is characterized in that: described constant current source comprises power supply, adjustable current source chip, the first regulating resistance, the second regulating resistance and the first diode, and described adjustable current source chip comprises the voltage input pin, regulates pin and output pin; Described voltage input pin is electrically connected to described power supply; Described output pin is electrically connected to the anode of described the first diode; Described adjusting pin is electrically connected to the node between the anode of described output pin and described the first diode by described the first regulating resistance, and is electrically connected to the negative electrode of described the first diode by described the second regulating resistance; Node between described the first diode and the second regulating resistance is electrically connected to described ground wire, and exporting the described described ground wire that outputs current to, the resistance by regulating the first regulating resistance and the second regulating resistance is to regulate the size of described output current.
4. earth loop impedance test device as claimed in claim 3, it is characterized in that: described constant current source also comprises filter resistance and filter capacitor, and described filter resistance is electrically connected between the node and described ground wire between described the first diode and the second regulating resistance; Described filter capacitor is electrically connected between the node and ground between described filter resistance and the ground wire.
5. earth loop impedance test device as claimed in claim 1, it is characterized in that: described voltage detecting circuit comprises that the first operational amplifier, the second operational amplifier, difference amplifier and gain arrange resistance; The in-phase input end of described the first operational amplifier and the second operational amplifier is electrically connected to respectively the two ends of described current sense resistor, and the inverting input of described the first operational amplifier and the second operational amplifier arranges resistance by gain and is connected together; The output terminal of described the first operational amplifier is electrically connected to the anti-phase phase input end of described difference amplifier, and the output terminal of described the second operational amplifier is electrically connected to the in-phase input end of described difference amplifier; Described the first operational amplifier and the second operational amplifier form symmetrical in-phase amplifier, be respectively applied to the voltage at described current sense resistor two ends is amplified, and the voltage after will amplifying exports respectively inverting input and the in-phase input end of described difference amplifier to; Described difference amplifier exports described master controller to after the difference of the voltage of the voltage of its in-phase input end and inverting input being amplified again.
6. earth loop impedance test device as claimed in claim 1, it is characterized in that: described earth loop impedance test device also comprises indicating device, described indicating device comprises the first light emitting diode and the second light emitting diode that all is electrically connected to described master controller, when described master controller is judged described ground wire when undesired, described main controller controls the first light emitting diode is shinny, controls simultaneously the second light emitting diode and extinguishes; And judge described ground wire when normal when described master controller, and described main controller controls the first light emitting diode extinguishes, and it is shinny to control simultaneously the second light emitting diode.
7. earth loop impedance test device as claimed in claim 1, it is characterized in that: described earth loop impedance test device also comprises indicating device, described indicating device comprises the hummer that is electrically connected to described master controller, when described master controller is judged described ground wire when undesired, the described hummer sounding of described main controller controls.
8. earth loop impedance test device as claimed in claim 7, it is characterized in that: described indicating device also comprises triode and power supply, the base stage of described triode is by being electrically connected to described master controller; Grounded emitter; Collector is electrically connected to described power supply by described hummer, and whether the conducting of described master controller by the described triode of control and cut-off corresponding control described hummer sounding.
9. a probe comprises probe, probe, signal wire and ground wire, and described probe is used for being connected in a testing apparatus, and described probe is used for contacting with transmission of electric signals with the measuring point that is subjected to of tested electronic devices and components; The two ends of described signal wire are individually fixed in probe and the probe, and the electric signal of described probe collection transfers to described testing apparatus via described signal wire and probe; Described ground wire one end is fixed in the described probe and is electrically connected to described probe, and it is characterized in that: described probe also comprises each described earth loop impedance test device such as claim 1-8.
10. probe as claimed in claim 9, it is characterized in that: described probe also comprises the second ground clamp, described the second ground clamp is electrically connected to node between described ground wire and the described driving resistance by wire; When described probe is carrying out electric signal when test to a circuit board, described the second ground clamp is connected to the ground wire of described circuit board and makes described ground connection.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201210128689 CN103376365A (en) | 2012-04-28 | 2012-04-28 | Impedance ground testing device and probe with same |
| TW101116128A TW201344210A (en) | 2012-04-28 | 2012-05-07 | Grounded impedance testing apparatus and probe having same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201210128689 CN103376365A (en) | 2012-04-28 | 2012-04-28 | Impedance ground testing device and probe with same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN103376365A true CN103376365A (en) | 2013-10-30 |
Family
ID=49461788
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201210128689 Pending CN103376365A (en) | 2012-04-28 | 2012-04-28 | Impedance ground testing device and probe with same |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN103376365A (en) |
| TW (1) | TW201344210A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104749476A (en) * | 2013-12-25 | 2015-07-01 | 国家电网公司 | Grounding detection device and grounding detection method |
| CN106154046A (en) * | 2015-04-27 | 2016-11-23 | 台达电子工业股份有限公司 | Impedance ground detection device |
| CN107907745A (en) * | 2017-12-31 | 2018-04-13 | 广东立信防雷科技有限公司 | A kind of earth resistance tester and its grounding monitor method |
| CN108051615A (en) * | 2017-12-29 | 2018-05-18 | 国家电网公司 | A kind of detection type tester ground wire |
| CN110412355A (en) * | 2018-04-28 | 2019-11-05 | 武汉市康达电气有限公司 | A kind of earth loop impedance test instrument |
| CN110988737A (en) * | 2019-12-13 | 2020-04-10 | 深圳市迅科达智能科技有限公司 | Equipment ground wire monitoring device |
| CN111901586A (en) * | 2020-07-29 | 2020-11-06 | 重庆市天实精工科技有限公司 | Camera grounding intelligent test system and method |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI553318B (en) * | 2014-11-18 | 2016-10-11 | 台達電子工業股份有限公司 | Grounding resistance measurement apparatus and method of operating the same |
| TWI651173B (en) * | 2015-06-02 | 2019-02-21 | 吳俊杰 | A workbench grounding real time detection device |
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2012
- 2012-04-28 CN CN 201210128689 patent/CN103376365A/en active Pending
- 2012-05-07 TW TW101116128A patent/TW201344210A/en unknown
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104749476A (en) * | 2013-12-25 | 2015-07-01 | 国家电网公司 | Grounding detection device and grounding detection method |
| CN106154046A (en) * | 2015-04-27 | 2016-11-23 | 台达电子工业股份有限公司 | Impedance ground detection device |
| CN106154046B (en) * | 2015-04-27 | 2019-01-01 | 台达电子工业股份有限公司 | Impedance ground detection device |
| CN108051615A (en) * | 2017-12-29 | 2018-05-18 | 国家电网公司 | A kind of detection type tester ground wire |
| CN107907745A (en) * | 2017-12-31 | 2018-04-13 | 广东立信防雷科技有限公司 | A kind of earth resistance tester and its grounding monitor method |
| CN110412355A (en) * | 2018-04-28 | 2019-11-05 | 武汉市康达电气有限公司 | A kind of earth loop impedance test instrument |
| CN110988737A (en) * | 2019-12-13 | 2020-04-10 | 深圳市迅科达智能科技有限公司 | Equipment ground wire monitoring device |
| CN111901586A (en) * | 2020-07-29 | 2020-11-06 | 重庆市天实精工科技有限公司 | Camera grounding intelligent test system and method |
| CN111901586B (en) * | 2020-07-29 | 2021-12-10 | 重庆市天实精工科技有限公司 | Camera grounding intelligent test system and method |
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| Publication number | Publication date |
|---|---|
| TW201344210A (en) | 2013-11-01 |
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Application publication date: 20131030 |