CN106353632B - Short-circuit fault detection circuit with low internal resistance load - Google Patents
Short-circuit fault detection circuit with low internal resistance load Download PDFInfo
- Publication number
- CN106353632B CN106353632B CN201610758520.8A CN201610758520A CN106353632B CN 106353632 B CN106353632 B CN 106353632B CN 201610758520 A CN201610758520 A CN 201610758520A CN 106353632 B CN106353632 B CN 106353632B
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- circuit
- external
- comparator
- short
- fault detection
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S10/00—Systems supporting electrical power generation, transmission or distribution
- Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
- Y04S10/52—Outage or fault management, e.g. fault detection or location
Abstract
The invention relates to the field of fault detection circuits, in particular to a short-circuit fault detection circuit with low internal resistance load, which can effectively reduce the volume of the circuit and has low cost, no false start and other phenomena, and comprises an external circuit, wherein one end of the external circuit is connected with an external power supply, the other end of the external circuit is connected with a voltage reduction circuit, the external circuit comprises an external load and a contact switch, the voltage reduction circuit is connected with a floating comparison reference circuit, a switching circuit and a first input end of a comparator, the floating comparison reference circuit is connected with a second input end of the comparator, the switching circuit is connected with a third input end of the comparator through a sampling circuit, the switching circuit is also connected with an isolated pulse trigger circuit, and an output end of the comparator is connected with an external main circuit through a fault signal output circuit.
Description
Technical Field
The invention relates to the field of fault detection circuits, in particular to a short-circuit fault detection circuit with low internal resistance load.
Background
The fire alarm system is a necessary facility in the building, public place and other places at present, can detect the fire occurrence and implement the warning, effectively guarantees personal and property safety of people, generally can monitor external load, needs to send out fault signal when the circuit of external load takes place to short-circuit or break line trouble, and the short-circuit trouble alarming function of low internal resistance load can not be realized well to current circuit, and phenomenon such as no start will appear in case of circuit short circuit, and generally requires to increase circuit power, and the volume of device is great, and is with high costs. Is not easy to realize.
Disclosure of Invention
In order to solve the problems, the invention provides a short-circuit fault detection circuit with low internal resistance load, which can effectively reduce the volume of the circuit, has low cost and can not generate the phenomena of false start and the like.
The technical scheme is as follows: the utility model provides a short circuit fault detection circuit of low internal resistance load, its includes external circuit, external power supply is connected to external circuit one end, the buck circuit is connected to the other end, external circuit includes external load and contact switch, buck circuit connects the first input of floating comparison reference circuit, switch circuit and comparator, floating comparison reference circuit connects the second input of comparator, switch circuit passes through sampling circuit to be connected the third input of comparator, switch circuit still connects isolation pulse trigger circuit, the output of comparator passes through fault signal output circuit and connects outer main circuit.
It is further characterized in that the step-down circuit comprises a rectifier bridge D3, a diode D1 and a diode D2;
the switching circuit comprises a triode T1;
the isolation pulse trigger circuit comprises an optocoupler U3 and a resistor R7;
the fault signal output circuit includes an optocoupler U1.
After the structure of the invention is adopted, a pulse triggering detection mode is adopted, the characteristic of extremely strong instant overload capacity of the device is utilized, the power of a sampling circuit is greatly reduced, the circuit volume is reduced, the cost is reduced, half of the normal working voltage of an external load is taken as the detection voltage, and the false action is avoided by adopting the pulse detection mode; after the optical coupler is adopted, the anti-interference performance is greatly improved.
Drawings
FIG. 1 is a schematic block diagram of the present invention;
fig. 2 is a schematic circuit diagram of the present invention.
Detailed Description
Referring to fig. 1, a short-circuit fault detection circuit with a low internal resistance load comprises an external circuit, wherein one end of the external circuit is connected with an external power supply, the other end of the external circuit is connected with a voltage reduction circuit, the external circuit comprises an external load and a contact switch, the voltage reduction circuit is connected with a floating comparison reference circuit, a switch circuit and a first input end of a comparator, the floating comparison reference circuit is connected with a second input end of the comparator, the switch circuit is connected with a third input end of the comparator through a sampling circuit, the switch circuit is further connected with an isolation pulse trigger circuit, and an output end of the comparator is connected with an external main circuit through a fault signal output circuit.
The specific circuit diagram is shown in fig. 2, wherein the voltage reduction circuit comprises a rectifier bridge D3, a diode D1 and a diode D2; the switching circuit comprises a triode T1; the isolation pulse trigger circuit comprises an optocoupler U3 and a resistor R7; the fault signal output circuit includes an optocoupler U1.
The working principle is as follows: the switching circuit is controlled by a trigger pulse signal which is detected at fixed time and is given by the isolation pulse trigger circuit, when the switching circuit is opened, the current of an external power supply flows into the sampling circuit through the voltage reduction circuit to reach an external load, voltage is generated on the sampling resistor R4, a signal is output to the main circuit after the voltage is compared with the voltage division of the floating comparison reference circuit on the resistor R2 through the comparator U2A, when the load is in short circuit, the current is increased, the voltage on the resistor R4 is increased to exceed the comparison threshold reference voltage, and the output level of the comparator U2A is the output fault signal.
The invention also has the following characteristics:
1. the wide voltage works, in order to work normally in a certain voltage range, a comparator in the circuit adopts a reference source which floats along with external voltage instead of a voltage stabilizing mode which is used conventionally. Thus, the reference voltage is reduced when the external voltage is low, and the reference voltage is increased when the external voltage is high, so that errors of fault detection cannot be affected due to the fact that the sampling voltage changes along with the external voltage.
2, power supply: the working power supply is provided by the step-down after the full-wave rectification of the external power supply, namely, the working power supply is directly supplied by using the external power supply of the external load connected in series, and an independent power supply is not needed. The external nonpolar connecting function is achieved, and engineering construction is facilitated.
Claims (5)
1. The utility model provides a short circuit fault detection circuit of low internal resistance load, its characterized in that includes external circuit, external power supply is connected to external circuit one end, and the other end is connected step-down circuit, external circuit includes external load and contact switch, step-down circuit connects the first input of floating comparison reference circuit, switch circuit and comparator, floating comparison reference circuit connects the second input of comparator, switch circuit passes through sampling circuit and connects the third input of comparator, switch circuit still connects isolation pulse trigger circuit, the output of comparator passes through fault signal output circuit and connects outer main circuit.
2. The short-circuit fault detection circuit with low internal resistance load according to claim 1, wherein the voltage reduction circuit comprises a rectifier bridge D3, a diode D1 and a diode D2, the rectifier bridge D3 is connected with an external circuit and a cathode of the diode D2, an anode of the diode D2 is connected with an anode of the diode D1, and a cathode of the diode D1 is connected with the floating comparison reference circuit.
3. A short circuit fault detection circuit for a low internal resistance load according to claim 1, wherein said switching circuit comprises a transistor T1.
4. The short-circuit fault detection circuit with low internal resistance load according to claim 1, wherein the isolated pulse triggering circuit comprises an optocoupler U3 and a resistor R7, and the resistor R7 is connected with an input end of the optocoupler U3.
5. A short-circuit fault detection circuit for a low internal resistance load according to claim 1, wherein said fault signal output circuit comprises an optocoupler U1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610758520.8A CN106353632B (en) | 2016-08-30 | 2016-08-30 | Short-circuit fault detection circuit with low internal resistance load |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610758520.8A CN106353632B (en) | 2016-08-30 | 2016-08-30 | Short-circuit fault detection circuit with low internal resistance load |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106353632A CN106353632A (en) | 2017-01-25 |
| CN106353632B true CN106353632B (en) | 2023-08-18 |
Family
ID=57857687
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610758520.8A Active CN106353632B (en) | 2016-08-30 | 2016-08-30 | Short-circuit fault detection circuit with low internal resistance load |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106353632B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1965463A (en) * | 2004-07-14 | 2007-05-16 | 罗姆股份有限公司 | Power source device |
| CN105372549A (en) * | 2015-11-13 | 2016-03-02 | 安徽江淮汽车股份有限公司 | High-voltage load short circuit detection system and method |
| CN105576599A (en) * | 2016-03-15 | 2016-05-11 | 西安科技大学 | Overcurrent or short-circuit fault signal isolation detection circuit and design method thereof |
| CN206114814U (en) * | 2016-08-30 | 2017-04-19 | 无锡蓝天电子股份有限公司 | Short -circuit fault detection circuitry of low internal resistance load |
-
2016
- 2016-08-30 CN CN201610758520.8A patent/CN106353632B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1965463A (en) * | 2004-07-14 | 2007-05-16 | 罗姆股份有限公司 | Power source device |
| CN105372549A (en) * | 2015-11-13 | 2016-03-02 | 安徽江淮汽车股份有限公司 | High-voltage load short circuit detection system and method |
| CN105576599A (en) * | 2016-03-15 | 2016-05-11 | 西安科技大学 | Overcurrent or short-circuit fault signal isolation detection circuit and design method thereof |
| CN206114814U (en) * | 2016-08-30 | 2017-04-19 | 无锡蓝天电子股份有限公司 | Short -circuit fault detection circuitry of low internal resistance load |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106353632A (en) | 2017-01-25 |
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