CN207677425U - Overcurrent, short-circuit protection - Google Patents
Overcurrent, short-circuit protection Download PDFInfo
- Publication number
- CN207677425U CN207677425U CN201721895488.4U CN201721895488U CN207677425U CN 207677425 U CN207677425 U CN 207677425U CN 201721895488 U CN201721895488 U CN 201721895488U CN 207677425 U CN207677425 U CN 207677425U
- Authority
- CN
- China
- Prior art keywords
- output end
- limit comparator
- voltage limit
- short
- power supply
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Abstract
The utility model is related to a kind of overcurrents,Short-circuit protection,Belong to protective device field,The utility model uses two groups of comparators, that is, upper voltage limit comparator,The comparison that lower voltage limit comparator carries out input signal judges,Because in actual conditions,The workbench electrical equipment used of imparting knowledge to students and corresponding form of power are varied,It is not limited only to exchange,Direct current,Therefore,The safe range of electric current has been set separately by two groups of comparators for the utility model,When student's operation error causes electrical equipment overcurrent occur,When the current anomalies situation such as short circuit,No matter electric current changes in what manner in safe range,After as long as abnormal current is more than or falls the safe range that and set by comparator,Subsequent switch control unit action cut-out electronic switch,Disconnect the closed circuit that electrical equipment is shown in equipment power supply,To realize the protection of electrical equipment.
Description
Technical field
The utility model belongs to protective device field, and in particular to a kind of overcurrent, short-circuit protection.
Background technology
The protective device of electric current is a kind of safety device indispensable in electrical equipment, effectively electrical equipment can be avoided to damage
It ruins, ensures personnel safety, and the various teaching equipments for being directed to school's design are even more so, because student is also in study rank
Section, still belongs to the stage more strange to electrical principle and electrical equipment, so, they are when carrying out experimental implementation, often
There is fault conditions, the experimental facilities such as equipment overcurrent, the line short of teaching equipment and will appear the excessive danger of electric current, not in time
Processing will cause great security risk even cause serious teaching accident, therefore, it is this must for experimental teaching equipment
Electric current must can be caused excessive in student's operation error, caused there are in time equipment power supply is disconnected when accident risk, to ensure
The safety of student and experimental facilities.
Utility model content
The utility model provides overcurrent, short-circuit protection, leads to solve above-mentioned problems of the prior art
Upper voltage limit comparator, the lower voltage limit comparator restriction safe voltage section of setting are crossed, whether direct current, exchange or other shapes
The fluctuating current of formula, after being converted to voltage signal by current sensor, as long as the sensor output voltage corresponding to the electric current
Signal is more than or falls and security interval, and switch control unit will be protected in time, cut off the power supply of electrical equipment, ensures
The safety of student and electrical equipment and equipment power supply.
The utility model use specific technical solution be：
Overcurrent, short-circuit protection, including current sensor, comparing unit, switch control unit, section breaker, direct current
Power supply, the comparing unit, switch control unit, section breaker are electrically connected with DC power supply respectively, the current sense
The output end of device is connect with comparing unit, and the output end of comparing unit drives section breaker, electric current to pass by switch control unit
Sensor, section breaker are connected on respectively in the closed circuit that electrical equipment is constituted with equipment power supply, the comparing unit packet
Upper voltage limit comparator, lower voltage limit comparator, reference voltage-regulating circuit are included, the reference voltage-regulating circuit includes string
The first divider resistance R1, the second divider resistance R2, the third divider resistance R3 being associated between DC power supply positive and negative electrode,
Upper voltage limit comparator：Positive terminal is electrically connected with the anode of DC power supply, and noninverting input is connected to the first partial pressure
Between resistance R1, the second divider resistance R2, reverse input end is connect with current sensor output；
Lower voltage limit comparator：Negative pole end is grounded, and reverse input end is connected to the second divider resistance R2, third divider resistance
Between R3, noninverting input is connect with current sensor output；
The output end of upper voltage limit comparator connects to form the output of comparing unit with the output end of lower voltage limit comparator
End, the output end of comparing unit are electrically connected with electronic switch.
The electronic switch includes that silicon-controlled, described section breaker is relay, and the make break contact of relay is connected
In the circuit that electrical equipment and equipment power supply are constituted, the switch control unit further includes driving triode,
Drive triode：DC power anode, collector series relay are connected with after the 4th divider resistance of base series
Control coil after with DC power supply anode connect, emitter be grounded；
It is silicon-controlled：Anode is electrically connected with the base stage of driving triode, minus earth, upper voltage limit comparator, lower voltage limit
It connects after the output end series connection of comparator and is electrically connected with control pole.
The electronic switch is also associated with delay switch module, and the delay switch module is RC delay circuits, packet
The delay capacitor C1 and discharge resistance R4 in parallel with delay capacitor C1 is included, the silicon-controlled control pole is in series with two poles of delay
The conducting direction of pipe, the delay diode is directed toward silicon-controlled control extreme direction, the negative pole end series connection of the delay diode
It is grounded after delay capacitor C1.
The electronic switch further include with silicon-controlled shorting stub in parallel, be in series with reset in the shorting stub and open
It closes.
It is electrically connected with alarm unit after the collector series diode of the driving triode, the diode is led
Alarm unit is directed toward in logical direction, and the alarm unit is connected with multigroup overcurrent, short-circuit protection.
The utility model has the beneficial effects that：
The utility model carries out input signal using two groups of comparators, that is, upper voltage limit comparator, lower voltage limit comparator
Comparison judge, because in actual conditions, impart knowledge to students the workbench electrical equipment used and corresponding form of power it is varied, not only limit
In alternating current and direct current, therefore, the safe range of electric current has been set separately by two groups of comparators for the utility model, when student operates
Error is when causing electrical equipment the current anomalies situation such as overcurrent, short circuit occur, and though electric current in safe range in what manner
Variation, as long as after abnormal current is more than or falls the safe range that and set by comparator, subsequent switch control unit acts
Electronic switch is cut off, the closed circuit that electrical equipment is shown in equipment power supply is disconnected, to realize the protection of electrical equipment.
Description of the drawings
Fig. 1 is the principles of the present invention figure；
In attached drawing, 1, current sensor, 2, comparing unit, 3, switch control unit, 4, section breaker, 5, electrical equipment,
6, equipment power supply, 201, upper voltage limit comparator, 202, lower voltage limit comparator, 301, electronic switch, 302, driving triode,
303, delay switch module, 7, alarm unit.
Specific implementation mode
Below in conjunction with the accompanying drawings and specific embodiment the utility model is described in further detail：
Specific embodiment is as shown in Figure 1, the utility model is a kind of overcurrent, short-circuit protection, including current sensor
1, comparing unit 2, switch control unit 3, section breaker 4, DC power supply, VCC in DC power supply, that is, Fig. 1, the comparison are single
Member 2, switch control unit 3, section breaker 4 be electrically connecteds with DC power supply respectively, the output end of the current sensor 1 and than
It is connected compared with unit 2, the output end of comparing unit 2 drives section breaker 4, current sensor 1, disjunction by switch control unit 3
Switch 4 is connected on respectively in the closed circuit that electrical equipment 5 is constituted with equipment power supply 6, and the comparing unit 2 includes voltage
Upper limit comparator 201, lower voltage limit comparator 202, reference voltage-regulating circuit, the reference voltage-regulating circuit include string
The first divider resistance R1, the second divider resistance R2, the third divider resistance R3 being associated between DC power supply positive and negative electrode,
Upper voltage limit comparator 201：Positive terminal is electrically connected with the anode of DC power supply, and noninverting input is connected to first point
Between piezoresistance R1, the second divider resistance R2, reverse input end is connect with 1 output end of current sensor, and negative pole end is hanging；
Lower voltage limit comparator 202：Negative pole end is grounded, and reverse input end is connected to the second divider resistance R2, third partial pressure
Between resistance R3, noninverting input is connect with 1 output end of current sensor, and positive terminal is hanging；
The output end of upper voltage limit comparator 201 connects to form comparing unit 2 with the output end of lower voltage limit comparator 202
Output end, the output end of comparing unit 2 is electrically connected with electronic switch 301.
The operation principle of the utility model is, by the first divider resistance R1, the second divider resistance R2, third divider resistance
R3 connects, and is adjusted by the resistance value ratio of three resistance of adjusting or using adjustable resistance so that the partial pressure between resistance
Variation, so that the reference voltage that upper voltage limit comparator 201, lower voltage limit comparator 202 are got is adjustable, operating personnel
Or teacher can draw a circle to approve suitable interval range according to actual needs, the current sensor of setting uses Hall sensor,
Output signal is voltage signal, upper voltage limit comparator 201,202 real time contrast's current sensor 1 of lower voltage limit comparator it is defeated
The magnitude relationship for going out signal and the reference voltage of setting, when the output signal of current sensor 1 exceeds or drops into reference to electricity
When pressure is outer, upper voltage limit comparator 201,202 output end of lower voltage limit comparator send out electric signal and start electronic switch 301.
The electronic switch 301 includes that silicon-controlled, described section breaker 4 is relay, the make break contact of relay
It is connected in the circuit that electrical equipment 5 is constituted with equipment power supply 6, the switch control unit 3 further includes driving triode
302,
Drive triode 302：It is connected with DC power anode after the 4th divider resistance of base series, by the 4th partial pressure electricity
Resistance avoids base stage drop-down not in place, causes driving triode 302 that cannot correctly end, the control coil of collector series relay
It is connect afterwards with the anode of DC power supply, emitter ground connection；The utility model is in normally, base stage high level, driving
Triode 302 is connected, and the coil of relay is powered on, and make break contact is closed so that electrical equipment 5 can be with equipment power supply 6
It forms closed circuit and ensures normal use.
It is silicon-controlled：Anode is electrically connected with the base stage of driving triode 302, minus earth, upper voltage limit comparator 201, electricity
It connects after the output end series connection of pressure limit comparator 202 and is electrically connected with control pole.
After silicon-controlled control pole powers on triggering by comparator, silicon-controlled anode is connected with cathode, the driving
The base stage of triode 302 is short-circuited, and the base voltage to cause driving triode 302 is zero, and driving triode 302 is cut
Only, relay can not continue to power, to play the role of disconnecting the power supply of electrical equipment.
Further, after protection equipment accesses capacitive load or inductive load in order to prevent, in the big electricity for starting moment
Malfunction caused by stream occurs, and the electronic switch 301 is also associated with delay switch module 303, the delay switch module
303 are connected between the output end of comparing unit 2 and silicon-controlled control pole.The delay switch module 303 be delay after
Electrical appliance module or RC delay circuit modules, effect be upon power-up between shorter than delay switch 303 setting time of module when, delay
Switch module 303 is not turned on, and subsequent conditioning circuit not will receive maloperation signal；
RC delay circuit modules include the delay capacitor C1 and discharge resistance R4 in parallel with delay capacitor C1, and described is controllable
The control pole of silicon is in series with delay diode, and the conducting direction of the delay diode is directed toward silicon-controlled control extreme direction, described
Delay diode negative pole end series connection delay capacitor C1 after be grounded, and comparator reversion output is low level, can will be relatively more single
The low level of comparator output is switched into high level after first output end concatenation PNP type triode.It is generated more than peace when connecting moment
After the electric current of gamut, comparing unit sends out trigger signal, the high level that delay capacitor C1 is provided by PNP type triode at this time
It charges, since capacitive load or inductive load startup instantaneous large-current duration are short, delay capacitor C1 and delay two
Due to capacitor charging time deficiency, the voltage of conducting delay diode is not achieved in the voltage of delay capacitor C1 for the connecting pin of pole pipe,
Therefore, it electronic switch 301 and is failure to actuate, when there are the accidents situations such as short circuit, overcurrent, generation duration high current, is delayed at this time
Capacitance C1 and the voltage of the connecting pin of delay diode, which continue to increase to delay capacitor C1, to be full of, at this point, delay diode current flow,
Electronic switch 301 is triggered to act；The discharge resistance R4 of setting is delay capacitor C1 electric discharges in time, avoids capacitive or inductive load
Repeatedly start, leads to delay capacitor C1 accumulation chargings, the delay diode triggered that misleads electronic switch 301；
Or controlled using with the single-chip minimum system module of clocking capability, when detecting comparator output
After low level, delay predetermined time is acted by microcontroller triggering following again, to realize accidentally touch protection, ensure that capacitive or
The normal use of inductive load.
Further, can not voluntarily be disconnected after switch due to silicon-controlled, the electronic switch 301 further include with controllably
The shorting stub of silicon parallel connection is in series with reset switch in the shorting stub.After troubleshooting, staff or substitute teacher
Pressing reset switch will disconnect after silicon-controlled access short circuit, to realize the reset of equipment, drive 302 base of triode at this time
Pole regains high level, and relay powers on, and make break contact is closed.
Further, the effect of guard mode, the driving triode are come into order to play prompt user equipment
It is electrically connected with alarm unit 7 after 302 collector series diode, since scene of in practical operation, especially imparting knowledge to students needs to use
To a variety of teaching equipments and there are multiple students while operating, the alarm unit 7 is connected with multigroup overcurrent, short-circuit protection dress
It sets, in order to avoid multigroup and overcurrent even, short-circuit protection interfere with each other two poles added conducting direction and be directed toward alarm unit 7
Pipe, when a certain group of overcurrent, short-circuit protection are protected, adjacent overcurrent, short-circuit protection will not be interfered, to
Realize multiple overcurrents, short-circuit protection shares the effect of an alarm unit 7, improves intensive degree, effective reduction
Cost.
When the driving cut-off of triode 302, the collector connecting pin dead electricity of alarm unit 7 and driving triode 302, to touch
The cut-offing alarming circuit of alarm unit 7 is sent out, starts the warning devices such as buzzer, warning light and alarms.
Claims (6)
1. overcurrent, short-circuit protection, including current sensor (1), comparing unit (2), switch control unit (3), disjunction are opened
(4), DC power supply are closed, the comparing unit (2), switch control unit (3), section breaker (4) are electric with DC power supply respectively
Connection, the output end of the current sensor (1) are connect with comparing unit (2), and the output end of comparing unit (2) is by switch
Control unit (3) drives section breaker (4), and current sensor (1), section breaker (4) are connected on electrical equipment (5) and set respectively
In the closed circuit that stand-by power source (6) is constituted, it is characterised in that：The comparing unit (2) includes input terminal and current sense
Upper voltage limit comparator (201), the lower voltage limit comparator (202) of device (1) output end connection, the upper voltage limit comparator
(201), lower voltage limit comparator (202) is also associated with reference voltage-regulating circuit.
2. overcurrent according to claim 1, short-circuit protection, it is characterised in that：The reference voltage-regulating circuit
Including the first divider resistance R1, the second divider resistance R2, the third divider resistance R3 being connected between DC power supply positive and negative electrode；
The upper voltage limit comparator (201)：Positive terminal is electrically connected with the anode of DC power supply, and noninverting input is connected to first
Between divider resistance R1, the second divider resistance R2, reverse input end is connect with current sensor (1) output end；
The lower voltage limit comparator (202)：Negative pole end is grounded, and reverse input end is connected to the second divider resistance R2, third point
Between piezoresistance R3, noninverting input is connect with current sensor (1) output end；
The output end of upper voltage limit comparator (201) connects to form comparing unit with the output end of lower voltage limit comparator (202)
(2) output end, the output end of comparing unit (2) are electrically connected with the electronic switch (301) of switch control unit (3).
3. overcurrent according to claim 2, short-circuit protection, it is characterised in that：The electronic switch (301) includes
Silicon-controlled, the section breaker (4) is relay, and the make break contact of relay is connected on electrical equipment (5) and equipment power supply
(6) in the circuit constituted, the switch control unit (3) further includes driving triode (302),
Drive triode (302)：DC power anode, collector series relay are connected with after the 4th divider resistance of base series
Control coil after with DC power supply anode connect, emitter be grounded；
It is silicon-controlled：Anode is electrically connected with the base stage of driving triode (302), minus earth, upper voltage limit comparator (201), electricity
It connects after the output end series connection of pressure limit comparator (202) and is electrically connected with control pole.
4. overcurrent according to claim 3, short-circuit protection, it is characterised in that：The electronic switch (301) also connects
Be connected to delay switch module (303), the delay switch module (303) be connected on the output end of comparing unit (2) with it is controllable
Between the control pole of silicon.
5. overcurrent according to claim 3, short-circuit protection, it is characterised in that：The electronic switch (301) also wraps
Include with silicon-controlled shorting stub in parallel, be in series with reset switch in the shorting stub.
6. overcurrent according to claim 3, short-circuit protection, it is characterised in that：The driving triode (302)
Alarm unit (7) is electrically connected with after collector series diode, the conducting direction of the diode is directed toward alarm unit (7),
The alarm unit (7) is connected with multigroup overcurrent, short-circuit protection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721895488.4U CN207677425U (en) | 2017-12-29 | 2017-12-29 | Overcurrent, short-circuit protection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721895488.4U CN207677425U (en) | 2017-12-29 | 2017-12-29 | Overcurrent, short-circuit protection |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207677425U true CN207677425U (en) | 2018-07-31 |
Family
ID=62971763
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201721895488.4U Active CN207677425U (en) | 2017-12-29 | 2017-12-29 | Overcurrent, short-circuit protection |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN207677425U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109245502A (en) * | 2018-09-12 | 2019-01-18 | 中车大连机车车辆有限公司 | A kind of DC loop overvoltage protective system and rail vehicle |
| CN110190582A (en) * | 2019-05-28 | 2019-08-30 | 西南电子技术研究所（中国电子科技集团公司第十研究所） | Total state monitoring band power-off protection warning circuit |
| CN111023395A (en) * | 2019-12-11 | 2020-04-17 | 广州视源电子科技股份有限公司 | Monitoring circuit and air conditioner |
-
2017
- 2017-12-29 CN CN201721895488.4U patent/CN207677425U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109245502A (en) * | 2018-09-12 | 2019-01-18 | 中车大连机车车辆有限公司 | A kind of DC loop overvoltage protective system and rail vehicle |
| CN109245502B (en) * | 2018-09-12 | 2020-03-31 | 中车大连机车车辆有限公司 | Direct current circuit overvoltage protection system and rail vehicle |
| CN110190582A (en) * | 2019-05-28 | 2019-08-30 | 西南电子技术研究所（中国电子科技集团公司第十研究所） | Total state monitoring band power-off protection warning circuit |
| CN111023395A (en) * | 2019-12-11 | 2020-04-17 | 广州视源电子科技股份有限公司 | Monitoring circuit and air conditioner |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN203787935U (en) | Over-current protection circuit based on high side current detection | |
| US9219360B2 (en) | Safe quick disconnect leakage protector | |
| CN207677425U (en) | Overcurrent, short-circuit protection | |
| CN103872658B (en) | Multifunction self-resetting formula is crossed, under-voltage protector | |
| CN103066559B (en) | Power-off protector | |
| CN101316038A (en) | Control circuit of multifunctional protection socket | |
| CN101976815B (en) | Loaded multifunctional protection circuit | |
| CN101872956B (en) | Leakage current detection protection circuit | |
| CN101872957B (en) | Leakage current detection protection circuit | |
| CN101388540A (en) | Leakage protection circuit having life end detection and display functions | |
| CN201113383Y (en) | Earth leakage protective circuit possessing end-to-life detection and display function | |
| CN201422011Y (en) | Leakage-detecting protective circuit | |
| US9312678B2 (en) | Surge protection device | |
| CN204858515U (en) | Overcurrent protection circuit | |
| CN203243019U (en) | Power-off protector | |
| CN104953537A (en) | Overload protection switching device | |
| CN115693593A (en) | Overvoltage protection device of vehicle power supply, vehicle and overvoltage protection method of vehicle power supply | |
| CN108418173A (en) | A kind of arc-fault circuit interrupter | |
| CN101944716B (en) | Electricity leakage detection protective circuit | |
| CN201260066Y (en) | Control circuit for multifunctional protection socket | |
| CN203276459U (en) | Electrical fire monitoring detector having overvoltage under-voltage detecting and protective functions | |
| CN201490709U (en) | Anti-dead halt lightning arrester | |
| CN102495364B (en) | Detection device of three-phase fuse | |
| CN204792666U (en) | Fuse -element malfunction alerting ware | |
| CN201422008Y (en) | Electric leakage inspecting protection circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |