CN201213221Y - Current limiting protector for household electrical appliance - Google Patents
Current limiting protector for household electrical appliance Download PDFInfo
- Publication number
- CN201213221Y CN201213221Y CNU2008201090683U CN200820109068U CN201213221Y CN 201213221 Y CN201213221 Y CN 201213221Y CN U2008201090683 U CNU2008201090683 U CN U2008201090683U CN 200820109068 U CN200820109068 U CN 200820109068U CN 201213221 Y CN201213221 Y CN 201213221Y
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- circuit
- capacitor
- household electrical
- power supply
- monostable
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Abstract
The utility model relates to a household electrical appliance current limiting protector used for household electrical appliances and preventing a household circuit from overloading. The household electrical appliance current limiting protector comprises an overcurrent detecting circuit, a DC power supply circuit, a monostable circuit, a time delay circuit and a switch circuit, wherein the DC power supply circuit consists of a capacitor C1, rectifier bridges D1-D4, a capacitor C2 and a three-terminal regulator IC1; the monostable circuit consists of a three-terminal regulator IC2; the time delay circuit consists of a diode D7, a capacitor C 5, a resistor R3 and a diode D8; the switch circuit consists of a triode V; and the overcurrent detecting circuit consists of a current transformator T, a resistor RP, a capacitor C4 and a diode D5. The utility model is simple in circuit, easy to manufacture, low in cost, and suitable for various household electrical appliances.
Description
Technical field
The utility model is a kind of excessive limiting protector of electric current in the circuit that prevents, particularly a kind of household electrical appliances limiting protector that is used for the family expenses the avoided circuit overload of household electrical appliances.
Background technology
The bearing capacity of family expenses circuit is limited, if long-term excess load is used, can make the electric wire premature aging, even causes and cause serious accident by fire.For fear of the overload of family expenses circuit, just a kind of current limiting measures must be arranged.Current foldback circuit is an indispensable part in the household appliances, roughly can be divided into shutoff mode and current-limiting mode according to its control method.Therefore current-limiting mode obtains using more widely because it has the electric current droop characteristic, and Switching Power Supply can be resumed work automatically after the trouble shooting.Current-limiting protection circuit at first will have a current sampling link, and at present, general way is small resistor of series connection or obtains current signal with Hall element.When sampling current was smaller, these two kinds of sampling methods all were desirable.But when sampling current was bigger, resistance sampling had bigger loss, had reduced the efficient of converter, and Hall element its volume ratio of taking a sample is bigger, and cost an arm and a leg, and also was a problem to the cost of whole power supply.
Summary of the invention
The purpose of this utility model is to reach the high defective of expense greatly in order to overcome existing current-limiting mode loss; invent a kind of household electrical appliances limiting protector that adopts electronic circuit; surpass to set rated current in the time of 3-4 seconds when electric current, this circuit can cut off the power supply automatically, can prevent the voltage damage household electrical appliance that raise suddenly.
The purpose of this utility model realizes as follows: described household electrical appliances limiting protector comprises over-current detection circuit, DC power supply circuit, monostable circuit, delay circuit and switching circuit; DC power supply circuit is made of capacitor C 1, rectifier bridge D1-D4, capacitor C 2 and three terminal regulator IC1, and it provides DC power supply for monostable circuit, delay circuit and switching circuit; Monostable circuit is made of IC2, and delay circuit is made of diode D7, capacitor C 5, resistance R 3 and diode D8, and switching circuit is made of triode V; 8,4 jiaos of DC power supply circuit and monostable circuit are connected, and 5 pin of monostable circuit are connected with delay circuit with LED by resistance R 1 by capacitor C 3 and 3 pin; Delay circuit is connected with switching circuit by resistance R 2; Over-current detection circuit is made of current transformer T, resistance R P, capacitor C 4 and diode D5, and over-current detection circuit is connected with 6 pin with 2 pin of monostable circuit by diode D6; A current transformer T just end of the utmost point is connected with alternating current by bidirectional triode thyristor SCR1, the current transformer T just other end of the utmost point is connected with alternating current with bidirectional triode thyristor SCR2 by socket K, and the trigger electrode of bidirectional triode thyristor SCR1 and bidirectional triode thyristor SCR2 is connected with switching circuit.
The model of described three terminal regulator IC1 is 7815.
The model of described monostable circuit IC2 is NE555.
Good effect of the present utility model is as follows: the utility model utilizes the variation of electric current in the current transformer detection line, become the change transitions of electric current in the circuit variation of voltage to send IC2 integrated circuit, control the break-make of triode by the output of IC2 integrated circuit, thereby the break-make of control bidirectional triode thyristor reaches the purpose that limits electric current; The utility model circuit is simple, makes easily, and with low cost, it is applicable to various household electrical appliance.
Description of drawings
Fig. 1 is the utility model circuit theory diagrams
Fig. 2 is the utility model circuit block diagram
Embodiment
Shown in Figure 2 as Fig. 1, described household electrical appliances limiting protector comprises over-current detection circuit, DC power supply circuit, monostable circuit, delay circuit and switching circuit; DC power supply circuit is made of capacitor C 1, rectifier bridge D1-D4, capacitor C 2 and three terminal regulator IC1, and it provides DC power supply for monostable circuit, delay circuit and switching circuit; Monostable circuit is made of IC2, and delay circuit is made of diode D7, capacitor C 5, resistance R 3 and diode D8, and switching circuit is made of triode V; 8,4 jiaos of DC power supply circuit and monostable circuit are connected, and 5 pin of monostable circuit are connected with delay circuit with LED by resistance R 1 by capacitor C 3 and 3 pin; Delay circuit is connected with switching circuit by resistance R 2; Over-current detection circuit is made of current transformer T, resistance R P, capacitor C 4 and diode D5, and over-current detection circuit is connected with 6 pin with 2 pin of monostable circuit by diode D6; A current transformer T just end of the utmost point is connected with alternating current by bidirectional triode thyristor SCR1, the current transformer T just other end of the utmost point is connected with alternating current with bidirectional triode thyristor SCR2 by socket K, and the trigger electrode of bidirectional triode thyristor SCR1 and bidirectional triode thyristor SCR2 is connected with switching circuit.
The model of described three terminal regulator IC1 is 7815.
The model of described monostable circuit IC2 is NE555.
Operation principle of the present utility model is as follows:
When having electric current to flow through in the primary coil of current transformer T, at secondary generation one induced voltage, primary voltage increases, and then primary current is big more, and secondary induction voltage is high more, and the voltage on the RP is big more.If this moment, voltage was lower than
The time, the 2nd pin of IC2 and the 6th pin are low level, its 3rd pin output high level, and IC2 is in stable state, triode V conducting, voltage triggered bidirectional triode thyristor SCR1, the SCR2 conducting of its emitter output, civil power is powered to household electrical appliances, household electric appliance operation.
When line current increased the rated current that surpasses setting, the 2nd pin of IC2 and the 6th pin current potential were higher than
The time, the IC2 upset, trigger is in transient state, its 3rd pin output low level.Triode V can not end through the slow discharge of R3 immediately because of capacitor C 5, and after 3-4 seconds, capacitor discharge finishes, triode V ends, the control utmost point of bidirectional triode thyristor loses trigger voltage and blocks, and the 220V power supply is cut off, and has guaranteed that household electrical appliance can not burn out because of the voltage overcurrent that rises.
Be provided with two bidirectional triode thyristors in the circuit, needn't distinguish live wire and zero line in use, the unsafe factor that brings in the time of can preventing live wire and zero line exchange under the fortuitous event.
Represent when LED is lighted that line current is normal, be overload when extinguishing.
After installing, connect electrical equipment, RP is adjusted to the minimum power place by maximum power, just tripping operation, fine setting in the other direction gets final product operate as normal more afterwards.
Claims (3)
1. household electrical appliances limiting protector, comprise DC power supply circuit, DC power supply circuit is made of capacitor C 1, rectifier bridge D1-D4, capacitor C 2 and three terminal regulator IC1, it is characterized in that: also comprise monostable circuit, delay circuit, switching circuit and over-current detection circuit, DC power supply circuit provides DC power supply for monostable circuit, delay circuit and switching circuit, monostable circuit is made of IC2, delay circuit is made of diode D7, capacitor C 5, resistance R 3 and diode D8, and switching circuit is made of triode V; 8,4 jiaos of DC power supply circuit and monostable circuit are connected, and 5 pin of monostable circuit are connected with delay circuit with LED by resistance R 1 by capacitor C 3 and 3 pin; Delay circuit is connected with switching circuit by resistance R 2; Over-current detection circuit is made of current transformer T, resistance R P, capacitor C 4 and diode D5, and over-current detection circuit is connected with 6 pin with 2 pin of monostable circuit by diode D6; A current transformer T just end of the utmost point is connected with alternating current by bidirectional triode thyristor SCR1, the current transformer T just other end of the utmost point is connected with alternating current with bidirectional triode thyristor SCR2 by socket K, and the trigger electrode of bidirectional triode thyristor SCR1 and bidirectional triode thyristor SCR2 is connected with switching circuit.
2. household electrical appliances limiting protector according to claim 1 is characterized in that: the model of described three terminal regulator IC1 is 7815.
3. household electrical appliances limiting protector according to claim 1 is characterized in that: the model of described monostable circuit IC2 is NE555.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008201090683U CN201213221Y (en) | 2008-07-07 | 2008-07-07 | Current limiting protector for household electrical appliance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008201090683U CN201213221Y (en) | 2008-07-07 | 2008-07-07 | Current limiting protector for household electrical appliance |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201213221Y true CN201213221Y (en) | 2009-03-25 |
Family
ID=40497399
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2008201090683U Expired - Fee Related CN201213221Y (en) | 2008-07-07 | 2008-07-07 | Current limiting protector for household electrical appliance |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201213221Y (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111130068A (en) * | 2019-12-23 | 2020-05-08 | 珠海格力电器股份有限公司 | Direct-current bus short-circuit fault protection circuit and method and direct-current bus system |
-
2008
- 2008-07-07 CN CNU2008201090683U patent/CN201213221Y/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111130068A (en) * | 2019-12-23 | 2020-05-08 | 珠海格力电器股份有限公司 | Direct-current bus short-circuit fault protection circuit and method and direct-current bus system |
| CN111130068B (en) * | 2019-12-23 | 2021-11-19 | 珠海格力电器股份有限公司 | Direct-current bus short-circuit fault protection circuit and method and direct-current bus system |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090325 Termination date: 20100707 |