CN204886686U - Constant voltage power supply with current -limiting overload protection - Google Patents
Constant voltage power supply with current -limiting overload protection Download PDFInfo
- Publication number
- CN204886686U CN204886686U CN201520683655.3U CN201520683655U CN204886686U CN 204886686 U CN204886686 U CN 204886686U CN 201520683655 U CN201520683655 U CN 201520683655U CN 204886686 U CN204886686 U CN 204886686U
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- type triode
- pnp type
- power supply
- voltage power
- terminal
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Abstract
The utility model discloses a current -limiting overload protection constant voltage power supply has: three terminal regulator IC input termination PNP type triode T1 collecting electrode, not ground connection termination to ground, output termination stabilized power supply output end inserts electric capacity C2 between this output terminal and the ground, PNP type triode T1 projecting pole connects the input terminal to constant voltage power supply, and PNP type triode T1 base is connected with PNP type triode T2 projecting pole through resistance R3, and access electric capacity C1 does not insert resistance R1 between PNP type triode T1 collecting electrode and the ground between PNP type triode T1 projecting pole and the collecting electrode, inserts resistance R4 between PNP type triode T1 base and the three terminal regulator IC output, PNP type triode T2 projecting pole connects the input terminal to constant voltage power supply through resistance R2, PNP type triode T2 collecting electrode and constant voltage power supply output terminal connection, and PNP type triode T2 base is connected with PNP type triode T1 collecting electrode. The utility model discloses current -limiting overload protection circuit has been installed additional for output voltage reduces, and the electric current reduces, from this the safety of protection circuit.
Description
Technical field
The utility model relates to voltage-stabilized power supply circuit, particularly a kind of stabilized voltage power supply with foldback current limiting.
Background technology
Three terminal regulator can expand stream with transistor; the design of its foldback current limiting must be paid attention to; because the power consumption when short circuit is king-sized; otherwise bring adverse effect by the safety of electronic product, be necessary thus to this be that the stabilized voltage power supply of core gives optimal design with three terminal regulator.
Utility model content
In view of this, the purpose of this utility model is a kind of stabilized voltage power supply with foldback current limiting, to protect the safety of electronic product.
For solving the problems of the technologies described above, the utility model provides a kind of stabilized voltage power supply with foldback current limiting, comprise the peripheral circuit that three terminal regulator IC and PNP type triode T1, PNP type triode T2 are formed, wherein: the collector electrode of the input termination PNP type triode T1 of three terminal regulator IC, the earth terminal of three terminal regulator IC is connected to ground, the lead-out terminal of the output termination stabilized voltage power supply of three terminal regulator IC, accesses electric capacity C2 between the lead-out terminal of this stabilized voltage power supply and ground; The emitter of PNP type triode T1 is connected to the input terminal of stabilized voltage power supply, the base stage of PNP type triode T1 is connected with the emitter of PNP type triode T2 through resistance R3, electric capacity C1 is accessed between the collector electrode of PNP type triode T1 and ground, access resistance R1 between the emitter of PNP type triode T1 and collector electrode, between the base stage of PNP type triode T1 and the output of three terminal regulator IC, access resistance R4; The emitter of PNP type triode T2 is connected to the input terminal of stabilized voltage power supply through resistance R2, the collector electrode of PNP type triode T2 is connected with the lead-out terminal of stabilized voltage power supply, and the base stage of PNP type triode T2 is connected with the collector electrode of PNP type triode T1.
More preferably, three terminal regulator IC selects 7805.
Compared with prior art; the utility model devises the stabilized voltage power supply that a kind of circuit configuration simply has foldback current limiting, and it has installed foldback current limiting circuit additional, makes to obtain output voltage during output loading and reduces; electric current is greatly reduced, thus the safety of protective circuit.
Accompanying drawing explanation
Fig. 1 is the circuit diagram that the utility model has the stabilized voltage power supply of foldback current limiting.
Embodiment
In order to make those skilled in the art understand the technical solution of the utility model better, below in conjunction with the drawings and specific embodiments, the utility model is described in further detail.
See Fig. 1, there is for the utility model the circuit diagram of the stabilized voltage power supply of foldback current limiting.This stabilized voltage power supply (hereinafter referred to as stabilized voltage power supply) with foldback current limiting comprises three terminal regulator IC (type selecting is 7805) and comprises the peripheral circuit of PNP type triode T1, PNP type triode T2 formation, and wherein three terminal regulator IC is the core of circuit.Concrete circuit structure is: the collector electrode of the input termination PNP type triode T1 of three terminal regulator IC, the earth terminal of three terminal regulator IC is connected to ground, the lead-out terminal Vo of the output termination stabilized voltage power supply of three terminal regulator IC, accesses electric capacity C2 between the lead-out terminal Vo of this stabilized voltage power supply and ground; The emitter of PNP type triode T1 is connected to the input terminal Vin of stabilized voltage power supply, the base stage of PNP type triode T1 is connected with the emitter of PNP type triode T2 through resistance R3, electric capacity C1 is accessed between the collector electrode of PNP type triode T1 and ground, access resistance R1 between the emitter of PNP type triode T1 and collector electrode, between the base stage of PNP type triode T1 and the output of three terminal regulator IC, access resistance R4; The emitter of PNP type triode T2 is connected to the input terminal Vin of stabilized voltage power supply through resistance R2, the collector electrode of PNP type triode T2 is connected with the lead-out terminal Vo of stabilized voltage power supply, and the base stage of PNP type triode T2 is connected with the collector electrode of PNP type triode T1.
The element of this stabilized voltage power supply is less; wherein: PNP type triode T1 plays metering function; voltage when protective circuit is in work equals the voltage sum of resistance R2+R3; resistance R3 and R4 forms voltage divider to PNP type triode T2; the power consumption of PNP type triode T2 is directly proportional to collector emitter voltage, is therefore used to Limited Current.Like this, the property of this stabilized voltage power supply is a function of input voltage level.Once the voltage on resistance R2+R3 exceedes the conducting voltage of PNP type triode T1, PNP type triode T1 is conducting immediately, and the base current of PNP type triode T2 is kept to zero effectively.This pressurizer except self pressure stabilization function, also has heat protective effect more or less, and limits output current well before any burn observations.
Although the utility model with preferred embodiment openly as above; but it is not for limiting the utility model; any those skilled in the art are not departing from spirit and scope of the present utility model; can make possible variation and amendment, the scope that therefore protection range of the present utility model should define with the utility model claim is as the criterion.
Claims (2)
1. one kind has the stabilized voltage power supply of foldback current limiting, it is characterized in that, comprise the peripheral circuit that three terminal regulator IC and PNP type triode T1, PNP type triode T2 are formed, wherein: the collector electrode of the input termination PNP type triode T1 of three terminal regulator IC, the earth terminal of three terminal regulator IC is connected to ground, the lead-out terminal of the output termination stabilized voltage power supply of three terminal regulator IC, accesses electric capacity C2 between the lead-out terminal of this stabilized voltage power supply and ground; The emitter of PNP type triode T1 is connected to the input terminal of stabilized voltage power supply, the base stage of PNP type triode T1 is connected with the emitter of PNP type triode T2 through resistance R3, electric capacity C1 is accessed between the collector electrode of PNP type triode T1 and ground, access resistance R1 between the emitter of PNP type triode T1 and collector electrode, between the base stage of PNP type triode T1 and the output of three terminal regulator IC, access resistance R4; The emitter of PNP type triode T2 is connected to the input terminal of stabilized voltage power supply through resistance R2, the collector electrode of PNP type triode T2 is connected with the lead-out terminal of stabilized voltage power supply, and the base stage of PNP type triode T2 is connected with the collector electrode of PNP type triode T1.
2. have the stabilized voltage power supply of foldback current limiting as claimed in claim 1, it is characterized in that, three terminal regulator IC selects 7805.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520683655.3U CN204886686U (en) | 2015-09-06 | 2015-09-06 | Constant voltage power supply with current -limiting overload protection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520683655.3U CN204886686U (en) | 2015-09-06 | 2015-09-06 | Constant voltage power supply with current -limiting overload protection |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204886686U true CN204886686U (en) | 2015-12-16 |
Family
ID=54831006
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201520683655.3U Expired - Fee Related CN204886686U (en) | 2015-09-06 | 2015-09-06 | Constant voltage power supply with current -limiting overload protection |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204886686U (en) |
-
2015
- 2015-09-06 CN CN201520683655.3U patent/CN204886686U/en not_active Expired - Fee Related
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20151216 Termination date: 20160906 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |