CN202797928U - Overcurrent protection circuit - Google Patents
Overcurrent protection circuit Download PDFInfo
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- CN202797928U CN202797928U CN 201220508851 CN201220508851U CN202797928U CN 202797928 U CN202797928 U CN 202797928U CN 201220508851 CN201220508851 CN 201220508851 CN 201220508851 U CN201220508851 U CN 201220508851U CN 202797928 U CN202797928 U CN 202797928U
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- bipolar transistor
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Abstract
The utility model discloses an overcurrent protection circuit, comprising an input end (Vin) and an output end (Vout). A first resistor (R1) is in series connection between the input end (Vin) and the output end (Vout); the source of a first bipolar transistor (Q1) is connected with the input end (Vin), the base is connected with the output end (Vout) via a second resistor (R2) and is connected with the source of a second bipolar transistor (Q2) via a third resistor (R3), and the collector is grounded (GND) via a fourth resistor (R4) and an inductor (L) which are in series connections; the collector and base of the second bipolar transistor (Q2) are both connected with the output end (Vout), and the source is grounded (GND) via a fifth resistor (R5). The beneficial effects of the utility model are that the circuit structure is simple, and the employment period is reduced, so that the cost is saved and the own power consumption is low.
Description
Technical field
The utility model relates to a kind of current foldback circuit.
Background technology
In some portable electric electronic circuits, the required current constant of circuit of part.But in the reality since power supply be subject to various interference and often occur, can cause circuit than great fluctuation process, circuit is caused damage.The current-limiting circuit of prior art generally be complex structure, with high costs, oneself power consumption is also larger.
The utility model content
Goal of the invention of the present utility model is: for the problem of above-mentioned existence, provide a kind of current foldback circuit.
The technical solution adopted in the utility model is such: a kind of current foldback circuit, comprise input and output, and this circuit also comprises the first bipolar transistor, the second bipolar transistor; Serial connection one first resistance between described input and the output; The source electrode of described the first bipolar transistor is connected to input, and base stage is connected to output and is connected to the source electrode of the second bipolar transistor by the 3rd resistance by the second resistance, and collector electrode is connected to ground by the 4th resistance and the inductance of serial connection; The collector electrode of described the second bipolar transistor and base stage all are connected to output, and source electrode is by the 5th grounding through resistance.
In above-mentioned circuit, described the first bipolar transistor is the PNP bipolar transistor.
In above-mentioned circuit, described the second bipolar transistor is the NPN bipolar transistor.
In sum, owing to adopted technique scheme, the beneficial effects of the utility model are: circuit structure is simple, the phase of employing reduce therefore provide cost savings and oneself power consumption low.
Description of drawings
Fig. 1 is the circuit theory diagrams of the utility model current foldback circuit.
Embodiment
Below in conjunction with accompanying drawing, the utility model is described in detail.
In order to make the purpose of this utility model, technical scheme and advantage clearer, below in conjunction with drawings and Examples, the utility model is further elaborated.Should be appreciated that specific embodiment described herein only in order to explaining the utility model, and be not used in restriction the utility model.
As shown in Figure 1, be the circuit theory diagrams of the utility model current foldback circuit.
A kind of current foldback circuit of the present utility model comprises input Vin and output end vo ut, and this circuit also comprises the first bipolar transistor Q1, the second bipolar transistor Q2; Serial connection one first resistance R 1 between described input Vin and the output end vo ut; The source electrode of described the first bipolar transistor Q1 is connected to input Vin, base stage is connected to output end vo ut and is connected to the source electrode of the second bipolar transistor Q2 by the 3rd resistance R 3 by the second resistance R 2, and collector electrode is connected to ground GND by the 4th resistance R 4 and the inductance L of serial connection; The collector electrode of described the second bipolar transistor Q2 and base stage all are connected to output end vo ut, and source electrode is by the 5th resistance R 5 ground connection GND.
In the above-mentioned circuit of the utility model, described the first bipolar transistor Q1 is the PNP bipolar transistor.
In the above-mentioned circuit of the utility model, described the second bipolar transistor Q2 is the NPN bipolar transistor.
The above only is preferred embodiment of the present utility model; not in order to limit the utility model; all any modifications of within spirit of the present utility model and principle, doing, be equal to and replace and improvement etc., all should be included within the protection range of the present utility model.
Claims (3)
1. a current foldback circuit comprises input (Vin) and output (Vout), it is characterized in that, also comprises the first bipolar transistor (Q1), the second bipolar transistor (Q2); Serial connection one first resistance (R1) between described input (Vin) and the output (Vout); The source electrode of described the first bipolar transistor (Q1) is connected to input (Vin), base stage is connected to output (Vout) also is connected to the second bipolar transistor (Q2) by the 3rd resistance (R3) source electrode by the second resistance (R2), and collector electrode is connected to ground (GND) by the 4th resistance (R4) and the inductance (L) of serial connection; The collector electrode of described the second bipolar transistor (Q2) and base stage all are connected to output (Vout), and source electrode is by the 5th resistance (R5) ground connection (GND).
2. current foldback circuit according to claim 1 is characterized in that, described the first bipolar transistor (Q1) is the PNP bipolar transistor.
3. current foldback circuit according to claim 1 and 2 is characterized in that, described the second bipolar transistor (Q2) is the NPN bipolar transistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220508851 CN202797928U (en) | 2012-10-06 | 2012-10-06 | Overcurrent protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220508851 CN202797928U (en) | 2012-10-06 | 2012-10-06 | Overcurrent protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202797928U true CN202797928U (en) | 2013-03-13 |
Family
ID=47825104
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201220508851 Expired - Fee Related CN202797928U (en) | 2012-10-06 | 2012-10-06 | Overcurrent protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202797928U (en) |
-
2012
- 2012-10-06 CN CN 201220508851 patent/CN202797928U/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 | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130313 Termination date: 20131006 |