CN204720966U - DC-DC power source output overcurrent short-circuit protection circuit - Google Patents
DC-DC power source output overcurrent short-circuit protection circuit Download PDFInfo
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- CN204720966U CN204720966U CN201520463173.7U CN201520463173U CN204720966U CN 204720966 U CN204720966 U CN 204720966U CN 201520463173 U CN201520463173 U CN 201520463173U CN 204720966 U CN204720966 U CN 204720966U
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- resistance
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- stable pressure
- power source
- electric capacity
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Abstract
A kind of DC-DC power source output overcurrent short-circuit protection circuit, comprise: sample circuit, comprise the first resistance, the second resistance and diode, the first resistance is all connected with DC-DC output feedack end with one end of the second resistance, and the other end of the first resistance is connected by the other end of diode with the second resistance; Voltage-regulating circuit, comprise the 3rd resistance, variable resistance, controlled source of stable pressure and biasing resistor, the other end of the second resistance is connected with the positive pole of controlled source of stable pressure by the 3rd resistance, variable resistance successively, the other end of the second resistance is connected with the control end of controlled source of stable pressure, and one end of biasing resistor is connected with the other end of the second resistance; The negative pole of controlled source of stable pressure and the other end of biasing resistor are all connected with 12V feeder ear; Signal output apparatus, comprises photoelectrical coupler, and the other end of the first resistance is connected with the light-emitting diode positive pole of photoelectrical coupler, and the light-emitting diode negative pole of photoelectrical coupler is connected with 12V feeder ear.The utility model components and parts are few, working stability.
Description
Technical field
The utility model relates to DC-DC power source field, particularly a kind of DC-DC power source output overcurrent short-circuit protection circuit.
Background technology
Direct current output protection circuit major part mentality of designing is sampling, and amplifier compares, and exports and controls.This core is wherein comparison circuit, and more so element multi-line is complicated to realize level with comparison circuit, and failure rate is higher, has a lot of unfavorable factor to production test.DC-DC power source output overcurrent short-circuit protection circuit of the prior art mainly contains following shortcoming: (1) circuit element is many; (2) cost is higher; (3) failure rate is high.
Utility model content
The utility model provides the DC-DC power source output overcurrent short-circuit protection circuit that a kind of structure is simple, cost is low, precision is high, failure response time is short.
For solving the problem, as an aspect of the present utility model, provide a kind of DC-DC power source output overcurrent short-circuit protection circuit, it is characterized in that, comprising: DC-DC output feedack end, 12V feeder ear, earth terminal and the pwm signal control end for controlling DC-DC circuit; Sample circuit, comprises the first resistance, the second resistance and diode, and the first resistance is all connected with DC-DC output feedack end with one end of the second resistance, and the other end of the first resistance is connected by the other end of diode with the second resistance; Voltage-regulating circuit, comprise the 3rd resistance, variable resistance, controlled source of stable pressure and biasing resistor, the other end of the second resistance is connected with the positive pole of controlled source of stable pressure by the 3rd resistance, variable resistance successively, the other end of the second resistance is connected with the control end of controlled source of stable pressure, and one end of biasing resistor is connected with the other end of the second resistance; The negative pole of controlled source of stable pressure and the other end of biasing resistor are all connected with 12V feeder ear; Signal output apparatus, comprise photoelectrical coupler, the other end of the first resistance is connected with the light-emitting diode positive pole of photoelectrical coupler, the light-emitting diode negative pole of photoelectrical coupler is connected with 12V feeder ear, the grounded emitter of photoelectrical coupler, the collector electrode of photoelectrical coupler is connected with pwm signal control end.
Preferably, sample circuit also comprises the first electric capacity and the 4th resistance, and DC-DC output feedack end is connected with the other end of the second resistance with after the 4th resistance by the first electric capacity successively.
Preferably, sample circuit also comprises first voltage-stabiliser tube of voltage stabilizing 12V, and positive pole is connected with earth terminal, and negative pole is connected with 12V feeder ear.
Preferably, DC-DC power source output overcurrent short-circuit protection circuit also comprises delay time adjustment circuit, and delay time adjustment circuit comprises electrochemical capacitor and the 5th resistance, and the other end of the second resistance is connected with 12V feeder ear with the 5th resistance by electrochemical capacitor successively.
Preferably, voltage-regulating circuit also comprises the second electric capacity for absorbing pulse afterflow and the 3rd electric capacity for absorbing pulse afterflow, one end of second electric capacity is connected with the positive pole of controlled source of stable pressure, the other end of the second electric capacity is connected with the control end of controlled source of stable pressure, one end of 3rd electric capacity is connected with the negative pole of controlled source of stable pressure, and the other end of the 3rd electric capacity is connected with the control end of controlled source of stable pressure.
Preferably, DC-DC power source output overcurrent short-circuit protection circuit also comprises second voltage-stabiliser tube of voltage stabilizing 10V, and positive pole is connected with earth terminal, and negative pole is connected with the light-emitting diode positive pole of photoelectrical coupler.
Owing to have employed the technical scheme in the utility model, the utility model structure is simple, components and parts are few, working stability, precision are high, failure response time is short, if once there be fault, out of service so immediately.
Accompanying drawing explanation
Fig. 1 schematically shows structural representation of the present utility model.
Reference numeral in figure: 1, DC-DC output feedack end; 2,12V feeder ear; 3, earth terminal; 4, pwm signal control end; 5, the first resistance; 6, the second resistance; 7, diode; 8, the 3rd resistance; 9, variable resistance; 10, controlled source of stable pressure; 11, biasing resistor; 12, photoelectrical coupler; 13, the first electric capacity; 14, the 4th resistance; 15, the first voltage-stabiliser tube; 16, electrochemical capacitor; 17, the 5th resistance; 18, the second electric capacity; 19, the 3rd electric capacity; 20, the second voltage-stabiliser tube.
Embodiment
Below in conjunction with accompanying drawing, embodiment of the present utility model is described in detail, but the multitude of different ways that the utility model can be defined by the claims and cover is implemented.
Please refer to Fig. 1, the utility model provides a kind of DC-DC power source output overcurrent short-circuit protection circuit, comprising: DC-DC output feedack end 1,12V feeder ear 2, earth terminal 3 and the pwm signal control end 4 for controlling DC-DC circuit; Sample circuit, comprises the first resistance 5, second resistance 6 and diode 7, first resistance 5 is all connected with DC-DC output feedack end 1 with one end of the second resistance 6, and the other end of the first resistance 5 is connected with the other end of the second resistance 6 by diode 7; Voltage-regulating circuit, comprise the 3rd resistance 8, variable resistance 9, controlled source of stable pressure 10 and biasing resistor 11, the other end of the second resistance 6 is connected with the positive pole of controlled source of stable pressure 10 by the 3rd resistance 8, variable resistance 9 successively, the other end of the second resistance 6 is connected with the control end of controlled source of stable pressure 10, and one end of biasing resistor 11 is connected with the other end of the second resistance 6; The negative pole of controlled source of stable pressure 10 and the other end of biasing resistor 11 are all connected with 12V feeder ear 2; Signal output apparatus, comprise photoelectrical coupler 12, the other end of the first resistance 5 is connected with the light-emitting diode positive pole of photoelectrical coupler 12, the light-emitting diode negative pole of photoelectrical coupler 12 is connected with 12V feeder ear 2, the grounded emitter of photoelectrical coupler 12, the collector electrode of photoelectrical coupler 12 is connected with pwm signal control end 4.
The Main Function of sample circuit is that the virtual voltage that DC-DC power source exports is incorporated into the utility model, and diode 7 utilizes unidirectional some feature of diode to prevent electric current adverse current; First resistance 5, second resistance 6 forms sample resistance.
Second resistance 6 is supplied to the positive pole of controlled source of stable pressure 10 after the input voltage of reality being carried out dividing potential drop together with the 3rd resistance 8 in voltage-regulating circuit, variable resistance 9.Biasing resistor 11 is for providing bias voltage to controlled source of stable pressure 10.Controlled source of stable pressure 10 can adjust the voltage of its positive pole and negative pole according to bias voltage, and its output voltage is given with more accurate during electric resistance partial pressure.
Signal output apparatus controls the output of DC-DC power source by pwm signal control end 4 by the output of photoelectrical coupler 12, if the voltage of pwm signal control end 4 is low, so the output of DC-DC power source is closed, otherwise then DC-DC power source exports and recovers normal.In one embodiment, if the voltage of the control end of controlled source of stable pressure 10 is less than 8V, so photoelectrical coupler 12 meeting conducting, thus the level of pwm signal control end 4 can be pulled to zero potential.
Preferably, sample circuit also comprises the first electric capacity 13 and the 4th resistance 14, DC-DC output feedack end 1 successively by being connected with the other end of the second resistance 6 after the first electric capacity 13 and the 4th resistance 14.First electric capacity 13 and the 4th resistance 14 form pulse absorption circuit.
Preferably, sample circuit also comprises first voltage-stabiliser tube 15 of voltage stabilizing 12V, and positive pole is connected with earth terminal 3, and negative pole is connected with 12V feeder ear 2.First voltage-stabiliser tube 15 makes voltage stabilization between 11.7V-12.2V.
Preferably; DC-DC power source output overcurrent short-circuit protection circuit also comprises delay time adjustment circuit; the other end that delay time adjustment circuit comprises electrochemical capacitor 16 and the 5th resistance 17, second resistance 6 is connected with 12V feeder ear 2 with the 5th resistance 17 by electrochemical capacitor successively.Delay time adjustment circuit is mainly used in adjustment time of delay, and after the series connection of the 3rd resistance 8, variable resistance 9, again with the second resistance 6 is divided to normal 11-12V, is to make photoelectrical coupler 12 conducting at nominal conditions.
Preferably, voltage-regulating circuit also comprises the second electric capacity 18 for absorbing pulse afterflow and the 3rd electric capacity 19 for absorbing pulse afterflow, one end of second electric capacity 18 is connected with the positive pole of controlled source of stable pressure 10, the other end of the second electric capacity is connected with the control end of controlled source of stable pressure 10, one end of 3rd electric capacity 19 is connected with the negative pole of controlled source of stable pressure 10, and the other end of the 3rd electric capacity is connected with the control end of controlled source of stable pressure 10.Second electric capacity 18 and the 3rd electric capacity 19 carry out pulse absorb and afterflow to controlled source of stable pressure 10.
Preferably, DC-DC power source output overcurrent short-circuit protection circuit also comprises second voltage-stabiliser tube 20 of voltage stabilizing 10V, and positive pole is connected with earth terminal 3, and negative pole is connected with the light-emitting diode positive pole of photoelectrical coupler 12.
Below in conjunction with Fig. 1, the course of work of the present utility model is described in detail.
The voltage stabilizing of the second voltage-stabiliser tube 20 is 10V, and the voltage stabilizing of the first voltage-stabiliser tube 15 is 12V, just has the reverse voltage of 2V like this at the light-emitting diodes pipe end of photoelectrical coupler 12, thus ensure be at nominal conditions stable can not conducting.If input voltage is reduced to 21.5V, the voltage so after dividing potential drop will lower than 10.3V, and wherein variable resistance 9 is adjustable resistances, magnitude of voltage that thus can be relevant according to the demand adjustment of different client.In one embodiment, 1.5K adjusted to by variable resistance 9, the voltage of the control end of so controlled source of stable pressure 10 is lower than 10V, so the voltage stabilizing output voltage of controlled source of stable pressure 10 can change along with the voltage of control end and change, thus cause the pressure reduction had higher than 2V at the light-emitting diode two ends of photoelectrical coupler 12, so photoelectrical coupler 12 conducting, thus make pwm signal control end 4 step-down.Due to pwm signal control end 4 be the enable pin of the PWM control IC being connected to DC-DC power source to control whether output voltage, therefore, if this point voltage is lowly so export closedown.
Owing to have employed the technical scheme in the utility model; DC-DC power source output overcurrent short-circuit protection circuit structure in the utility model is simple, components and parts are few, working stability, precision are high, failure response time is short; if once there be fault, out of service so immediately.Such as, in one embodiment, if output voltage is lower than 21.5V, so automatic the output of DC-DC power source to be closed, and if by output point voltage higher than 23V, so automatically recover the output voltage of DC-DC power source.In addition; the response time of circuit is considered because the utility model is actual; the mainly bypass effect of electric capacity wherein; almost there is no coupling capacitance; therefore the time of Circuit responce short (being less than 1 millisecond); and cost almost only has the half of traditional DC-DC power source output overcurrent short-circuit protection circuit, also reduces rate of breakdown.
The foregoing is only preferred embodiment of the present utility model, be not limited to the utility model, for a person skilled in the art, the utility model can have various modifications and variations.All within spirit of the present utility model and principle, any amendment done, equivalent replacement, improvement etc., all should be included within protection range of the present utility model.
Claims (6)
1. a DC-DC power source output overcurrent short-circuit protection circuit, is characterized in that, comprising:
DC-DC output feedack end (1), 12V feeder ear (2), earth terminal (3) and the pwm signal control end (4) for controlling DC-DC circuit;
Sample circuit, comprise the first resistance (5), the second resistance (6) and diode (7), described first resistance (5) is all connected with described DC-DC output feedack end (1) with one end of described second resistance (6), and the other end of described first resistance (5) is connected with the other end of described second resistance (6) by described diode (7);
Voltage-regulating circuit, comprise the 3rd resistance (8), variable resistance (9), controlled source of stable pressure (10) and biasing resistor (11), the described other end of described second resistance (6) is connected with the positive pole of described controlled source of stable pressure (10) by described 3rd resistance (8), variable resistance (9) successively, the described other end of described second resistance (6) is connected with the control end of described controlled source of stable pressure (10), and one end of described biasing resistor (11) is connected with the described other end of described second resistance (6); The negative pole of described controlled source of stable pressure (10) and the other end of described biasing resistor (11) are all connected with described 12V feeder ear (2);
Signal output apparatus, comprise photoelectrical coupler (12), the described other end of described first resistance (5) is connected with the light-emitting diode positive pole of described photoelectrical coupler (12), the light-emitting diode negative pole of described photoelectrical coupler (12) is connected with described 12V feeder ear (2), the grounded emitter of described photoelectrical coupler (12), the collector electrode of described photoelectrical coupler (12) is connected with described pwm signal control end (4).
2. DC-DC power source output overcurrent short-circuit protection circuit according to claim 1; it is characterized in that; described sample circuit also comprises the first electric capacity (13) and the 4th resistance (14), and described DC-DC output feedack end (1) is connected with the described other end of described second resistance (6) with the 4th resistance (14) afterwards by described first electric capacity (13) successively.
3. DC-DC power source output overcurrent short-circuit protection circuit according to claim 1; it is characterized in that; described sample circuit also comprises first voltage-stabiliser tube (15) of voltage stabilizing 12V; positive pole is connected with described earth terminal (3), and negative pole is connected with described 12V feeder ear (2).
4. DC-DC power source output overcurrent short-circuit protection circuit according to claim 1; it is characterized in that; described DC-DC power source output overcurrent short-circuit protection circuit also comprises delay time adjustment circuit; described delay time adjustment circuit comprises electrochemical capacitor (16) and the 5th resistance (17), and the described other end of described second resistance (6) is connected with described 12V feeder ear (2) with described 5th resistance (17) by described electrochemical capacitor successively.
5. DC-DC power source output overcurrent short-circuit protection circuit according to claim 1, it is characterized in that, described voltage-regulating circuit also comprises the second electric capacity (18) for absorbing pulse afterflow and the 3rd electric capacity (19) for absorbing pulse afterflow, one end of described second electric capacity (18) is connected with the positive pole of described controlled source of stable pressure (10), the other end of described second electric capacity is connected with the control end of described controlled source of stable pressure (10), one end of described 3rd electric capacity (19) is connected with the negative pole of described controlled source of stable pressure (10), the other end of described 3rd electric capacity is connected with the control end of described controlled source of stable pressure (10).
6. DC-DC power source output overcurrent short-circuit protection circuit according to claim 1; it is characterized in that; described DC-DC power source output overcurrent short-circuit protection circuit also comprises second voltage-stabiliser tube (20) of voltage stabilizing 10V; positive pole is connected with described earth terminal (3), and negative pole is connected with the light-emitting diode positive pole of described photoelectrical coupler (12).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520463173.7U CN204720966U (en) | 2015-07-01 | 2015-07-01 | DC-DC power source output overcurrent short-circuit protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520463173.7U CN204720966U (en) | 2015-07-01 | 2015-07-01 | DC-DC power source output overcurrent short-circuit protection circuit |
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| Publication Number | Publication Date |
|---|---|
| CN204720966U true CN204720966U (en) | 2015-10-21 |
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|---|---|---|---|
| CN201520463173.7U Expired - Fee Related CN204720966U (en) | 2015-07-01 | 2015-07-01 | DC-DC power source output overcurrent short-circuit protection circuit |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106155261A (en) * | 2016-08-24 | 2016-11-23 | 柳州鹏达科技有限责任公司 | Computer power supply system protection circuit |
-
2015
- 2015-07-01 CN CN201520463173.7U patent/CN204720966U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106155261A (en) * | 2016-08-24 | 2016-11-23 | 柳州鹏达科技有限责任公司 | Computer power supply system protection circuit |
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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: 20151021 Termination date: 20160701 |
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| CF01 | Termination of patent right due to non-payment of annual fee |