CN205453078U - Current foldback circuit and constant voltage power supply - Google Patents
Current foldback circuit and constant voltage power supply Download PDFInfo
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- CN205453078U CN205453078U CN201521080500.7U CN201521080500U CN205453078U CN 205453078 U CN205453078 U CN 205453078U CN 201521080500 U CN201521080500 U CN 201521080500U CN 205453078 U CN205453078 U CN 205453078U
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Abstract
The utility model relates to a current foldback circuit, including sampling resistor, the adjustable reference power supply of first three -terminal, voltage sharing unit, filter capacitance, control switch and be used for controlling the controller of output current signal, the adjustable reference power supply 's of first three -terminal positive pole is connected through sampling resistor and output circuit's negative pole, the adjustable reference power supply 's of first three -terminal negative pole and the anodal of output circuit are connected, the adjustable reference power supply 's of first three -terminal reference edge is connected with voltage sharing unit, filter capacitance, control switch, controller electricity in proper order. Provide a constant voltage power supply in addition. Among above -mentioned current foldback circuit and the constant voltage power supply, handle through adjustable reference power supply of first three -terminal and voltage sharing unit's partial pressure processing and filter capacitance's filtering, after control switch detection output current exceedes the settlement current value, transfer the controller with control signal, by controller control output, carry out overcurrent protection to output circuit. Above -mentioned current foldback circuit design is simple, the interference killing feature is strong, and the overcurrent protection precision is high.
Description
Technical field
This utility model is related to protection of circuit field, particularly relates to current foldback circuit and regulated power supply.
Background technology
Along with the raising of people's living standard, the electronic product such as electronic equipment, electronic machine becomes a requisite part in people's life gradually.Electric energy is closely bound up with our life, the properly functioning electric energy that all be unable to do without of the various electronic product such as electronic equipment, electronic machine, and every kind of electronic product has the biggest dependency to the voltage of power supply.
In the use of electronic product; often can encounter circuit and cross the situation (serious picture short circuit) of stream; now would generally in the alternating current circuit that civil power or other alternating current power supply (electromotor) export Design of Transformer change-over circuit; limit the output electric current of power supply by transformator change-over circuit or reduce output, reaching the purpose of overcurrent protection.But when being controlled the output electric current of power supply by transformator change-over circuit, when inputting 90～264 volts due to full voltage range, high and low pressure input current is different so that over-current protection point is inconsistent, difference compared with big, error is big；Even if the temperature characterisitic of electronic devices and components precision of mistake flow point in the case of identical input voltage also can produce change simultaneously, it is easily subject to the impact of external environment.
Utility model content
Based on this, it is necessary to low for the precision crossing flow point, to be vulnerable to external environment impact problem, it is provided that a kind of current foldback circuit and regulated power supply.
A kind of current foldback circuit, carries out overcurrent protection to the current signal of output circuit, switchs and for controlling the controller of output current signal including sampling resistor, the one or three end adjustable reference power supply, partial pressure unit, filter capacitor, control；
The sampled resistance of anode of described one or three end adjustable reference power supply is connected with the negative pole of described output circuit；The negative electrode of described one or three end adjustable reference power supply is connected with the positive pole of described output circuit；The reference edge of described one or three end adjustable reference power supply electrically connects with described partial pressure unit, filter capacitor, control switch, controller successively.
Wherein in an embodiment, described current foldback circuit also includes current-limiting resistance, and the negative electrode of described one or three end adjustable reference power supply connects through the positive pole of output circuit described in described current-limiting resistance.
Wherein in an embodiment, described partial pressure unit includes the 3rd resistance and the 4th resistance；First end of described 3rd resistance is connected with the reference edge of described one or three end adjustable reference power supply, and the second end of described 3rd resistance is connected with described 4th resistance, filter capacitor respectively；The other end ground connection of described 4th resistance.
Wherein in an embodiment, the first end of described filter capacitor is connected with the second end, the control switch of described 3rd resistance respectively；Second end ground connection of described filter capacitor.
Wherein in an embodiment, described control switch is the two or three end adjustable reference power supply, and the two ends of described filter capacitor are connected with anode, the reference edge of described two or three end adjustable reference power supply respectively；The plus earth of described two or three end adjustable reference power supply；The negative electrode of described two or three end adjustable reference power supply is connected with described controller.
Wherein in an embodiment, the described switch that controls is for NPN type triode, and the two ends of described filter capacitor are connected with base stage, the emitter stage of described NPN type triode respectively；The grounded emitter of described NPN type triode；The colelctor electrode of described NPN type triode is connected with described controller.
Wherein in an embodiment, the described switch that controls is for field effect transistor, and the two ends of described filter capacitor are connected with grid, the drain electrode of described field effect transistor respectively；The source ground of described field effect transistor；The drain electrode of described field effect transistor is connected with described controller.
Wherein in an embodiment, described one or three end adjustable reference power supply, the model of the two or three end adjustable reference power supply are AZ432ANTR-E1.
Further, it would be desirable to provide a kind of regulated power supply, including current rectifying and wave filtering circuit, transformator conversion circuit, above-mentioned current foldback circuit and ON-OFF control circuit, described current rectifying and wave filtering circuit, pressure swing reforming circuit, current foldback circuit and ON-OFF control circuit are sequentially connected electrically；Described pressure swing reforming circuit is also connected with described ON-OFF control circuit.
Wherein in an embodiment, described current foldback circuit is connected with described ON-OFF control circuit through photo-coupler.
In above-mentioned current foldback circuit and regulated power supply; the signal of telecommunication exported by sampling resistor collection, owing to the reference voltage of the one or three end adjustable reference power supply is relatively low, corresponding partial pressure unit branch pressure voltage value is relatively low; decrease the voltage drop value in output circuit, thus improve the precision of voltage regulation of output；Filter capacitor filters the capacity of resisting disturbance adding output circuit to the spike of the signal of telecommunication；After control switch detects to cause output electric current to exceed setting current value due to short circuit or other reasons, produce control signal and feed back to controller, controller control output, output circuit is carried out overcurrent protection.In above-mentioned current foldback circuit, circuit design is simple, low cost, capacity of resisting disturbance are strong, and voltage accuracy is high and then overcurrent protection precision is high simultaneously.
Accompanying drawing explanation
Fig. 1 is current foldback circuit schematic diagram；
Fig. 2 is the current foldback circuit schematic diagram in an embodiment；
Fig. 3 is the electrical symbol figure of three end adjustable reference power supplys；
Fig. 4 is the current foldback circuit schematic diagram in an embodiment；
Fig. 5 is regulated power supply frame diagram.
Detailed description of the invention
For the ease of understanding this utility model, below with reference to relevant drawings, this utility model is described more fully.Accompanying drawing gives preferred embodiment of the present utility model.But, this utility model can realize in many different forms, however it is not limited to embodiment described herein.On the contrary, providing the purpose of these embodiments is to make the understanding to disclosure of the present utility model more thorough comprehensively.
Unless otherwise defined, all of technology used herein and scientific terminology are identical with belonging to the implication that those skilled in the art of the present utility model are generally understood that.It is intended merely to describe the purpose of specific embodiment at term used in the description of the present utility model herein, it is not intended that limit this utility model.Term as used herein "and/or" includes the arbitrary and all of combination of one or more relevant Listed Items.
As shown in Figure 1 for current foldback circuit schematic diagram; in figure, current foldback circuit 10 is arranged between the outfan of output circuit 20; output electric current for detecting output circuit 20 produces over-current signal when exceeding setting value, and the over-current signal produced is carried out overcurrent protection.Current foldback circuit 10 includes sampling resistor R1, the one or three end adjustable reference power supply U1, partial pressure unit 110, filter capacitor C1, controls switch 120 and for controlling the controller 130 of output current signal.The anode sampled resistance R1 of the one or three end adjustable reference power supply U1 is connected with the negative pole of output circuit；The negative electrode of the one or three end adjustable reference power supply U1 is connected with the positive pole of output circuit；The reference edge of the one or three end adjustable reference power supply U1 and negative electrode short circuit.The reference edge of the one or three end adjustable reference power supply U1 electrically connects with partial pressure unit 110, filter capacitor C1, control switch 120, controller 130 successively.
In the present embodiment, current foldback circuit 10 also includes that current-limiting resistance R2, the negative electrode of the one or three end adjustable reference power supply U1 are connected through the positive pole of current-limiting resistance R2 with output circuit 10.
As shown in Figure 2 for current protecting circuit in an embodiment, wherein, partial pressure unit 110 includes the 3rd resistance R3 and the 4th resistance R4；First end of the 3rd resistance R3 and the reference edge of the one or three end adjustable reference power supply U1 connect, and second end of the 3rd resistance R3 is connected with the 4th resistance R4, filter capacitor C1 respectively；The other end ground connection of the 4th resistance R4.First end of filter capacitor C1 is connected with the second end, the control end of control switch 120 of the 3rd resistance R3 respectively；The second end ground connection of filter capacitor C2.
In the present embodiment, when the unexpected powering load of output circuit, sampling resistor R1 is easy to due to voltage spikes occurs, and causes the control of over-current signal to switch 120 misoperations；Increase filter capacitor C2 just can be filtered by due to voltage spikes, increase the capacity of resisting disturbance of whole circuit.
In the present embodiment, controlling switch 120 is the two or three end adjustable reference power supply U2.The two ends of filter capacitor C1 are connected with anode, the reference edge of the two or three end adjustable reference power supply U2 respectively；The plus earth of the two or three end adjustable reference power supply U2；The negative electrode of the two or three end adjustable reference power supply U2 is connected with controller 130, and over-current signal is transferred to controller 130.
The one or three end adjustable shunt reference power supply U1 in the present embodiment, the model of the two or three end adjustable shunt reference power supply U2 are AZ432ANTR-E1, and with reference to Fig. 3, in figure, letter A represents the anode of three end adjustable shunt reference power supplies；Letter K represents the negative electrode of three end adjustable shunt reference power supplies；Letter r represents the reference edge of three end adjustable shunt reference power supplies.The voltage stabilization value of the reference edge that the three end adjustable shunt reference power supplies selecting model to be AZ432ANTR-E1 are because three end adjustable shunt reference power supplies is 1.25V, and its voltage stabilization value is relatively low, and range of error is between-0.5%～+0.5%, and range of error is little.Then the branch pressure voltage of the 3rd resistance R3 in partial pressure unit 110 and the 4th resistance R4 reduces the most therewith；In like manner, sampling resistor R1 can also reduce.When by identical electric current, sampling resistor R1, the 3rd resistance R3, the pressure drop of the 4th resistance R4 reduce, thus improve the precision of voltage regulation of output.In view of sampling resistor R1, the 3rd resistance R3, the value precision of the 4th resistance R4 can affect the precision of current foldback circuit, in the present embodiment, the value accuracy selection resistance less than or equal to 1% of sampling resistor R1, the 3rd resistance R3, the 4th resistance R4.
Further, by divider resistance (the 3rd resistance R3 and the 4th resistance R4) dividing potential drop in partial pressure unit 110, and by the voltage on the voltage of current-limiting resistance R2 collection terminal and the 3rd resistance R3, export the reference edge of the two or three end adjustable shunt reference power supply U2.When exporting electric current and being gradually increased; the voltage of the reference edge of the two or three end adjustable shunt reference power supply U2 can reach its running voltage; then negative electrode and the anode of the two or three end adjustable shunt reference power supply U2 will turn on; and its over-current signal is transferred to controller 130; controlled output by controller 130, output circuit is carried out overcurrent protection.
The current foldback circuit for an embodiment as shown in Figure 4, wherein controlling switch 120 is NPN type triode Q1, and the two ends of filter capacitor C1 are connected with base stage, the emitter stage of NPN type triode Q1 respectively；The grounded emitter of NPN type triode Q1；The colelctor electrode of NPN type triode Q1 is connected with controller 130.When voltage between the 3rd resistance R3 and the 4th resistance R4 is more than 0.7V, NPN type triode Q1 turns on, and its over-current signal is transferred to controller 130, controller 130 control output, output circuit is carried out overcurrent protection.
In other embodiments, controlling switch can also be field effect transistor (not shown), and the two ends of filter capacitor are connected with grid, the drain electrode of field effect transistor respectively；The source ground of field effect transistor；The drain electrode of field effect transistor is connected with controller.
Regulated power supply frame diagram as shown in Figure 5, including current rectifying and wave filtering circuit 30, transformator conversion circuit 40, current foldback circuit 10 and ON-OFF control circuit 50；Current rectifying and wave filtering circuit 30, pressure swing reforming circuit 40, current foldback circuit 10 and ON-OFF control circuit 50 are sequentially connected electrically, and ON-OFF control circuit 50 is also connected with transformator change-over circuit 40.The input AC signal of telecommunication is input to the input of current rectifying and wave filtering circuit 30 by electric fuse.Current rectifying and wave filtering circuit 30 realizes rectification by BD1 rectifier bridge in this embodiment.What rectified filter circuit 30 produced after processing is similar DC voltage, by transformator change-over circuit 40, input voltage is being adjusted to suitable output voltage.Current foldback circuit 10 detection output electric current, when exporting electric current and exceeding setting value, produces over-current signal and feeds back to ON-OFF control circuit 50 by photo-coupler.Transformator change-over circuit 40 uses pwm signal to control ON-OFF control circuit 50 simultaneously, and the Duty ratio control of pwm signal exports suitable power.
In other embodiments, output circuit is not limited to regulated power supply output circuit, it can also be other output circuit, as exported signal source or the outfan product of other output direct current signal of direct current signal, when this output electric current is more than setting value, produce a signal and feed back to controller, cut off input power or reduce output etc..
Each technical characteristic of embodiment described above can combine arbitrarily, for making description succinct, the all possible combination of each technical characteristic in above-described embodiment is not all described, but, as long as the combination of these technical characteristics does not exist contradiction, all it is considered to be the scope that this specification is recorded.
Embodiment described above only have expressed several embodiments of the present utility model, and it describes more concrete and detailed, but therefore can not be interpreted as the restriction to utility model patent scope.It should be pointed out that, for the person of ordinary skill of the art, without departing from the concept of the premise utility, it is also possible to make some deformation and improvement, these broadly fall into protection domain of the present utility model.Therefore, the protection domain of this utility model patent should be as the criterion with claims.
Claims (10)
1. a current foldback circuit, carries out overcurrent protection to the current signal of output circuit, it is characterised in that include that sampling resistor, the one or three end adjustable reference power supply, partial pressure unit, filter capacitor, control switch and for controlling the controller of output current signal；
The sampled resistance of anode of described one or three end adjustable reference power supply is connected with the negative pole of described output circuit；The negative electrode of described one or three end adjustable reference power supply is connected with the positive pole of described output circuit；The reference edge of described one or three end adjustable reference power supply electrically connects with described partial pressure unit, filter capacitor, control switch, controller successively.
Current foldback circuit the most according to claim 1, it is characterised in that described current foldback circuit also includes current-limiting resistance, the negative electrode of described one or three end adjustable reference power supply connects through the positive pole of output circuit described in described current-limiting resistance.
Current foldback circuit the most according to claim 1, it is characterised in that described partial pressure unit includes the 3rd resistance and the 4th resistance；First end of described 3rd resistance is connected with the reference edge of described one or three end adjustable reference power supply, and the second end of described 3rd resistance is connected with described 4th resistance, filter capacitor respectively；The other end ground connection of described 4th resistance.
Current foldback circuit the most according to claim 3, it is characterised in that the first end of described filter capacitor is connected with the second end, the control switch of described 3rd resistance respectively；Second end ground connection of described filter capacitor.
Current foldback circuit the most according to claim 1, it is characterised in that described control switch is the two or three end adjustable reference power supply, and the two ends of described filter capacitor are connected with anode, the reference edge of described two or three end adjustable reference power supply respectively；The plus earth of described two or three end adjustable reference power supply；The negative electrode of described two or three end adjustable reference power supply is connected with described controller.
Current foldback circuit the most according to claim 1, it is characterised in that described control switch is NPN type triode, and the two ends of described filter capacitor are connected with base stage, the emitter stage of described NPN type triode respectively；The grounded emitter of described NPN type triode；The colelctor electrode of described NPN type triode is connected with described controller.
Current foldback circuit the most according to claim 1, it is characterised in that described control switch is field effect transistor, the two ends of described filter capacitor are connected with grid, the drain electrode of described field effect transistor respectively；The source ground of described field effect transistor；The drain electrode of described field effect transistor is connected with described controller.
Current foldback circuit the most according to claim 5, it is characterised in that described one or three end adjustable reference power supply, the model of the two or three end adjustable reference power supply are AZ432ANTR-E1.
9. a regulated power supply; including current rectifying and wave filtering circuit, transformator conversion circuit, current foldback circuit as described in any one in claim 1～8 and ON-OFF control circuit, described current rectifying and wave filtering circuit, pressure swing reforming circuit, current foldback circuit and ON-OFF control circuit are sequentially connected electrically；Described pressure swing reforming circuit is also connected with described ON-OFF control circuit.
Regulated power supply the most according to claim 9, it is characterised in that described current foldback circuit is connected with described ON-OFF control circuit through photo-coupler.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201521080500.7U CN205453078U (en) | 2015-12-22 | 2015-12-22 | Current foldback circuit and constant voltage power supply |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201521080500.7U CN205453078U (en) | 2015-12-22 | 2015-12-22 | Current foldback circuit and constant voltage power supply |
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| CN205453078U true CN205453078U (en) | 2016-08-10 |
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| CN201521080500.7U Active CN205453078U (en) | 2015-12-22 | 2015-12-22 | Current foldback circuit and constant voltage power supply |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109521828A (en) * | 2018-12-29 | 2019-03-26 | 惠州华科电器有限公司 | Linear voltage-stabilizing circuit |
| CN111327020B (en) * | 2020-03-10 | 2020-12-25 | 珠海格力电器股份有限公司 | Power supply protection circuit and power supply |
-
2015
- 2015-12-22 CN CN201521080500.7U patent/CN205453078U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109521828A (en) * | 2018-12-29 | 2019-03-26 | 惠州华科电器有限公司 | Linear voltage-stabilizing circuit |
| CN111327020B (en) * | 2020-03-10 | 2020-12-25 | 珠海格力电器股份有限公司 | Power supply protection circuit and power supply |
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| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CP03 | Change of name, title or address |
Address after: 518000 Nanshan medical equipment Industrial Park, No. 1019, Nanshan Road, Nanshan District, Shenzhen, Guangdong Province, A211-A213 Patentee after: Shenzhen Hai Yun new energy Co.,Ltd. Address before: 518000 Nanshan District, Guangdong, South China Sea Road, No. 1019 Nanshan medical equipment Industrial Park, A408, B401-403, Patentee before: SHENZHEN LANDING TECHNOLOGY Co.,Ltd. |
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| CP03 | Change of name, title or address | ||
| CP03 | Change of name, title or address |
Address after: 518000 Building 201, Gongjin Electronics 3 #, Shatian Community, Kengzi Street, Pingshan District, Shenzhen, Guangdong Province Patentee after: Shenzhen Haiyun Testing Co.,Ltd. Address before: 518000 Nanshan Medical Instrument Industrial Park 1019, Nanhai Road, Nanshan District, Shenzhen, Guangdong, A211-A213 Patentee before: Shenzhen Hai Yun new energy Co.,Ltd. |
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| CP03 | Change of name, title or address |