CN205544195U - Current foldback circuit and power supply - Google Patents
Current foldback circuit and power supply Download PDFInfo
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- CN205544195U CN205544195U CN201620251694.0U CN201620251694U CN205544195U CN 205544195 U CN205544195 U CN 205544195U CN 201620251694 U CN201620251694 U CN 201620251694U CN 205544195 U CN205544195 U CN 205544195U
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Abstract
The utility model provides a current foldback circuit, including the first switch element, the 2nd switch element, first resistance, second resistance, third resistance and diode. The first switch element's first control end a via grounding, first control end still are connected via third resistance and first route end electricity, and first route end is connected via second resistance and power input end electricity, and the alternate path end is connected with power output end electricity. The 2nd switch element's second control end is connected via second resistance and third route end electricity, and third route end is connected with power input end electricity, and fourth route end is connected with the positive pole electricity of diode, and the negative pole of diode is connected with a switch element's first control end electricity. The utility model discloses still provide power supply. The utility model discloses a current foldback circuit and power supply can realize overcurrent protection's function, simple structure, and the flexibility is high, with low costs.
Description
Technical field
This utility model relates to power supply technique field, particularly relates to current foldback circuit and has described mistake
The power supply of stream protection circuit.
Background technology
Current vehicle active antenna is substantially by micro-control unit (Micro Controller
Unit, MCU) control the conducting powered of active antenna and disconnection, and a lot of vehicle active antenna
Electric supply installation does not possess overcurrent protection function, or directly with a power supply possessing overcurrent protection function
Chip realizes the function of overcurrent protection.
But, owing to vehicle active antenna is producing or in test process, is being required for constantly plugging
Antenna, easily causes aerial head short circuit, if vehicle active antenna is powered does not possesses the merit of overcurrent protection
Can, it is easy to cause the components and parts in mobile unit to burn；If directly using and possessing overcurrent protection merit
The power supply chip of energy, then owing to the current limliting size of power supply chip is fixing, it is thus impossible to reach
The restriction electric current that the various design of vehicle active antenna needs, motility is low, and its cost is high.
Utility model content
In view of this, this utility model purpose is to provide a kind of current foldback circuit and power supply,
Being capable of the function of overcurrent protection, simple in construction is, and motility is high, low cost.
Specifically, this utility model embodiment provides a kind of current foldback circuit, and described circuit includes:
First switch element, second switch element, the first resistance, the second resistance, the 3rd resistance and diode；
Described first switch element include the first path terminal, alternate path end and first control end, described first
Control end is via described first resistance eutral grounding, and described first controls end also via described 3rd resistance and institute
Stating the first path terminal electrical connection, described first path terminal is via described second resistance and power input electricity
Connecting, described alternate path end electrically connects with power output end；Described second switch element includes the 3rd
Path terminal, fourth passage end and second control end, described second control end via described second resistance with
Described third path end electrically connects, and described third path end electrically connects with described power input, described
Fourth passage end electrically connects with the anode of described diode, and the negative electrode of described diode is opened with described first
Close described the first of element and control end electrical connection；Wherein, the forward voltage drop of described diode less than or etc.
Conducting voltage in described second switch element.
Preferably, described current foldback circuit also includes the 4th resistance, the first end of described 4th resistance
Electrically connecting with the second control end of described second switch element, the second end of described 4th resistance is with described
First path terminal electrical connection of the first switch element.
Preferably, described first switch element and described second switch element are PNP type triode.
This utility model embodiment also provides for a kind of power supply, and described power supply includes as mentioned above
Current foldback circuit.
Preferably, described power supply also includes that control circuit, described control circuit include: the 3rd opens
Close element, the 5th resistance and the 6th resistance；Described 3rd switch element include fifth passage end, the 6th
Path terminal and the 3rd controls end, and the described 3rd controls end receives enable signal via described 5th resistance,
Described fifth passage end controls end via described 6th resistance with the described 3rd and electrically connects, described five-way
Terminal ground connection, described clematis stem terminal is via described in described first resistance and described first switch element
First controls end electrical connection.
Preferably, described power supply also includes that filter circuit, described filter circuit include: the first electricity
Sense, the second inductance, the 3rd inductance and electric capacity；First end of described first inductance inputs with described power supply
End electrical connection, the second end of described first inductance electrically connects with the first end of described second inductance, described
Second end of the second inductance electrically connects with the described third path end of described second switch element, and described
First end of three inductance electrically connects with the second end of described first inductance, the second end of described 3rd inductance
Electrically connect with the first end of described electric capacity, the second end ground connection of described electric capacity.
The present embodiment provide current foldback circuit and power supply, by second switch element, first
Resistance, the second resistance, the 3rd resistance and diode just can reliably control the break-make of the first switch element,
Thus realize the function of overcurrent protection, and simple in construction, additionally can be by arranging different resistance values
Second resistance or the resistance value of regulation the second resistance, obtain different size of current value, thus meet
The function of the overcurrent protection of different current needs, motility is high, low cost.
The present embodiment provide for allowing the above and other objects, features and advantages of the present utility model can be more
Become apparent, preferred embodiment cited below particularly, and coordinate institute's accompanying drawings, be described in detail below.
Accompanying drawing explanation
The signal of the circuit structure of the current foldback circuit that Fig. 1 provides for this utility model first embodiment
Figure.
The signal of the circuit structure of the current foldback circuit that Fig. 2 provides for this utility model the second embodiment
Figure.
The schematic diagram of the circuit structure of the power supply that Fig. 3 provides for this utility model one embodiment.
Detailed description of the invention
By further illustrating that this utility model is by the realization expection technological means taked of purpose and merit
Effect, below in conjunction with accompanying drawing and preferred embodiment, to according to the current foldback circuit that the utility model proposes
And the detailed description of the invention of power supply, method, step, structure, feature and effect, describe in detail
As rear.
About of the present utility model aforementioned and other technology contents, feature and effect, coordinate ginseng following
Examine in the detailed description of graphic preferred embodiment and can clearly present.By detailed description of the invention
Illustrate, when technological means and the effect can taked this utility model by reaching expection purpose is able to more
Add and go deep into and concrete understanding, but institute's accompanying drawings is only to provide reference and purposes of discussion, is not used for
This utility model is any limitation as.
Refer to the current foldback circuit 10 that Fig. 1, Fig. 1 provide for this utility model first embodiment
The schematic diagram of circuit structure.As it is shown in figure 1, current foldback circuit 10 includes the first switch element
T1, second switch element T2, the first resistance R1, the second resistance R2, the 3rd resistance R3 and two poles
Pipe D1.
Specifically, the first switch element T1 includes that the first path terminal, alternate path end and first control
End, the first control end is via the first resistance R1 ground connection, and first controls end also via the 3rd resistance R3
Electrically connecting with the first path terminal, the first path terminal is via the second resistance R2 and power input Vin electricity
Connecting, alternate path end electrically connects with power output end Vout.
Second switch element T2 include third path end, fourth passage end and second control end, second
Control end to electrically connect with third path end via the second resistance R2, third path end and power input
Vin electrically connect, fourth passage end electrically connects with the anode of diode D1, the negative electrode of diode D1 and
The first control end electrical connection of the first switch element T1.
Wherein, the forward voltage drop of the diode D1 electric conduction less than or equal to second switch element T2
Pressure Vbe (figure does not indicates).
Specifically, in the present embodiment, the first switch element T1 and second switch element T2 can but
It is not limited to be PNP type triode.Specifically, the first control end and the of the first switch element T1
Two switch element T2 second control end be base stage, first path terminal of the first switch element T1 with
The third path end of second switch element T2 is emitter stage, the alternate path of the first switch element T1
End is colelctor electrode with the fourth passage end of second switch element T2.But this utility model is not with this
Be limited, the first switch element T1 or second switch element T2 at least one can also utilize other
The switch element of type such as metal-oxide-semiconductor realizes.
Specifically, in the present embodiment, it is less than second when the pressure drop of the both end voltage of the second resistance R2
During conducting voltage Vbe of switch element T2, second switch element T2 turns off.Now, first open
The voltage Vb1 of the first control end closing element T1 is less than first path terminal of the first switch element T1
Voltage Ve1 time, the first switch element T1 conducting so that power output end Vout and power supply input
End Vin conducting, so that power output end Vout exports supply voltage.
When the pressure drop of the both end voltage of the second resistance R2 is more than or equal to the conducting of second switch element T2
During voltage Vbe, when the pressure drop of the i.e. second resistance R2 meets Imax*R >=Vbe, wherein, Imax
For flowing through the maximum current value of the second resistance R2 in current foldback circuit 10, R is the second resistance R2
Resistance value, second switch element T2 turn on.Thus obtain the third path of second switch element T2
The voltage Ve2 of end is equal with the voltage Vc2 of fourth passage end.Additionally, due to diode D1 is just
To pressure drop conducting voltage Vbe less than or equal to second switch element T2, the i.e. forward of diode D1
The pressure drop pressure drop less than or equal to the second resistance R2, the now first control end of the first switch element T1
Voltage Vb1 more than or equal to the voltage Ve1 of the first path terminal of the first switch element T1, thus
Making the first switch element T1 turn off, power output end Vout and power input Vin disconnects, and then
Make power output end Vout not export supply voltage, and realize the effect of overcurrent protection.
It follows that in the present embodiment, by second switch element T2, the first resistance R1,
Two resistance R2, the 3rd resistance R3 and diode D1 just can reliably control the first switch element T1
Break-make, thus realize the function of overcurrent protection, simple in construction, additionally can be by arranging difference
Second resistance R2 of resistance value or the resistance value of regulation the second resistance R2, obtain different size of
Current value, thus meet the function of the overcurrent protection of different current needs, motility is high, low cost.
Please join the current foldback circuit 10 ' that Fig. 2, Fig. 2 provide for this utility model the second embodiment
The schematic diagram of circuit structure.As in figure 2 it is shown, in this utility model one embodiment, overcurrent protection
Structure and the principle of circuit 10 ' are essentially identical with the structure of current foldback circuit 10 and principle, difference
Place is only in that current foldback circuit 10 ' also includes the 4th resistance R4, to play the effect of current limliting.Its
In, first end of the 4th resistance R4 electrically connects with the second control end of second switch element T2, and the 4th
Second end of resistance R4 and the first path terminal electrical connection of the first switch element T1.
The electrical block diagram of the power supply 100 that Fig. 3 provides for this utility model one embodiment.
As it is shown on figure 3, power supply 100 includes current foldback circuit 10 ', control circuit 20 and filtered electrical
Road 30.Current foldback circuit 10 ' and control circuit 20, filter circuit 30 and power output end Vout
Connect.Filter circuit 30 is also connected with power input Vin.
Specifically, in the present embodiment, vehicle active sky is supplied voltage to power supply 100
Illustrating as a example by line, but be not limited to this, the most in other embodiments, power supply 100 is also
The device that can give other needs power supplies such as mobile phone, computer provides supply voltage.
Wherein, the particular circuit configurations of current foldback circuit 10 ' is not as it has been described above, repeat them here.
Specifically, control circuit 20 includes the 3rd switch element T3, the 5th resistance R5 and the 6th electricity
Resistance R6.Specifically, the 3rd switch element T3 includes fifth passage end, clematis stem terminal and the 3rd control
End processed, the 3rd controls end receives via the 5th resistance R5 and enables signal EN, and fifth passage end is via the
Six resistance R6 and the 3rd control end electrical connection, fifth passage end ground connection simultaneously, clematis stem terminal via
The first control end electrical connection of the first resistance R1 and the first switch element T1.Wherein, signal is enabled
EN is generated and sent by micro-control unit (Micro Controller Unit, MCU) (not shown)
To the 3rd control end of the 3rd switch element T3, but it is not limited to this.
Specifically, in the present embodiment, the 3rd switch element T3 is NPN type triode.3rd opens
The 3rd control end closing element T3 is base stage, and the fifth passage end of the 3rd switch element T3 is emitter stage,
The clematis stem terminal of the 3rd switch element T3 is colelctor electrode.
Specifically, filter circuit 30 includes the first inductance L1, the second inductance L2, the 3rd inductance L3
And an electric capacity C1.Wherein, first end of the first inductance L1 electrically connects with power input Vin, the
Second end of one inductance L1 and the first end electrical connection of the second inductance L2, the second of the second inductance L2
End electrically connects with the third path end of second switch element T2, first end and first of the 3rd inductance L3
The second end electrical connection of inductance L1, second end of the 3rd inductance L3 is electrically connected with first end of electric capacity C1
Connect, the second end ground connection of electric capacity C1.
Specifically, in the present embodiment, do not receive when the 3rd control end of the 3rd switch element T3
During the enable signal EN sent to micro-control unit, the 3rd switch element T3 turns off, thus controls
First switch element T1 turns off, and then power output end Vout and power input Vin is disconnected,
So that vehicle active antenna can not get supply voltage from power output end Vout.
When the 3rd control end of the 3rd switch element T3 receives micro-control unit via the 5th resistance R5
After the enable signal EN sent, the 3rd switch element T3 conducting, so that the first switch element T1
Can turn on.When the pressure drop of the both end voltage of the second resistance R2 is less than the conducting of second switch element T2
During voltage Vbe, second switch element T2 turns off, so that first control of the first switch element T1
The voltage Ve1 of the voltage Vb1 of end processed first path terminal less than the first switch element T1, first opens
Closing element T1 conducting, now vehicle active antenna obtains supply voltage from power output end Vout.Enter
One step ground, when the pressure drop of the both end voltage of the second resistance R2 is more than or equal to second switch element T2
Conducting voltage Vbe time, second switch element T2 turns on, thus obtains second switch element T2
The voltage Ve2 of third path end equal with the voltage Vc2 of fourth passage end.Additionally, due to two poles
The forward voltage drop of pipe D1 conducting voltage Vbe less than or equal to second switch element T2, say, that
The pressure drop less than or equal to the second resistance R2 of the forward voltage drop of diode D1.Now the first switch unit
The voltage Vb1 of the first control end of part T1 is more than or equal to the electricity of the first path terminal of the first switch unit
Pressure Ve1, so that the first switch element T1 turns off, power output end Vout and power input Vin
Disconnecting, now vehicle active antenna must be arrived supply voltage from power output end Vout, and realizes
The overcurrent protection of power supply 100.
It follows that the current foldback circuit 10 ' of the present embodiment offer and power supply 100, pass through
Second switch element T2, the second resistance R2, the 3rd resistance R3, the 4th resistance R4 and diode
D1 just can reliably control the break-make of the first switch element T1, thus realizes the function of overcurrent protection,
Simple in construction, additionally can be by arranging the second resistance R2 or regulation second electricity of different resistance values
The resistance value of resistance R2, obtains different size of current value, thus meets the mistake of different current needs
The function of stream protection, motility is high, low cost.
The above, be only preferred embodiment of the present utility model, not makees this utility model
Any pro forma restriction, although this utility model is disclosed above with preferred embodiment, but not
In order to limit utility model, any those skilled in the art, without departing from utility model technology
In aspects, when the technology contents of available the disclosure above makes a little change or is modified to equivalent change
The Equivalent embodiments changed, as long as being without departing from utility model technical scheme content, according to utility model
Any simple modification, equivalent variations and the modification that above example is made by technical spirit, all still falls within
In the range of technical solutions of the utility model.
Claims (6)
1. a current foldback circuit, it is characterised in that described circuit includes: the first switch element,
Second switch element, the first resistance, the second resistance, the 3rd resistance and diode；
Described first switch element includes that the first path terminal, alternate path end and first control end, described
First control end is via described first resistance eutral grounding, and described first controls end also via described 3rd resistance
Electrically connecting with described first path terminal, described first path terminal inputs with power supply via described second resistance
End electrical connection, described alternate path end electrically connects with power output end；
Described second switch element includes that third path end, fourth passage end and second control end, described
Second controls end electrically connects with described third path end via described second resistance, described third path end
Electrically connecting with described power input, described fourth passage end electrically connects with the anode of described diode,
The negative electrode of described diode controls end with described the first of described first switch element and electrically connects；
Wherein, the forward voltage drop of described diode is less than or equal to the electric conduction of described second switch element
Pressure.
2. current foldback circuit as claimed in claim 1, it is characterised in that described overcurrent protection electricity
Road also includes that the 4th resistance, the first end of described 4th resistance are controlled with the second of described second switch element
End processed electrically connects, and the second end of described 4th resistance is electric with the first path terminal of described first switch element
Connect.
3. current foldback circuit as claimed in claim 2, it is characterised in that described first switch unit
Part and described second switch element are PNP type triode.
4. a power supply, it is characterised in that described power supply includes such as claims 1 to 3
According to any one of current foldback circuit.
5. power supply as claimed in claim 4, it is characterised in that described power supply also includes
Control circuit, described control circuit includes: the 3rd switch element, the 5th resistance and the 6th resistance；
Described 3rd switch element includes that fifth passage end, clematis stem terminal and the 3rd control end, described
3rd controls end receives via described 5th resistance and enables signal, and described fifth passage end is via described the
Six resistance control end with the described 3rd and electrically connect, described fifth passage end ground connection, described clematis stem terminal
Control end via described first resistance with described the first of described first switch element to electrically connect.
6. power supply as claimed in claim 5, it is characterised in that described power supply also includes
Filter circuit, described filter circuit includes: the first inductance, the second inductance, the 3rd inductance and electric capacity；
First end of described first inductance electrically connects with described power input, the of described first inductance
Two ends electrically connect with the first end of described second inductance, the second end of described second inductance and described second
The described third path end electrical connection of switch element, the first end of described 3rd inductance and described first electricity
Second end electrical connection of sense, described second end of the 3rd inductance electrically connects with the first end of described electric capacity,
Second end ground connection of described electric capacity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620251694.0U CN205544195U (en) | 2016-03-28 | 2016-03-28 | Current foldback circuit and power supply |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620251694.0U CN205544195U (en) | 2016-03-28 | 2016-03-28 | Current foldback circuit and power supply |
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| Publication Number | Publication Date |
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| CN205544195U true CN205544195U (en) | 2016-08-31 |
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| CN201620251694.0U Active CN205544195U (en) | 2016-03-28 | 2016-03-28 | Current foldback circuit and power supply |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023174061A1 (en) * | 2022-03-17 | 2023-09-21 | 华为技术有限公司 | Apparatus for disconnecting circuit |
-
2016
- 2016-03-28 CN CN201620251694.0U patent/CN205544195U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023174061A1 (en) * | 2022-03-17 | 2023-09-21 | 华为技术有限公司 | Apparatus for disconnecting circuit |
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| GR01 | Patent grant |