CN1630155A - Power supply protective device and electronic device with protective device - Google Patents
Power supply protective device and electronic device with protective device Download PDFInfo
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- CN1630155A CN1630155A CN 200310122370 CN200310122370A CN1630155A CN 1630155 A CN1630155 A CN 1630155A CN 200310122370 CN200310122370 CN 200310122370 CN 200310122370 A CN200310122370 A CN 200310122370A CN 1630155 A CN1630155 A CN 1630155A
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- power supply
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Abstract
This invention provides a power supply protector, which contains an overload protective circuit coupling connected to switch circuit and power supply for driving switch circuit to make current limiting operation to limit the output current of power supply increment, a short circuit protective circuit coupling connected to output end of switch circuit for switching off the switch circuit to cutting off power supply when short circuit occurring in output end.
Description
Technical field
The present invention is relevant for a kind of apparatus for protecting power supply, particularly relevant for a kind of a kind of apparatus for protecting power supply that utilizes switching circuit, overload protecting circuit and short-circuit protection circuit to protect electronic installation.
Background technology
The simplest current limiting element is a fuse, and it can use separately or be used with other protection component, because fuse can prevent the impact of overcurrent effectively, they are necessary in system, also is the final defence line of system when running into bust.
What the protection component of the external power supply of electronic product at present was commonly used has two kinds, and first kind is common fuse, and the protection that its shortcoming can only be done once for this element is operated; After blowout, then must change, therefore; If this element is used for electronic product, the chance that then can cause electronic product to send the maintenance of former factory back to increases.
Another kind is self-resetting type fuse (poly switch), and its advantage is to take place also can continue to use after the protection operation, and its shortcoming is when the protection operation takes place, and this element can produce high hot.Fig. 1 represents the temperature and the current characteristics figure of known self-resetting type fuse, and A is that the characteristic curve of model nanoSMD, microSMD or miniSMD, characteristic curve and the C that B is model miniSMDE190 are the characteristic curve of model SMDH160; As shown in Figure 1, the protective current of self-resetting type fuse (poly switch) can descend with temperature on every side and raise, and makes the voltage power supply scope be subjected to the restriction of temperature; But self-resetting type fuse (polyswitch) can repeatedly use and need not change, and this is the great advantage with respect to the standard fuse.
The operation principle of self-resetting type fuse is, comes protective circuit to avoid infringement via heightening self-resistance under overcurrent condition, in case that electric current recovers is normal, the self-resetting type fuse can automatically restore to normal low resistance.The ideal that these characteristics make the self-resetting type fuse become power supply power supply and data communication application is selected, and immediate current may occur because these are applied in when changing battery or hot-swap data connection.The self-resetting type fuse replaces traditional plate glass insurance silk usually in some circuit, and is mainly used in the USB application.
These two kinds of fuses all must be realized defencive function via the heat that overcurrent in the sensor circuit produces, and the general insurance silk comes interruptive current via fusing, and the self-resetting type fuse then limits electric current via low-resistance is changed into high resistant.
Because at present general insurance silk and self-resetting type fuse be in being seen everywhere on the market, yet for its shortcoming good settling mode is not arranged, therefore; The invention provides a kind of preferable solution, better temperature characterisitic is arranged, also need not change, thereby carry out the current limliting operation and stop out-put supply than self-resetting type fuse; Therefore be quite suitable settling mode if replace general insurance silk and self-resetting type fuse with the present invention.
Summary of the invention
In view of this, main purpose of the present invention is for providing a kind of apparatus for protecting power supply, particularly relevant for a kind of a kind of apparatus for protecting power supply that utilizes switching circuit, overload protecting circuit and short-circuit protection circuit to protect electronic installation.
For achieving the above object, the present invention proposes a kind of apparatus for protecting power supply, comprises a switching circuit; One overload protecting circuit and a short-circuit protection circuit.
The input of switching circuit couples a power supply, and exports this power supply by output; When the electric current of exporting when power supply arrived one first electric current, then the driving switch circuit carried out the current limliting operation, and the electric current that power supply is exported no longer increases; When the output of switching circuit is short-circuited, then switching circuit is turn-offed, to stop to export this power supply.Be able to protective device with this and be not damaged, and make system's energy steady operation.
For above-mentioned purpose of the present invention, feature and advantage can be become apparent, some preferred embodiments cited below particularly, and conjunction with figs. are described in detail as follows.
Description of drawings
Fig. 1 represents the temperature and the current characteristics figure of known self-resetting type fuse;
Fig. 2 represents the calcspar of first embodiment of the present invention apparatus for protecting power supply;
Fig. 3 represents the circuit diagram of second embodiment of the present invention apparatus for protecting power supply;
Fig. 4 represents that the third embodiment of the present invention has the calcspar of the electronic installation of protective device.
Symbol description
10: overload protecting circuit, 102: detecting unit, 104: the first protected locations; 20: switching circuit, 202: switching transistor, 204: biasing circuit; 30: short-circuit protection circuit, 302: short-circuit detecting unit, 304: the second protected locations; 40: internal circuit; 50: power supply, 60: display unit, 70: apparatus for protecting power supply; 80: electronic installation, V
Out: out-put supply, R
1: starting resistance, D
1: Schottky diode (schottkydiode), Q
1: the first transistor, Q
2: transistor seconds, Q
3: the 3rd transistor, R
1: first biasing resistor, R
2: second biasing resistor, R
3: the 3rd biasing resistor, S
1: first control signal, S
2: second control signal, L
1: status signal, V
1: overload signal, V
2: short-circuit signal, I
1: electric current.
Embodiment
Embodiment one:
Fig. 2 represents the calcspar of first embodiment of the present invention apparatus for protecting power supply.As shown in Figure 2, a switching circuit 20 comprises a switching transistor 202 and a biasing circuit 204, and its input couples a power supply 50, and output is in order to out-put supply V
OutOne overload protecting circuit 10 is coupled between switching circuit 20 and the power supply 50; comprise a detecting unit 102 and one first protected location 104; other has a short-circuit protection circuit 30 to couple the output of switching circuit 20, comprises a short-circuit detecting unit 302 and one second protected location 304.
The operation principle of apparatus for protecting power supply of the present invention is as follows.Overload protecting circuit 10 comprises the detecting unit 102 and first protected location 104; its detecting unit 102 is serially connected with between the input utmost point and power supply 50 of switching transistor 202; in order to detect the electric current that power supply 50 is exported, when this electric current arrives one first electric current, then export an overload signal V
1And first protected location 104 couples the output of detecting unit 102, when first protected location 104 receives overload signal V
1The time, then export one first control signal S
1This first control signal S
1The biasing of the control switch transistor 202 control utmost points is carried out the electric current that the current limliting operation is exported with control power supply 50 in order to driving switch transistor 202 via biasing circuit 204, and this electric current is limited in the safe range.
Short-circuit protection circuit 30 comprises the short-circuit detecting unit 302 and second protected location 304, and its short-circuit detecting unit 302 couples the output of switching circuit 20, when the output of switching circuit 20 is short-circuited, then exports a short-circuit signal V
2And second protected location 304 is coupled between short-circuit detecting unit 302 and the switching circuit 20, when second protected location 304 receives short-circuit signal V
2The time, then export one second control signal S
2This second control signal S
2Can change the biasing that biasing circuit 204 is provided, and then stopcock transistor 202, to stop out-put supply V
Out, reach the operation of power protection.
Embodiment two:
Fig. 3 represents the circuit diagram of second embodiment of the present invention apparatus for protecting power supply.The operation principle of present embodiment is with shown in above-mentioned first embodiment, in addition; Use a starting resistance R
1As detecting unit 102, a first transistor Q
1As first protected location 104, a transistor seconds Q
2As switching transistor 202, one the 3rd transistor Q
3As second protected location 304, a Schottky diode (schottky diode) D
1As short-circuit detecting unit 302 and one first biasing resistor R
1, one second biasing resistor R
2With one the 3rd biasing resistor R
3As biasing circuit 204.
As shown in Figure 3, starting resistance R
1Be serially connected with transistor seconds Q
2Emitter-base bandgap grading and power supply 50 between, as starting resistance R
1On the electric current I that flow through
1Arrive one first electric current, and make electric current I
1With starting resistance R
1Product when equaling a specific voltage, for example 0.6 volt, at this moment; Starting resistance R
1Export an overload signal V
1(0.6 volt) makes the first transistor Q
1Conducting.As the first transistor Q
1Receive this overload signal V
1When (0.6 volt), then by the first transistor Q
1Collector electrode export one first control signal S
1This first control signal S
1Via the first biasing resistor R
1And control transistor seconds Q
2The biasing of base stage is in order to drive transistor seconds Q
2Carry out the current limliting operation and control the electric current that power supply 50 is exported, this electric current is limited in the safe range.
Schottky diode D
1Be coupled in transistor seconds Q
2Collector electrode and the 3rd transistor Q
3Base stage between, as out-put supply V
OutWhen being short-circuited, Schottky diode D
1Can output one short-circuit signal V
2(for example 0.2 volt) is to the 3rd transistor Q
3Base stage, this short-circuit signal V
2(0.2 volt) can impel the 3rd transistor Q
3Enter cut-off region, and by the 3rd transistor Q
3Collector electrode export one second control signal S
2, this second control signal S
2Via the second biasing resistor R
2And the biasing of control biasing circuit 204, and then turn-off transistor seconds Q
2To stop out-put supply V
Out, reach the operation of power protection.
Embodiment three:
Fig. 4 represents that the third embodiment of the present invention has the calcspar of the electronic installation of protective device.The operation principle of present embodiment is with shown in above-mentioned first embodiment, in addition; Difference is in an apparatus for protecting power supply 70 is arranged in the electronic installation 80, and in order to supplying an internal circuit 40 required power supply, and this electronic installation 80 also comprises a display unit 60, in addition; Second protected location, 304 more exportable status signal L
3In order to the operation of control display unit 60, make display unit 60 be able to the operation of 20 normal runnings of display switch circuit, current limliting or stop the state of out-put supply.
In sum, the present invention has following advantage:
When system or equipment be short-circuited or the situation of overcurrent under, but except protection system or equipment were impaired, apparatus for protecting power supply also can continue to use and must not change, and than general insurance silk better economic benefit is arranged.
2. than self-resetting type fuse better temperature characterisitic is arranged, make system that better operating efficiency can be arranged.
In sum, though the present invention with preferred embodiment openly as above, right its is not in order to limit the present invention, any those skilled in the art, under the situation that does not break away from the spirit and scope of the present invention, can carry out various changes and modification, therefore scope of the present invention is as the criterion with the claim restricted portion that is proposed.
Claims (18)
1. apparatus for protecting power supply comprises:
One switching circuit, its input couples a power supply, and exports this power supply by its output;
One overload protecting circuit couples between this switching circuit and this power supply, when the electric current of exporting when this power supply arrives one first electric current, then drives this switching circuit and carries out the current limliting operation, and the electric current that this power supply is exported no longer increases;
One short-circuit protection circuit couples the output of this switching circuit, when the output of this switching circuit is short-circuited, then this switching circuit is turn-offed, to stop to export this power supply.
2. apparatus for protecting power supply as claimed in claim 1, wherein, this overload protecting circuit comprises:
One detecting unit in order to detect the electric current of this power supply output, when this electric current arrives this first electric current, is then exported an overload signal;
One first protected location couples the output of this detecting unit, when receiving this overload signal, then exports one first control signal and carries out above-mentioned current limliting operation to drive this switching circuit.
3. apparatus for protecting power supply as claimed in claim 2, wherein, this detecting unit is a starting resistance, is serially connected with between this switching circuit and this power supply; This first protected location is a transistor, the conducting owing to the biasing of this overload signal, and export this first control signal.
4. apparatus for protecting power supply as claimed in claim 2, wherein, this switching circuit comprises: a switching transistor, its input utmost point couples this power supply; And a biasing circuit, be coupled between the control utmost point of this power supply and this switching transistor, in order to being provided, biasing makes this switching transistor conducting, so that can export this power supply by the output stage of this switching transistor.
5. apparatus for protecting power supply as claimed in claim 4, wherein, the control utmost point of this switching transistor couples the output of this first protected location.
6. apparatus for protecting power supply as claimed in claim 1, wherein, this short-circuit protection circuit comprises:
One short-circuit detecting unit couples the output of this switching circuit, when the output of this switching circuit is short-circuited, then exports a short-circuit signal;
One second protected location couples the output of this short-circuit detecting unit, when receiving this short-circuit signal, then exports one second control signal to turn-off this switching circuit.
7. apparatus for protecting power supply as claimed in claim 6, wherein, this switching circuit comprises: a switching transistor, its input utmost point couples this power supply; And a biasing circuit, be coupled between the control utmost point of this power supply and this switching transistor, in order to being provided, biasing makes this switching transistor conducting, so that can export this power supply by the output stage of this switching transistor.
8. apparatus for protecting power supply as claimed in claim 7, wherein, the control utmost point of this switching transistor couples the output of this second protected location, and this second control signal changes the biasing that this biasing circuit provides, and turn-offs this switching transistor.
9. apparatus for protecting power supply as claimed in claim 6, wherein, this short-circuit detecting unit is a Schottky diode.
10. electronic installation with protective device comprises:
One power supply;
One internal circuit;
One switching circuit, its input couples this power supply, and exports this power supply to this internal circuit by its output;
One overload protecting circuit couples between this switching circuit and this power supply, when the electric current of exporting when this power supply arrives one first electric current, then drives this switching circuit and carries out the current limliting operation, and the electric current that this power supply is exported no longer increases;
One short-circuit protection circuit couples the output of this switching circuit, and when this internal circuit was short-circuited, the output end voltage of this switching circuit changed, and this switching circuit was turn-offed, to stop to export this power supply.
11. the electronic installation with protective device as claimed in claim 10, wherein, this electronic installation comprises:
One detecting unit in order to detect the electric current of this power supply output, when this electric current arrives this first electric current, is then exported an overload signal;
One first protected location couples the output of this detecting unit, when receiving this overload signal, then exports one first control signal and carries out above-mentioned current limliting operation to drive this switching circuit.
12. the electronic installation with protective device as claimed in claim 11, wherein, this detecting unit is a starting resistance, is serially connected with between this switching circuit and this power supply; This first protected location is a transistor, owing to the work of this overload signal is pressed and conducting, and exports this first control signal.
13. the electronic installation with protective device as claimed in claim 11, wherein, this switching circuit comprises: a switching transistor, and its input utmost point couples this power supply; And a biasing circuit, be coupled between the control utmost point of this power supply and this switching transistor, in order to being provided, biasing makes this switching transistor conducting, so that can export this power supply by the output stage of this switching transistor.
14. the electronic installation with protective device as claimed in claim 13, wherein, the control utmost point of this switching transistor couples the output of this first protected location.
15. the electronic installation with protective device as claimed in claim 10, wherein, this short-circuit protection circuit comprises:
One short-circuit detecting unit couples the output of this switching circuit, when the output of this switching circuit is short-circuited, then exports a short-circuit signal;
One second protected location couples the output of this short-circuit detecting unit, when receiving this short-circuit signal, then exports one second control signal to turn-off this switching circuit.
16. the electronic installation with protective device as claimed in claim 15, wherein, this switching circuit comprises: a switching transistor, and its input utmost point couples this power supply; And a biasing circuit, be coupled between the control utmost point of this power supply and this switching transistor, in order to being provided, biasing makes this switching transistor conducting, so that can export this power supply by the output stage of this switching transistor.
17. the electronic installation with protective device as claimed in claim 16, wherein, the control utmost point of this switching transistor couples the output of this second protected location, and this second control signal changes the biasing that this biasing circuit provides, and turn-offs this switching transistor.
18. the electronic installation with protective device as claimed in claim 15, wherein, this short-circuit detecting unit is a Schottky diode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200310122370 CN1630155A (en) | 2003-12-19 | 2003-12-19 | Power supply protective device and electronic device with protective device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200310122370 CN1630155A (en) | 2003-12-19 | 2003-12-19 | Power supply protective device and electronic device with protective device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1630155A true CN1630155A (en) | 2005-06-22 |
Family
ID=34844483
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200310122370 Pending CN1630155A (en) | 2003-12-19 | 2003-12-19 | Power supply protective device and electronic device with protective device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1630155A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101986492A (en) * | 2010-11-08 | 2011-03-16 | 中兴通讯股份有限公司 | Short-circuit protection circuit and short-circuit protection method |
| CN102013658A (en) * | 2009-09-08 | 2011-04-13 | 鸿富锦精密工业（深圳）有限公司 | Over-current protection circuit |
| CN102035165A (en) * | 2009-09-29 | 2011-04-27 | 意法半导体研发（上海）有限公司 | System and method for providing short-circuit protection |
| CN101626299B (en) * | 2009-08-04 | 2012-03-07 | 北京星网锐捷网络技术有限公司 | Stackable switch, switch stacking system and cable hot plugging method |
| CN105745724A (en) * | 2013-12-10 | 2016-07-06 | 施耐德电器工业公司 | Short-circuiting device of an electrical installation and system for extinguishing an electrical arc that may appear in such an installation |
| CN115882421A (en) * | 2023-02-23 | 2023-03-31 | 杰华特微电子股份有限公司 | Electronic fuse circuit and circuit system applying same |
-
2003
- 2003-12-19 CN CN 200310122370 patent/CN1630155A/en active Pending
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101626299B (en) * | 2009-08-04 | 2012-03-07 | 北京星网锐捷网络技术有限公司 | Stackable switch, switch stacking system and cable hot plugging method |
| CN102013658A (en) * | 2009-09-08 | 2011-04-13 | 鸿富锦精密工业（深圳）有限公司 | Over-current protection circuit |
| CN102013658B (en) * | 2009-09-08 | 2014-10-08 | 鸿富锦精密工业（深圳）有限公司 | Over-current protection circuit |
| CN102035165A (en) * | 2009-09-29 | 2011-04-27 | 意法半导体研发（上海）有限公司 | System and method for providing short-circuit protection |
| CN102035165B (en) * | 2009-09-29 | 2014-07-30 | 意法半导体研发（上海）有限公司 | System and method for providing short-circuit protection |
| CN101986492A (en) * | 2010-11-08 | 2011-03-16 | 中兴通讯股份有限公司 | Short-circuit protection circuit and short-circuit protection method |
| CN101986492B (en) * | 2010-11-08 | 2015-01-28 | 中兴通讯股份有限公司 | Short-circuit protection circuit and short-circuit protection method |
| CN105745724A (en) * | 2013-12-10 | 2016-07-06 | 施耐德电器工业公司 | Short-circuiting device of an electrical installation and system for extinguishing an electrical arc that may appear in such an installation |
| CN105745724B (en) * | 2013-12-10 | 2019-07-12 | 施耐德电器工业公司 | The short-circuit device of electric device and system for eliminating the electric arc in device |
| CN115882421A (en) * | 2023-02-23 | 2023-03-31 | 杰华特微电子股份有限公司 | Electronic fuse circuit and circuit system applying same |
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| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |