CN205584024U - Take switching power supply circuit of excess temperature protection - Google Patents

Take switching power supply circuit of excess temperature protection Download PDF

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Publication number
CN205584024U
CN205584024U CN201620100409.5U CN201620100409U CN205584024U CN 205584024 U CN205584024 U CN 205584024U CN 201620100409 U CN201620100409 U CN 201620100409U CN 205584024 U CN205584024 U CN 205584024U
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CN
China
Prior art keywords
switching power
power supply
series arm
critesistor
divider resistance
Prior art date
Application number
CN201620100409.5U
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Chinese (zh)
Inventor
谭曙光
王俊洋
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广州视源电子科技股份有限公司
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Priority to CN201620100409.5U priority Critical patent/CN205584024U/en
Application granted granted Critical
Publication of CN205584024U publication Critical patent/CN205584024U/en

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Abstract

The utility model discloses a take switching power supply circuit of excess temperature protection, include: power module, power control module, sampling resistor and the series branch of constituteing by divider resistance and thermistor, connect the series branch between sampling resistor and power module's major loop output, gather divider resistance and the output voltage of the public node of thermistor and the current signal of the sampling resistor of flowing through, power control module basis output voltage with output that the current signal comes the regulating switch power to be in order reducing generating heat of switching power supply, or reaches in the switching power supply temperature and close switching power supply in limited time. The utility model discloses can be under the prerequisite that does not increase the circuit cost, adopt dual detection 's mode, the more effective switching power supply of preventing can not normally work because of the excess temperature damages.

Description

A kind of switching power circuit of band overheat protector
Technical field
This utility model relates to field of switch power, particularly relates to the switching power circuit of a kind of band overheat protector.
Background technology
Thermal-shutdown circuit for the temperature of testing circuit or equipment reach to make during a threshold value protection act with Prevent circuit and equipment from damaging cisco unity malfunction because of excess temperature.
Most existing Switching Power Supplies use a conventional, electric-resistance and a critesistor composition series arm, are formed Resitstance voltage divider, detects Switching Power Supply by gathering the voltage at conventional, electric-resistance and critesistor common node Temperature.But prior art Shortcomings, when humid environment or Switching Power Supply break down, it may appear that Leaky so that the voltage of voltage acquisition point can be clamped to certain magnitude of voltage, this magnitude of voltage may be electricity Source control module is judged as normal magnitude of voltage, and in the case, energy supply control module will be considered to circuit temperature Normally, will not export excess temperature control signal, overheat protector lost efficacy.The existing Switching Power Supply of minority uses dual inspection The scheme surveyed realizes overvoltage protection, as arranged two temperature sensing circuits, when a temperature sensing circuit loses During effect, another one temperature protection circuit can also normally work, but realize this scheme and need more components and parts, Circuit cost is high.
Utility model content
Technical problem to be solved in the utility model is, it is provided that the switch power supply of a kind of band overheat protector Road, on the premise of not increasing circuit cost, can use the mode of double check, more effectively prevent switch Power supply damages cisco unity malfunction because of excess temperature.
In order to solve above-mentioned technical problem, the utility model proposes the switch power supply of a kind of band overheat protector Road, including: power module, energy supply control module, sampling resistor and be made up of with critesistor divider resistance Series arm;
Described power module has power input, controlled end, major loop outfan and for connecting load Power output end;Described energy supply control module has the first test side, the second test side and output control terminal;
The major loop outfan of described power module connects the first end of described sampling resistor;Described sampling resistor The first end be also connected with the first test side of described energy supply control module and the second end of described series arm, institute State the second end ground connection of sampling resistor;The first of described series arm terminates into DC power signal, described string In connection branch road, divider resistance is connected the second detection of described energy supply control module with the common node of critesistor End;The output control terminal of described energy supply control module connects the controlled end of described power module.
Preferably, first end that the first end is described series arm of divider resistance, institute in described series arm The second end stating divider resistance connects the first end of described critesistor, and the second end of described critesistor is institute State the second end of series arm.
Preferably, first end that the first end is described series arm of critesistor, institute in described series arm The second end stating critesistor connects the first end of described divider resistance, and the second end of described divider resistance is institute State the second end of series arm.
Further, the first of described series arm terminates into DC power signal particularly as follows: described series connection is propped up It is the power supply of Vcc that first end on road connects magnitude of voltage.
Further, described critesistor is negative tempperature coefficient thermistor.
Further, described power module includes switching tube;Described switching tube be power field effect transistor or Insulated gate bipolar transistor;
The grid of described switching tube is the controlled end of described power module, and described source electrode is described power module Major loop outfan.
Further, described critesistor is positioned at an adjacent domain of described switching tube.
Further, described energy supply control module is PDM keyer.
Implement this utility model, have the advantages that
The switching power circuit of the band overheat protector that this utility model provides, will be by divider resistance and critesistor The series arm of composition is connected between the sampling resistor of Switching Power Supply and the major loop outfan of power module, adopts Collect the output voltage signal at divider resistance and critesistor common node and flow through the electric current letter of sampling resistor Number, energy supply control module regulates the defeated of Switching Power Supply according to described output voltage signal and described current signal Go out the power heating with minimizing Switching Power Supply, or the closing switch power supply when Switching Power Supply temperature reaches the upper limit. When output voltage signal at divider resistance with critesistor common node cannot reflect variations in temperature, permissible Reflect variations in temperature by flowing through sampling resistor electric current, and described sampling resistor is existing Switching Power Supply Central Plains Have for detect output electric current device, therefore this utility model can on the premise of not increasing circuit cost, Use the mode of double check, more effectively prevent Switching Power Supply from damaging cisco unity malfunction because of excess temperature.
Accompanying drawing explanation
The structure of one embodiment of the switching power circuit of the band overheat protector that Fig. 1 provides for this utility model Schematic diagram;
The knot of another embodiment of the switching power circuit of the band overheat protector that Fig. 2 provides for this utility model Structure schematic diagram.
Detailed description of the invention
Below in conjunction with the accompanying drawing in this utility model embodiment, to the technical side in this utility model embodiment Case is clearly and completely described, it is clear that described embodiment is only that this utility model part is real Execute example rather than whole embodiments.Based on the embodiment in this utility model, ordinary skill people The every other embodiment that member is obtained under not making creative work premise, broadly falls into this utility model The scope of protection.
Existing Switching Power Supply structure includes sampling resistor, and described sampling resistor is for gathering the defeated of Switching Power Supply Go out current signal, i.e. in existing Switching Power Supply, flow through the output that electric current the is Switching Power Supply electricity of sampling resistor Stream, the change of the electric current that energy supply control module flows through sampling resistor by detection detects Switching Power Supply output electricity The change of stream, and then carry out the defeated of stable switch power supply by the on or off controlling Switching Power Supply breaker in middle pipe Go out.
See Fig. 1, be an enforcement of the switching power circuit of a kind of band overheat protector that this utility model provides The structural representation of example.
The switching power circuit of the band overheat protector in the present embodiment, including: power module 1, power supply control mould Block 2, sampling resistor Rs and by divider resistance R1 and critesistor RNTCThe series arm 3 of composition;
Described power module 1 has power input Vin, controlled end, major loop outfan and negative for connecting The power output end Vout carried;Described energy supply control module 2 has the first test side, the second test side and defeated Go out to control end;
The major loop outfan of described power module 1 connects first end of described sampling resistor Rs;Described sampling First end of resistance Rs is also connected with the first test side of described energy supply control module and the of described series arm 3 Two ends, the second end ground connection of described sampling resistor Rs;The first of described series arm 3 terminates into DC source Signal, divider resistance R1 and critesistor R in described series arm 3NTCCommon node connect described electricity Second test side of source control module;The output control terminal of described energy supply control module connects described power module 1 Controlled end.
Further, in described series arm 3, first end of divider resistance R1 is the of described series arm 3 One end, second end of described divider resistance R1 connects described critesistor RNTCThe first end, described temperature-sensitive Resistance RNTCThe second end that the second end is described series arm 3.
It should be noted that the power input Vin of power module 1 accesses Switching Power Supply input power signal, Input power signal is alternating voltage or d. c. voltage signal.Power module 1 include transition filter circuit, Input rectifying filter circuit, switching tube, main transformer and output rectifier and filter, transition filter circuit master Being used for suppressing the spike in civil power transition, input rectifying filter circuit is for the output of transition filter circuit Voltage signal carries out rectification and filtering, and the primary side of main transformer is connected with the drain electrode of switching tube, secondary side with Output rectifier and filter is connected, it is provided that the low-voltage direct output of power supply;Energy supply control module 2 is used for Output situation according to power module 1 controls the on or off of switching tube, thus stable switch power supply Output signal, in being embodied as, it is possible to use single-chip microcomputer output pwm control signal realizes;Sampling electricity The current signal that resistance Rs collects is the electric current in series arm 3 and power module 1 output current signal sum; In the present embodiment, the critesistor R in series arm 3NTCFor detecting main power device in Switching Power Supply The temperature of (such as switching tube), divider resistance R1 can be that single resistance can also be for multiple resistant series or also The resistor network that joint group becomes, divider resistance R1 and critesistor RNTCCommon node at output voltage with Variations in temperature and change, when Switching Power Supply temperature raises, divider resistance R1 and critesistor RNTCPublic affairs Output voltage at conode reduces.
The operation principle of the switching power circuit of the band overheat protector that the present embodiment provides is as follows:
The temperature of Switching Power Supply raises, critesistor RNTCTemperature raise, critesistor RNTCResistance subtract Little, divider resistance R1 and critesistor RNTCCommon node at output voltage reduce, power supply control mould The output control terminal output pwm control signal of block 2, controls Switching Power Supply and reduces output, Switching Power Supply Heating reduces.When the temperature of Switching Power Supply reaches ceiling temperature, i.e. divider resistance R1 and critesistor RNTC Common node at output voltage less than threshold value time, energy supply control module 2 control Switching Power Supply close.
Meanwhile, the temperature of Switching Power Supply raises, critesistor RNTCTemperature raise, critesistor RNTC Resistance reduce, electric current in series arm 3 increases so that the electric current flowing through sampling resistor Rs increases, electricity Source control module 2 detects that the electric current flowing through sampling resistor Rs increases, and exports PWM by control output end Control signal so that the output electric current of Switching Power Supply reduces, output reduces, and Switching Power Supply heating reduces. Visible, in the present embodiment, the curent change flowing through sampling resistor Rs is possible not only to reflect energy supply control module The change of the output electric current of 2, it is also possible to the variations in temperature of reflection Switching Power Supply.
Therefore, energy supply control module 2 can be simultaneously by detection divider resistance R1 and critesistor RNTCPublic Output voltage signal at conode and flow through the current signal of sampling resistor Rs to detect the change of temperature, when Divider resistance R1 and critesistor RNTCWhen output voltage signal at common node cannot reflect variations in temperature, Variations in temperature can be reflected, it is achieved that the function of double check by flowing through sampling resistor Rs electric current;And Described sampling resistor Rs is that therefore the present embodiment is for detecting the device of output electric current in existing Switching Power Supply Make use of an existing sampling resistor Rs to realize double check, it is not necessary to additionally to increase cost.
See Fig. 2, be another reality of the switching power circuit of a kind of band overheat protector that this utility model provides Execute the structural representation of example.
Unlike embodiment illustrated in fig. 1, in the present embodiment, critesistor in described series arm 3 RNTCThe first end that the first end is described series arm 3, described critesistor RNTCSecond end connect institute Stating first end of divider resistance R1, second end of described divider resistance R1 is the second of described series arm 3 End.
Further, the first of described series arm 3 terminates into DC power signal particularly as follows: described series connection It is the power supply of Vcc that first end of branch road 3 connects magnitude of voltage.
Further, described critesistor RNTCFor negative tempperature coefficient thermistor RNTC
Further, described power module 1 includes switching tube;Described switching tube is power field effect transistor Or insulated gate bipolar transistor;
The grid of described switching tube is the controlled end of described power module 1, and described source electrode is described power module 1 Major loop outfan.
Further, described critesistor RNTCIt is positioned at an adjacent domain of described switching tube.
Further, described energy supply control module 2 is PDM keyer.
It should be noted that the current signal that sampling resistor Rs collects is the electric current in series arm 3 and electricity Source module 1 output current signal sum;In the present embodiment, the critesistor R in series arm 3NTCWith The temperature of main power device (such as switching tube) in detection Switching Power Supply, divider resistance R1 can be single electricity Resistance can also be for multiple resistant series or the resistor network composed in parallel, divider resistance R1 and critesistor RNTC Common node at output voltage vary with temperature and change, when Switching Power Supply temperature raises, dividing potential drop electricity Resistance R1 and critesistor RNTCCommon node at output voltage increase.
It addition, Vcc is+15V in the present embodiment.
The operation principle of the switching power circuit of the band overheat protector that the present embodiment provides is as follows:
The temperature of Switching Power Supply raises, critesistor RNTCTemperature raise, critesistor RNTCResistance subtract Little, divider resistance R1 and critesistor RNTCCommon node at output voltage increase, power supply control mould The output control terminal output pwm control signal of block 2, controls Switching Power Supply and reduces output, Switching Power Supply Heating reduces.When the temperature of Switching Power Supply reaches ceiling temperature, i.e. divider resistance R1 and critesistor RNTC Common node at output voltage higher than threshold value time, energy supply control module 2 control Switching Power Supply close.
Meanwhile, the temperature of Switching Power Supply raises, critesistor RNTCTemperature raise, critesistor RNTC Resistance reduce, electric current in series arm 3 increases so that the electric current flowing through sampling resistor Rs increases, electricity Source control module 2 detects that the electric current flowing through sampling resistor Rs increases, and exports PWM by control output end Control signal so that the output electric current of Switching Power Supply reduces, output reduces, and Switching Power Supply heating reduces.
Compared to prior art, the useful effect of the switching power circuit of a kind of band overheat protector of the present utility model Fruit is:
The switching power circuit of the band overheat protector that this utility model provides, will be by divider resistance and critesistor The series arm of composition is connected between the sampling resistor of Switching Power Supply and the major loop outfan of power module, adopts Collect the output voltage signal at divider resistance and critesistor common node and flow through the electric current letter of sampling resistor Number, energy supply control module regulates the defeated of Switching Power Supply according to described output voltage signal and described current signal Go out the power heating with minimizing Switching Power Supply, or the closing switch power supply when Switching Power Supply temperature reaches the upper limit. When output voltage signal at divider resistance with critesistor common node cannot reflect variations in temperature, permissible Reflect variations in temperature by flowing through sampling resistor electric current, and described sampling resistor is existing Switching Power Supply Central Plains Have for detect output electric current device, therefore this utility model can on the premise of not increasing circuit cost, Use the mode of double check, more effectively prevent Switching Power Supply from damaging cisco unity malfunction because of excess temperature.
The above is preferred implementation of the present utility model, it is noted that general for the art For logical technical staff, on the premise of without departing from this utility model principle, it is also possible to make some improvement and Deformation, these improve and deformation is also considered as protection domain of the present utility model.

Claims (8)

1. the switching power circuit of a band overheat protector, it is characterised in that including: power module, energy supply control module, sampling resistor and the series arm being made up of divider resistance and critesistor;
Described power module has power input, controlled end, major loop outfan and for connecting the power output end of load;Described energy supply control module has the first test side, the second test side and output control terminal;
The major loop outfan of described power module connects the first end of described sampling resistor;First end of described sampling resistor is also connected with the first test side of described energy supply control module and the second end of described series arm, the second end ground connection of described sampling resistor;The first of described series arm terminates into DC power signal, and in described series arm, divider resistance is connected the second test side of described energy supply control module with the common node of critesistor;The output control terminal of described energy supply control module connects the controlled end of described power module.
2. the switching power circuit of band overheat protector as claimed in claim 1; it is characterized in that; first end that first end is described series arm of divider resistance in described series arm; second end of described divider resistance connects the first end of described critesistor, second end that the second end is described series arm of described critesistor.
3. the switching power circuit of band overheat protector as claimed in claim 1; it is characterized in that; first end that first end is described series arm of critesistor in described series arm; second end of described critesistor connects the first end of described divider resistance, second end that the second end is described series arm of described divider resistance.
4. the switching power circuit of band overheat protector as claimed in claim 1, it is characterised in that the first of described series arm terminates into DC power signal particularly as follows: it is the power supply of Vcc that the first end of described series arm connects magnitude of voltage.
5. the switching power circuit of band overheat protector as claimed in claim 1, it is characterised in that described critesistor is negative tempperature coefficient thermistor.
6. the switching power circuit of the band overheat protector as described in any one of Claims 1 to 5, it is characterised in that described power module includes switching tube;Described switching tube is power field effect transistor or insulated gate bipolar transistor;
The grid of described switching tube is the controlled end of described power module, and the source electrode of described switching tube is the major loop outfan of described power module.
7. the switching power circuit of band overheat protector as claimed in claim 6, it is characterised in that described critesistor is positioned at an adjacent domain of described switching tube.
8. the switching power circuit of band overheat protector as claimed in claim 1, it is characterised in that described energy supply control module is PDM keyer.
CN201620100409.5U 2016-02-01 2016-02-01 Take switching power supply circuit of excess temperature protection CN205584024U (en)

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108507696A (en) * 2017-02-28 2018-09-07 株式会社村田制作所 Temperature measuring equipment
CN108572689A (en) * 2017-03-10 2018-09-25 台达电子企业管理(上海)有限公司 Switching Power Supply, excess temperature control guard method and Poewr control method
CN108879603A (en) * 2018-07-23 2018-11-23 南京通华芯微电子有限公司 The implementation method of temperature detection in a kind of temperature protection circuit
CN109217258A (en) * 2018-10-24 2019-01-15 广州金升阳科技有限公司 A kind of control circuit
CN111509961A (en) * 2020-05-18 2020-08-07 广东美的暖通设备有限公司 Over-temperature protection device, variable frequency driver, electrical appliance, method, device and storage medium

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108507696A (en) * 2017-02-28 2018-09-07 株式会社村田制作所 Temperature measuring equipment
CN108572689A (en) * 2017-03-10 2018-09-25 台达电子企业管理(上海)有限公司 Switching Power Supply, excess temperature control guard method and Poewr control method
US10886725B2 (en) 2017-03-10 2021-01-05 Delta Electronics (Shanghai) Co., Ltd Switching power supply, over-temperature control and protection method, and power control method
CN108879603A (en) * 2018-07-23 2018-11-23 南京通华芯微电子有限公司 The implementation method of temperature detection in a kind of temperature protection circuit
CN109217258A (en) * 2018-10-24 2019-01-15 广州金升阳科技有限公司 A kind of control circuit
CN111509961A (en) * 2020-05-18 2020-08-07 广东美的暖通设备有限公司 Over-temperature protection device, variable frequency driver, electrical appliance, method, device and storage medium

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