CN204030562U - A kind of under-voltage protecting circuit of Switching Power Supply - Google Patents
A kind of under-voltage protecting circuit of Switching Power Supply Download PDFInfo
- Publication number
- CN204030562U CN204030562U CN201420437366.0U CN201420437366U CN204030562U CN 204030562 U CN204030562 U CN 204030562U CN 201420437366 U CN201420437366 U CN 201420437366U CN 204030562 U CN204030562 U CN 204030562U
- Authority
- CN
- China
- Prior art keywords
- semiconductor
- oxide
- power supply
- switching power
- metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Dc-Dc Converters (AREA)
- Protection Of Static Devices (AREA)
Abstract
The utility model relates to Switching Power Supply electronics applied technical field, especially a kind of under-voltage protecting circuit of Switching Power Supply.It is connected between externally fed unit and the main control chip of Switching Power Supply, comprises metal-oxide-semiconductor, the first resistance, the second resistance, the first electric capacity, the second electric capacity, Schottky diode and resistor group; The first resistance and the first electric capacity are parallel to respectively between the grid and source electrode of metal-oxide-semiconductor, zero line and live wire that the grid of metal-oxide-semiconductor is connected in externally fed unit by the Schottky diode of connecting successively and resistor group, between the output of Schottky diode and the source electrode of metal-oxide-semiconductor, be also connected with the second resistance, the source electrode of metal-oxide-semiconductor is also connected with live wire with the zero line of externally fed unit by the second electric capacity of series connection, the drain electrode of metal-oxide-semiconductor and source electrode respectively with corresponding connection of voltage input end of the main control chip of Switching Power Supply.The utility model is at input voltage during lower than preset value, and the main control chip of controllable switch power supply quits work, thereby realizes the protection to Switching Power Supply, has very strong practicality.
Description
Technical field
The utility model relates to Switching Power Supply electronics applied technical field, especially a kind of under-voltage protecting circuit of Switching Power Supply.
Background technology
Known, transformer and main control chip are the core building blocks of Switching Power Supply.At present, most of Switching Power Supplies on the market, when input voltage is too low, are still working on; Voltage step-down due to input, causes its transformer to change a lot, and easily produces magnetic saturation phenomenon, and then the problem ubiquity that Switching Power Supply is burnt.
Therefore, be necessary for the feature of Switching Power Supply itself, to provide a kind of protective circuit, the problem of easily being burnt effectively to reduce Switching Power Supply.
Utility model content
For above-mentioned the deficiencies in the prior art, the purpose of this utility model is to provide the under-voltage protecting circuit of simple, the safe and reliable Switching Power Supply of a kind of circuit structure.
To achieve these goals, the utility model adopts following technical scheme:
A kind of under-voltage protecting circuit of Switching Power Supply, it is connected between externally fed unit and the main control chip of Switching Power Supply, and it comprises metal-oxide-semiconductor, the first resistance, the second resistance, the first electric capacity, the second electric capacity, Schottky diode and the resistor group being in series by several the 3rd resistance;
Described the first resistance and the first electric capacity are parallel to respectively between the grid and source electrode of metal-oxide-semiconductor, zero line and live wire that the grid of described metal-oxide-semiconductor is connected in externally fed unit by the Schottky diode of connecting successively and resistor group, between the output of described Schottky diode and the source electrode of metal-oxide-semiconductor, be also connected with the second resistance, the source electrode of described metal-oxide-semiconductor is also connected with live wire with the zero line of externally fed unit by the second electric capacity of series connection, the drain electrode of described metal-oxide-semiconductor and source electrode respectively with corresponding connection of voltage input end of the main control chip of Switching Power Supply.
Preferably, between the drain electrode of described metal-oxide-semiconductor and source electrode, be also connected with parasitic diode.
Owing to having adopted such scheme, the utility model is at input voltage during lower than preset value, by metal-oxide-semiconductor, realize the power supply control to the main control chip of Switching Power Supply, make in time main control chip quit work, avoided occurring because of the transformer of Switching Power Supply the problem that magnetic saturation phenomenon causes Switching Power Supply to be burnt; It is simple in structure, safe and reliable, can effectively play the protective effect to Switching Power Supply, has very strong practicality.
Accompanying drawing explanation
Fig. 1 is the electrical block diagram of the utility model embodiment.
Embodiment
Below in conjunction with accompanying drawing, embodiment of the present utility model is elaborated, but the multitude of different ways that the utility model can be defined by the claims and cover is implemented.
As shown in Figure 1, the under-voltage protecting circuit of the Switching Power Supply of the present embodiment, it is connected between the main control chip 2 of externally fed unit 1 and Switching Power Supply, and it comprises metal-oxide-semiconductor Q1, the first resistance R 1, the second resistance R 2, the first capacitor C 1, the second capacitor C 2, Schottky diode ZD1 and the resistor group being in series by several the 3rd resistance R 3; Wherein, the first resistance R 1 and the first capacitor C 1 are parallel to respectively between the grid and source electrode of metal-oxide-semiconductor Q1, zero line N and live wire L that the grid of metal-oxide-semiconductor Q1 is connected in externally fed unit 1 by the Schottky diode ZD1 that connects successively and resistor group, between the source electrode of the output of Schottky diode ZD1 and metal-oxide-semiconductor Q1, be also connected with the second resistance R 2, the source electrode of metal-oxide-semiconductor Q1 is also connected with live wire L with the zero line N of externally fed unit 1 by the second capacitor C 2 of series connection, the drain electrode of metal-oxide-semiconductor Q1 and source electrode respectively with corresponding connection of voltage input end of the main control chip 2 of Switching Power Supply.So, utilize foregoing circuit structure, the voltage of inputting when externally fed unit 1 is during lower than the predeterminated voltage of metal-oxide-semiconductor Q1, metal-oxide-semiconductor Q1 turn-offs and exports high level to main control chip 2, main control chip 2 is quit work, and then the problem of the transformer of avoiding Switching Power Supply because occurring that magnetic saturation phenomenon is burnt; And the voltage of inputting when externally fed unit 1 is during higher than the predeterminated voltage of metal-oxide-semiconductor Q1, metal-oxide-semiconductor Q1 conducting to main control chip 2 output low levels, normally works main control chip 2.Meanwhile, utilize the characteristic of metal-oxide-semiconductor Q1, can make the value of minimum input voltage carry out as required free setting, to meet to greatest extent actual use needs.
In addition, for optimizing the circuit structure of whole protective circuit, can between the drain electrode of metal-oxide-semiconductor Q1 and source electrode, connect parasitic diode D1, to utilize parasitic diode D1 to improve turn-on and turn-off function and the effect of metal-oxide-semiconductor Q1.
The foregoing is only preferred embodiment of the present utility model; not thereby limit the scope of the claims of the present utility model; every equivalent structure or conversion of equivalent flow process that utilizes the utility model specification and accompanying drawing content to do; or be directly or indirectly used in other relevant technical fields, be all in like manner included in scope of patent protection of the present utility model.
Claims (2)
1. the under-voltage protecting circuit of a Switching Power Supply, it is characterized in that: it is connected between externally fed unit and the main control chip of Switching Power Supply, it comprises metal-oxide-semiconductor, the first resistance, the second resistance, the first electric capacity, the second electric capacity, Schottky diode and the resistor group being in series by several the 3rd resistance;
Described the first resistance and the first electric capacity are parallel to respectively between the grid and source electrode of metal-oxide-semiconductor, zero line and live wire that the grid of described metal-oxide-semiconductor is connected in externally fed unit by the Schottky diode of connecting successively and resistor group, between the output of described Schottky diode and the source electrode of metal-oxide-semiconductor, be also connected with the second resistance, the source electrode of described metal-oxide-semiconductor is also connected with live wire with the zero line of externally fed unit by the second electric capacity of series connection, the drain electrode of described metal-oxide-semiconductor and source electrode respectively with corresponding connection of voltage input end of the main control chip of Switching Power Supply.
2. the under-voltage protecting circuit of a kind of Switching Power Supply as claimed in claim 1, is characterized in that: between the drain electrode of described metal-oxide-semiconductor and source electrode, be also connected with parasitic diode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420437366.0U CN204030562U (en) | 2014-08-04 | 2014-08-04 | A kind of under-voltage protecting circuit of Switching Power Supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420437366.0U CN204030562U (en) | 2014-08-04 | 2014-08-04 | A kind of under-voltage protecting circuit of Switching Power Supply |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204030562U true CN204030562U (en) | 2014-12-17 |
Family
ID=52070391
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420437366.0U Expired - Fee Related CN204030562U (en) | 2014-08-04 | 2014-08-04 | A kind of under-voltage protecting circuit of Switching Power Supply |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204030562U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105406721A (en) * | 2015-12-18 | 2016-03-16 | 深圳市赢新光电发展有限公司 | Input under-voltage protection circuit and switching power supply |
-
2014
- 2014-08-04 CN CN201420437366.0U patent/CN204030562U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105406721A (en) * | 2015-12-18 | 2016-03-16 | 深圳市赢新光电发展有限公司 | Input under-voltage protection circuit and switching power supply |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN203313144U (en) | Backflow prevention circuit | |
| CN204361658U (en) | A kind of under-voltage protecting circuit | |
| CN203313043U (en) | Negative-voltage drive circuit of high-frequency MOSFET | |
| CN204257515U (en) | Control relay circuit | |
| CN203193500U (en) | Switching power supply and charging loop thereof | |
| CN204556715U (en) | A kind of zero cross detection circuit and convertible frequency air-conditioner | |
| CN204030562U (en) | A kind of under-voltage protecting circuit of Switching Power Supply | |
| CN203289074U (en) | Power supply direct-supply protection circuit and set-top box | |
| CN203086324U (en) | MOSFET driving and protecting circuit of miniwatt pulse transformer | |
| CN201937238U (en) | Input undervoltage protection circuit | |
| CN203800836U (en) | CS short circuit protection circuit for switch power supply | |
| CN204190358U (en) | A kind of LED power protective circuit turning off PWM chip and export | |
| CN203851319U (en) | Led drive circuit structure | |
| CN205566256U (en) | Alternating load isolation control circuit | |
| CN205142011U (en) | Teaching equipment standby power circuit | |
| CN205750611U (en) | A kind of regulator control circuit | |
| CN205545190U (en) | Circuit is got to single live wire | |
| CN204517360U (en) | Excess voltage protection | |
| CN204538964U (en) | A kind of Switching Power Supply of wide-voltage range | |
| CN205356134U (en) | Active absorption drive circuit and switching power supply | |
| CN203941495U (en) | A kind of off-line feed circuit for microprocessor chip | |
| CN203352552U (en) | Large current on-off control circuit | |
| CN204349851U (en) | Control of Fan Motor system | |
| CN204633621U (en) | A kind of Switching Power Supply underloading turns off the circuit of synchronous rectification | |
| CN104570816A (en) | Simple time delay power supply switching circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20141217 Termination date: 20190804 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |