CN203884030U - LED switching power source adopting primary side control technology - Google Patents
LED switching power source adopting primary side control technology Download PDFInfo
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- CN203884030U CN203884030U CN201420139355.4U CN201420139355U CN203884030U CN 203884030 U CN203884030 U CN 203884030U CN 201420139355 U CN201420139355 U CN 201420139355U CN 203884030 U CN203884030 U CN 203884030U
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Abstract
The utility model belongs to the technical field of switching power sources and relates to an LED switching power source adopting primary side control technology. The LED switching power source comprises a rectifying and filtering circuit, a switch transformer, an MOS tube VT, an auxiliary winding, a rectifying diode VD5, a filtering capacitor C3 and a chip OB2532. The LED switching power source has the advantages of simpler structure and effectively reduced cost.
Description
Technical field
The utility model relates to switch power technology field, relates in particular to a kind of LED Switching Power Supply of applying former limit control technology.
Background technology
LED, as novel energy-conserving light source, has the features such as light efficiency is high, environmental protection, life-span length.LED needs the driving power of constant current output while using, LED driving power is that power supply supply is converted to specific electric current and voltage with the luminous power supply changeover device of driving LED, generally, the input of LED driving power comprises high pressure industrial frequency AC (being civil power), low-voltage direct, high voltage direct current, low pressure high-frequency ac etc.LED driving power belongs to Switching Power Supply, and the quality and reliability of Switching Power Supply depends on its circuit design, production technology, and the quality of device, and meanwhile, LED driving power directly affects the useful life of LED.Mostly adopt at present output constant current feedback system, sort circuit carries out current sample from output, by amplifier, carries out signal amplification, and utilizes light-coupled isolation feedback.This circuit has feedback circuit complexity, the shortcoming that cost is relatively high.
Summary of the invention
The purpose of this utility model is to provide a kind of LED Switching Power Supply of applying former limit control technology for the deficiencies in the prior art, and its circuit structure is simpler, can effectively reduce costs.
For achieving the above object, the utility model adopts following technical scheme: a kind of LED Switching Power Supply of applying former limit control technology, and it comprises current rectifying and wave filtering circuit, switch transformer, metal-oxide-semiconductor VT, auxiliary winding, rectifier diode VD5, filter capacitor C3 and chip OB2532; The input of described current rectifying and wave filtering circuit connects alternating voltage AC, the armature winding N1 of the output connecting valve transformer of current rectifying and wave filtering circuit, the secondary winding N2 of switch transformer is connected with rectifier diode VD1 and capacitor C 2, and rectifier diode VD1 is parallel with resistance R 3 and capacitor C 7; Described armature winding N1 connects metal-oxide-semiconductor VT and leaks level, and the source electrode that the GND pin of the grid connection chip OB2532 of metal-oxide-semiconductor VT meets metal-oxide-semiconductor VT connects the current detecting input pin CS of chip OB2532 and one end of sampling resistor R5, the other end ground connection of sampling resistor R5; The output of current rectifying and wave filtering circuit connects the VDD pin of chip OB2532 successively after contact resistance R1, R2; Auxiliary winding connects the positive pole of rectifier diode VD5, and the negative pole of rectifier diode VD5 connects the positive pole of filter capacitor C3 and the VDD pin of chip OB2532, the minus earth of filter capacitor C3; The negative pole of rectifier diode VD5 is also connected with resistance R 4 and R6 in turn, and chip OB2532 end of oppisite phase INV is connected between resistance R 4 and R6, resistance R 6 ground connection.
The input of described current rectifying and wave filtering circuit is connected with fuse.
The input of described current rectifying and wave filtering circuit is connected with thermistor.
The utility model beneficial effect is: a kind of LED Switching Power Supply of applying former limit control technology of the utility model, it comprises current rectifying and wave filtering circuit, switch transformer, metal-oxide-semiconductor VT, auxiliary winding, rectifier diode VD5, filter capacitor C3 and chip OB2532, there is circuit structure simpler, the advantage effectively reducing costs.
Accompanying drawing explanation
Accompanying drawing 1 is circuit theory diagrams of the present utility model.
Embodiment
Below in conjunction with accompanying drawing, the utility model is further described: as shown in Figure 1, a kind of LED Switching Power Supply of applying former limit control technology described in the utility model, it comprises current rectifying and wave filtering circuit, switch transformer, metal-oxide-semiconductor VT, auxiliary winding, rectifier diode VD5, filter capacitor C3 and chip OB2532; The input of described current rectifying and wave filtering circuit connects alternating voltage AC, the armature winding N1 of the output connecting valve transformer of current rectifying and wave filtering circuit, the secondary winding N2 of switch transformer is connected with rectifier diode VD1 and capacitor C 2, and rectifier diode VD1 is parallel with resistance R 3 and capacitor C 7; Described armature winding N1 connects metal-oxide-semiconductor VT and leaks level, and the grid of metal-oxide-semiconductor VT connects the GND pin of chip OB2532, and the source electrode of metal-oxide-semiconductor VT connects the current detecting input pin CS of chip OB2532 and one end of sampling resistor R5, the other end ground connection of sampling resistor R5; The output of current rectifying and wave filtering circuit connects the VDD pin of chip OB2532 successively after contact resistance R1, R2, for connecting chip OB2532, provides starting current; Auxiliary winding connects the positive pole of rectifier diode VD5, and the negative pole of rectifier diode VD5 connects the positive pole of filter capacitor C3 and the VDD pin of chip OB2532, the minus earth of filter capacitor C3; The negative pole of rectifier diode VD5 is also connected with resistance R 4 and R6 in turn, and chip OB2532 end of oppisite phase INV is connected between resistance R 4 and R6, resistance R 6 ground connection.Because rectifier diode VD5 is in the on off state of high frequency when the circuit working, resistance R 3 and capacitor C 7 produce vibration with avoiding rectifier diode VD5.Preferably, the input of described current rectifying and wave filtering circuit is connected with fuse.Preferably, the input of described current rectifying and wave filtering circuit is connected with thermistor, thermistor can prevent that surge current from causing damage to device below, and when power supply is not also switched on, the resistance of thermistor is very large, so can play the effect of limit inrush currents, after the normal work of circuit, thermistor, owing to there being electric current to pass through to generate heat, causes resistance can become very little, so after normal work, the power loss of thermistor is very little.
220 V alternating voltage AC of input, after current rectifying and wave filtering circuit, become the armature winding N1 that direct voltage is added to switch transformer, then the drain electrode of receiving metal-oxide-semiconductor VT.Auxiliary winding N2 is for chip OB2532 provides power supply after rectifier diode VD5, filter capacitor C3, and auxiliary winding N2 and resistance R 4, R6 are also for the end of oppisite phase INV of chip OB2532 provides sampling feedback voltage simultaneously.The current signal that the resistance R 5 of connection metal-oxide-semiconductor VT source electrode obtains detection is added on the current detecting input pin CS of chip OB2532.Under the control of INV end feedback voltage signal and CS current signal, the pulse duration of the gate drive signal of metal-oxide-semiconductor VT is adjusted, make power supply and electric current keep constant.The advantage of this circuit is former limit FEEDBACK CONTROL, need not add optocoupler and source of stable pressure, has reduced cost, has circuit structure simpler, the advantage effectively reducing costs.
The above is only better embodiment of the present utility model, and the equivalence of doing according to structure, feature and principle described in the utility model patent claim therefore all changes or modifies, and is included in the utility model patent claim.
Claims (3)
1. a LED Switching Power Supply for the former limit of application control technology, is characterized in that: it comprises current rectifying and wave filtering circuit, switch transformer, metal-oxide-semiconductor VT, auxiliary winding, rectifier diode VD5, filter capacitor C3 and chip OB2532; The input of described current rectifying and wave filtering circuit connects alternating voltage AC, the armature winding N1 of the output connecting valve transformer of current rectifying and wave filtering circuit, the secondary winding N2 of switch transformer is connected with rectifier diode VD1 and capacitor C 2, and rectifier diode VD1 is parallel with resistance R 3 and capacitor C 7; Described armature winding N1 connects metal-oxide-semiconductor VT and leaks level, and the grid of metal-oxide-semiconductor VT connects the GND pin of chip OB2532, and the source electrode of metal-oxide-semiconductor VT connects the current detecting input pin CS of chip OB2532 and one end of sampling resistor R5, the other end ground connection of sampling resistor R5; The output of current rectifying and wave filtering circuit connects the VDD pin of chip OB2532 successively after contact resistance R1, R2; Auxiliary winding connects the positive pole of rectifier diode VD5, and the negative pole of rectifier diode VD5 connects the positive pole of filter capacitor C3 and the VDD pin of chip OB2532, the minus earth of filter capacitor C3; The negative pole of rectifier diode VD5 is also connected with resistance R 4 and R6 in turn, and chip OB2532 end of oppisite phase INV is connected between resistance R 4 and R6, resistance R 6 ground connection.
2. a kind of LED Switching Power Supply of applying former limit control technology according to claim 1, is characterized in that: the input of described current rectifying and wave filtering circuit is connected with fuse.
3. a kind of LED Switching Power Supply of applying former limit control technology according to claim 1, is characterized in that: the input of described current rectifying and wave filtering circuit is connected with thermistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420139355.4U CN203884030U (en) | 2014-03-26 | 2014-03-26 | LED switching power source adopting primary side control technology |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420139355.4U CN203884030U (en) | 2014-03-26 | 2014-03-26 | LED switching power source adopting primary side control technology |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203884030U true CN203884030U (en) | 2014-10-15 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420139355.4U Expired - Fee Related CN203884030U (en) | 2014-03-26 | 2014-03-26 | LED switching power source adopting primary side control technology |
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| Country | Link |
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| CN (1) | CN203884030U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111142041A (en) * | 2020-01-10 | 2020-05-12 | 上海力信电气技术有限公司 | Power supply testing device |
-
2014
- 2014-03-26 CN CN201420139355.4U patent/CN203884030U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111142041A (en) * | 2020-01-10 | 2020-05-12 | 上海力信电气技术有限公司 | Power supply testing device |
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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: 20141015 Termination date: 20150326 |
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| EXPY | Termination of patent right or utility model |