CN204305431U - A kind of LED drive circuit - Google Patents
A kind of LED drive circuit Download PDFInfo
- Publication number
- CN204305431U CN204305431U CN201420847435.5U CN201420847435U CN204305431U CN 204305431 U CN204305431 U CN 204305431U CN 201420847435 U CN201420847435 U CN 201420847435U CN 204305431 U CN204305431 U CN 204305431U
- Authority
- CN
- China
- Prior art keywords
- circuit
- resistance
- led drive
- drive circuit
- triode
- 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.)
- Active
Links
Landscapes
- Circuit Arrangement For Electric Light Sources In General (AREA)
Abstract
The utility model provides a kind of LED drive circuit, relates to LED technology field.LED drive circuit comprises rectification circuit, buck circuit and control circuit of switch of audion, described buck circuit comprises transformer, the first diode, the first electric capacity and the first triode, described first electric capacity connects one end, former limit of described transformer, and the colelctor electrode of described first triode connects the positive pole of the former limit other end of described transformer, described first diode; Described control circuit of switch of audion comprises the first resistance and second electric capacity of series connection.The LED drive circuit that the utility model embodiment provides, first triode is as power stage circuit, by the control circuit of switch of audion of transformer, the first resistance, the second electric capacity composition, control the first triode batch (-type) conducting, compared with LED drive circuit of the prior art, cost is lower, and the volume of LED circuit can not be caused to increase.
Description
Technical field
The utility model relates to LED technology FIELD OF THE INVENTIONThe, in particular to a kind of LED drive circuit.
Background technology
Along with the extensive use of LED, LED actuation techniques is also day by day ripe.LED drive circuit is used for LED load output constant current, normally works in order to driving LED lamp.It mainly comprises power stage circuit and control circuit.Control circuit controls the master power switch pipe batch (-type) conducting in power stage circuit, thus makes power stage circuit convert the input voltage signal received to a constant current signal and export LED load to.Usually use FET as power stage circuit in current LED drive circuit, thus cause cost higher.
Utility model content
In view of this, the object of the utility model embodiment is to provide a kind of LED drive circuit, to reduce costs.
First aspect, the utility model embodiment provides a kind of LED drive circuit, comprises rectification circuit, buck circuit and control circuit of switch of audion, wherein,
Described buck circuit comprises transformer, the first diode, the first electric capacity and the first triode, described first electric capacity connects one end, former limit of described transformer, and the colelctor electrode of described first triode connects the positive pole of the former limit other end of described transformer, described first diode;
Described control circuit of switch of audion comprises the first resistance and second electric capacity of series connection, and described first resistance connects the secondary of described transformer, and described second electric capacity connects the base stage of described first triode.
In conjunction with first aspect, the utility model embodiment provides the first possible embodiment of first aspect, and described LED drive circuit also comprises current-limiting circuit.Current-limiting circuit is set, is unlikely to protect LED load to damage because electric current is excessive.
In conjunction with the first possible embodiment of first aspect, the utility model embodiment provides the possible embodiment of the second of first aspect, described current-limiting circuit comprises the second triode, 3rd triode, second resistance, 3rd resistance, 4th resistance, 5th resistance, 6th resistance, 7th resistance, 8th resistance and the second diode, the colelctor electrode of described second triode, the colelctor electrode of described 3rd triode all connects the base stage of described first triode, the emitter stage of described 3rd triode connects the base stage of described second triode, the emitter stage of described first triode is by described second resistance eutral grounding, described 5th resistance, 6th resistance, 7th resistance is connected successively, described 8th resistance and described second diodes in parallel.
In conjunction with the embodiment that the second of first aspect is possible, the utility model embodiment provides the third possible embodiment of first aspect, and wherein, described 7th resistance is thermistor.By the use of thermistor, to reach the current constant control under different temperatures.
In conjunction with first aspect, the utility model embodiment provides the 4th kind of possible embodiment of first aspect, and described LED drive circuit also comprises " π " type filter circuit, and described " π " type filter circuit comprises filter inductance and two filter capacitors.
In conjunction with first aspect, the utility model embodiment provides the 5th kind of possible embodiment of first aspect, and described LED drive circuit also comprises " L " type filter circuit, and described " L " type filter circuit comprises filter inductance and filter capacitor.By the setting of " π " type filter circuit or " L " type filter circuit, the direct current that rectification circuit is exported is cleaner.
In conjunction with the 5th kind of possible embodiment of first aspect; the utility model embodiment provides the 6th kind of possible embodiment of first aspect; described LED drive circuit also comprises overvoltage crowbar, and described overvoltage crowbar comprises the piezo-resistance in parallel with described filter capacitor.By the setting of overvoltage crowbar, avoid output voltage excessive and damage LED load.
In conjunction with first aspect, the utility model embodiment provides the 7th kind of possible embodiment of first aspect, and the input of described rectification circuit is connected with fuse-link.Fuse-link, also known as fuse, is damaged because of catastrophic failure by the components and parts arranged in protection LED drive circuit of fuse-link.
In conjunction with first aspect; the utility model embodiment provides the 8th kind of possible embodiment of first aspect; described LED drive circuit also comprises short-circuit protection circuit; described short-circuit protection circuit comprises the 9th resistance, and described 9th resistor coupled in parallel is in the load voltage output of described LED drive circuit.By arranging short-circuit protection circuit, protection LED load is unlikely to damage because of short circuit or open fault.
The LED drive circuit that the utility model embodiment provides, first triode is as power stage circuit, by the control circuit of switch of audion of transformer, the first resistance, the second electric capacity composition, control the first triode batch (-type) conducting, compared with LED drive circuit of the prior art, cost is lower, and the volume of LED circuit can not be caused to increase.
For making above-mentioned purpose of the present utility model, feature and advantage become apparent, preferred embodiment cited below particularly, and coordinate appended accompanying drawing, be described in detail below.
Accompanying drawing explanation
In order to be illustrated more clearly in the technical scheme of the utility model embodiment, be briefly described to the accompanying drawing used required in embodiment below, be to be understood that, the following drawings illustrate only some embodiment of the present utility model, therefore the restriction to scope should be counted as, for those of ordinary skill in the art, under the prerequisite not paying creative work, other relevant accompanying drawings can also be obtained according to these accompanying drawings.
Fig. 1 shows a kind of LED drive circuit that the utility model embodiment one provides;
Fig. 2 shows a kind of LED drive circuit that the utility model embodiment two provides.
Main element symbol description:
101-rectification circuit, 102-" L " type filter circuit, 103-overvoltage crowbar, 104-buck circuit, 105-current-limiting circuit, 106-control circuit of switch of audion.
Detailed description of the invention
Below in conjunction with accompanying drawing in the utility model embodiment, be clearly and completely described the technical scheme in the utility model embodiment, obviously, described embodiment is only the utility model part embodiment, instead of whole embodiments.The assembly of the utility model embodiment describing and illustrate in usual accompanying drawing herein can be arranged with various different configuration and design.Therefore, below to the detailed description of the embodiment of the present utility model provided in the accompanying drawings and the claimed scope of the present utility model of not intended to be limiting, but selected embodiment of the present utility model is only represented.Based on embodiment of the present utility model, the every other embodiment that those skilled in the art obtain under the prerequisite not making creative work, all belongs to the scope of the utility model protection.
Because current LED drive circuit uses FET as power stage circuit usually, and the cost of FET is higher, thus causes the cost of LED drive circuit higher.In view of this, inventor, through constantly research, proposes the LED drive circuit that the utility model embodiment provides.This LED drive circuit adopts triode as power stage circuit, by controlling the conducting of triode batch (-type) primarily of the control circuit of switch of audion of the components and parts compositions such as resistance, electric capacity and transformer, realizes LED load drived control.The cost of triode is far below FET, and the control circuit of switch of audion of first device composition such as resistance, electric capacity and transformer is carried little, not only reduce the cost of LED drive circuit, also ensure the small form factor requirements of LED drive circuit, adapt to LED technology towards low cost, miniaturization demand.
With specific embodiment, the LED drive circuit that the utility model embodiment provides is described in detail below.
Fig. 1 shows a kind of LED drive circuit that the utility model embodiment one provides.Consult Fig. 1, the LED drive circuit that the utility model embodiment one provides comprises rectification circuit 101, buck circuit 104 (also known as BUCK circuit) and control circuit of switch of audion 106, wherein,
Described buck circuit 104 comprises transformer T1, the first diode D1, the first electric capacity C0 and the first triode Q1, described first electric capacity C0 connects one end, former limit of described transformer T1, and the colelctor electrode of described first triode Q1 connects the positive pole of the former limit other end of described transformer T1, described first diode D1;
Described control circuit of switch of audion 106 comprises the first resistance R5 and the second electric capacity C2 of series connection, and described first resistance R5 connects the secondary of described transformer T1, and described second electric capacity C2 connects the base stage of described first triode Q1.
The input of rectification circuit 101 connects interchange input, and output connects the first electric capacity C0, and interchange input rectifying is converted to direct current and exports by rectification circuit 101.During the first triode Q1 conducting, electric current flows through the former limit of transformer T1, flows through load LED lamp pearl, then gets back to power cathode by the first triode Q1 and the second resistance R0.When first triode Q1 turns off, electric current flows through the former limit of transformer T1, load LED lamp pearl, the first diode D1 form loop.
The LED drive circuit that the utility model embodiment provides, by the first triode Q1 as power stage circuit, compared to existing LED drive circuit, cost is lower, and the switch of the first triode Q1 is controlled by the first resistance R5 and the second electric capacity C2, structure is simple, the volume of LED drive circuit can not be caused to increase, meet the requirement of people to LED drive circuit small size, low cost.
Preferably, circuit damage LED load excessive in circuit, described LED drive circuit also comprises current-limiting circuit 105.Current-limiting circuit 105 can have multiple implementation.As a kind of embodiment, as shown in Figure 1, described current-limiting circuit 105 can comprise the second triode Q2, the 3rd triode Q3, the second resistance R0, the 3rd resistance R1, the 4th resistance R2, the 5th resistance R3, the 6th resistance R4, the 7th resistance RC, the 8th resistance R7 and the second diode D2.The colelctor electrode of described second triode Q2, the colelctor electrode of described 3rd triode Q3 all connect the base stage of described first triode Q1, the emitter stage of described 3rd triode Q3 connects the base stage of described second triode Q2, the grounded emitter of the second triode Q2, the base stage of the 3rd triode Q3 connects the 5th resistance R3.The emitter stage of described first triode Q1 is by described second resistance R0 ground connection.The secondary of the 3rd resistance R1 connection transformer T1, described 5th resistance R3, the 6th resistance R4, the 7th resistance RC connect successively, the 7th resistance RC ground connection.4th resistance R2 is connected with the 3rd resistance R1, and is connected to the emitter stage of the first triode Q1.Described 8th resistance R7 is in parallel with described second diode D2, and is connected to the colelctor electrode of described second triode Q2.
Preferably, the 7th resistance RC is thermistor, to realize the current constant control under different temperatures.
The power supply of LED drive circuit is generally civil power, and civil power exists the situation of tripping operation suddenly unavoidably, and current break is easy to the component damage caused in circuit.Preferably, the input of described rectification circuit is connected with fuse-link FUSE1 (fuse), and the components and parts in protection LED drive circuit do not damage because of catastrophic failure.
Common, exchange in the direct current inputting and obtain after over commutation and may there is interference, the direct current obtained to make rectification is cleaner, and LED drive circuit also comprises filter circuit.Filter circuit can adopt " π " type filter circuit, and described " π " type filter circuit comprises filter inductance and two filter capacitors.As another kind of embodiment, filter circuit also can adopt " L " type filter circuit 102, and described " L " type filter circuit 102 comprises filter inductance L1 and filter capacitor C1.
If in circuit, voltage is excessive also can damage LED load; be unlikely to protect LED load to damage because voltage is excessive; preferably; described LED drive circuit also comprises overvoltage crowbar 103, and described overvoltage crowbar 103 comprises the piezo-resistance VR1 in parallel with described filter capacitor C1.Avoid output voltage excessive by piezo-resistance VR1 and damage LED load.
Fig. 2 shows the structure of the LED drive circuit that the utility model embodiment two provides, and the basis of the LED drive circuit that the LED drive circuit that the present embodiment provides provides in the utility model embodiment one is further improved.Consult Fig. 2; compared with the LED drive circuit that the LED drive circuit that the present embodiment provides and the utility model embodiment one provide; the main distinction is; described LED drive circuit also comprises short-circuit protection circuit; described short-circuit protection circuit comprises the 9th resistance R8; 9th resistance R8 is parallel to the load voltage output of LED drive circuit, and the load of protection LED is avoided damaging because of open circuit or short trouble.
The above; be only detailed description of the invention of the present utility model; but protection domain of the present utility model is not limited thereto; anyly be familiar with those skilled in the art in the technical scope that the utility model discloses; change can be expected easily or replace, all should be encompassed within protection domain of the present utility model.Therefore, protection domain of the present utility model should described be as the criterion with the protection domain of claim.
Claims (9)
1. a LED drive circuit, is characterized in that, comprises rectification circuit, buck circuit and control circuit of switch of audion, wherein,
Described buck circuit comprises transformer, the first diode, the first electric capacity and the first triode, described first electric capacity connects one end, former limit of described transformer, and the colelctor electrode of described first triode connects the positive pole of the former limit other end of described transformer, described first diode respectively;
Described control circuit of switch of audion comprises the first resistance and second electric capacity of series connection, and described first resistance connects the secondary of described transformer, and described second electric capacity connects the base stage of described first triode.
2. LED drive circuit according to claim 1, is characterized in that, described LED drive circuit also comprises current-limiting circuit.
3. LED drive circuit according to claim 2, it is characterized in that, described current-limiting circuit comprises the second triode, 3rd triode, second resistance, 3rd resistance, 4th resistance, 5th resistance, 6th resistance, 7th resistance, 8th resistance and the second diode, the colelctor electrode of described second triode, the colelctor electrode of described 3rd triode all connects the base stage of described first triode, the emitter stage of described 3rd triode connects the base stage of described second triode, the emitter stage of described first triode is by described second resistance eutral grounding, described 5th resistance, 6th resistance, 7th resistance is connected successively, described 8th resistance and described second diodes in parallel.
4. LED drive circuit according to claim 3, is characterized in that, described 7th resistance is thermistor.
5. LED drive circuit according to claim 1, is characterized in that, described LED drive circuit also comprises " π " type filter circuit, and described " π " type filter circuit comprises filter inductance and two filter capacitors.
6. LED drive circuit according to claim 1, is characterized in that, described LED drive circuit also comprises " L " type filter circuit, and described " L " type filter circuit comprises filter inductance and filter capacitor.
7. LED drive circuit according to claim 6, is characterized in that, described LED drive circuit also comprises overvoltage crowbar, and described overvoltage crowbar comprises the piezo-resistance in parallel with described filter capacitor.
8. LED drive circuit according to claim 1, is characterized in that, the input of described rectification circuit is connected with fuse-link.
9. LED drive circuit according to claim 1, is characterized in that, described LED drive circuit also comprises short-circuit protection circuit, and described short-circuit protection circuit comprises the 9th resistance, and described 9th resistor coupled in parallel is in the load voltage output of described LED drive circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420847435.5U CN204305431U (en) | 2014-12-25 | 2014-12-25 | A kind of LED drive circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420847435.5U CN204305431U (en) | 2014-12-25 | 2014-12-25 | A kind of LED drive circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204305431U true CN204305431U (en) | 2015-04-29 |
Family
ID=53110932
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420847435.5U Active CN204305431U (en) | 2014-12-25 | 2014-12-25 | A kind of LED drive circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204305431U (en) |
-
2014
- 2014-12-25 CN CN201420847435.5U patent/CN204305431U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN206321697U (en) | Overvoltage detection circuit and switching power supply circuit | |
| CN204361658U (en) | Undervoltage protection circuit | |
| CN103022978B (en) | For the over under-voltage protection circuit of multiple pulse rectification circuit | |
| CN103474965A (en) | Low-cost alternating-current input overvoltage protection circuit and switching power supply | |
| CN203537225U (en) | Novel antisurge constant-current switching power supply | |
| CN106034369A (en) | LED power supply with short-circuit protection circuit | |
| CN108879629A (en) | A kind of lithium battery charger output anti-surge circuit | |
| CN104682338B (en) | A kind of protection circuit and lighting apparatus | |
| CN206804838U (en) | Wireless battery logging | |
| CN203398768U (en) | Low-cost AC input overvoltage protection circuit and switching power supply | |
| CN203368003U (en) | Dual protection device for Boost circuit | |
| CN106887904A (en) | A kind of wireless electric energy transmission device with overvoltage protection | |
| CN202351726U (en) | Resistance and capacitance step-down control circuit | |
| CN104953863A (en) | Switching power circuit for power supply of three-phase electric energy meter | |
| CN103475191A (en) | Control circuit of switching power supply | |
| CN104216449B (en) | A kind of controllability alternating current steady voltage plug | |
| CN204305431U (en) | A kind of LED drive circuit | |
| CN207426665U (en) | Current transformer and its secondary side protective arrangement for limiting output voltage | |
| CN213991098U (en) | LED drive circuit with protection function | |
| CN204681075U (en) | Power-down protection circuit | |
| CN209805697U (en) | Single live wire power supply circuit | |
| CN109618467B (en) | Linear LED load matching circuit under double voltages | |
| CN207117157U (en) | A kind of overvoltage crowbar for computer radiating fan | |
| CN203056540U (en) | Auxiliary output protective circuit for Set Top Box circuit board | |
| CN101577492B (en) | Power supply circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |