CN203368835U - LED drive circuit - Google Patents
LED drive circuit Download PDFInfo
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- CN203368835U CN203368835U CN 201320359451 CN201320359451U CN203368835U CN 203368835 U CN203368835 U CN 203368835U CN 201320359451 CN201320359451 CN 201320359451 CN 201320359451 U CN201320359451 U CN 201320359451U CN 203368835 U CN203368835 U CN 203368835U
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Abstract
The utility model relates to an LED drive circuit. A protective circuit comprises a triode Q2. A collector electrode of the triode Q2 is connected with a grid electrode of a field effect transistor Q1. A base electrode of the triode Q2 is connected with a source electrode of the field effect transistor Q1. An emitting electrode of the triode Q2 is grounded. The protective circuit comprises a resistor R12, a capacitor C12 and a thyristor VT. An anode of the thyristor VT is connected with a drive output end of a drive chip U1. A cathode of the thyristor VT is grounded. A gate pole of the thyristor VT is connected with one end of the resistor R12 and one end of the capacitor C12. The other end of the resistor R12 is grounded, and the other end of the capacitor C12 is connected with the source electrode of the field effect transistor Q1. After the breakdown of the field effect transistor Q1, the triode Q2 is rapidly saturated, the collector electrode of the triode Q2 is short-circuited to ground, thus the drive chip U1 is protected; the high voltage generated on the upper end of a current-limiting resistor R15 passes through the capacitor C12 to be applied to the gate pole of the thyristor VT, so that the thyristor VT is conducted, the anode voltage of the thyristor VT drops to 0 V, and the drive chip U1 is protected. By adopting the LED drive circuit, the drive chip U1 is effectively protected, and multi-protection is realized.
Description
Technical field
The utility model relates to a kind of power circuit, specifically, relates to a kind of LED drive circuit of the LED of being applicable to lighting lamp power, belongs to electronic technology field.
Background technology
At present, traditional LED illuminating lamp driving circuit comprises power circuit 1, output circuit 2, voltage stabilizing circuit 3, amplifying circuit 4, sample circuit 5, Drive and Control Circuit 6 and PFC correcting circuit 8, as shown in Figure 1, Drive and Control Circuit 6 comprises driving chip U1, field effect transistor Q1, drive 7 pin of chip U1, be that drive output connects the grid of field effect transistor Q1 through the diode D11 of reversal connection, the source electrode of field effect transistor Q1 is through resistance R 15 ground connection, diode D11 is parallel with resistance R 13, the grid of field effect transistor Q1 is through resistance R 14 ground connection, the drain electrode of field effect transistor Q1 connects the positive pole of diode D6, an end of the first primary coil in switch transformer T, the negative pole of diode D6 is through resistance R in parallel 2, capacitor C 5 connects the other end and the power supply of switch transformer T primary coil.
In realizing the utility model process, utility model people finds in prior art at least to exist following problem: because field effect transistor Q1 is consumable accessory, punch through damage easily occurs, when being on the scene effect pipe Q1 punctures, the high pressure of field effect transistor Q1 drain electrode directly is added to grid, and is added to through resistance R 13, diode D11 the drive output that drives chip U1, makes to drive chip U1 to damage, poor stability, improved use cost.
The utility model content
The technical problems to be solved in the utility model is for above deficiency, and a kind of safe, LED drive circuit that use cost is low is provided.
For solving above technical problem, the utility model is by the following technical solutions: a kind of LED drive circuit, comprise Drive and Control Circuit, Drive and Control Circuit comprises driving chip U1 and field effect transistor Q1, the grid that the drive output of driving chip U1 meets field effect transistor Q1 through the diode D11 of reversal connection, it is characterized in that: described Drive and Control Circuit is electrically connected with protective circuit;
Described protective circuit comprises triode Q2, and the collector electrode of triode Q2 connects the grid of field effect transistor Q1;
The base stage of triode Q2 connects the source electrode of field effect transistor Q1, the grounded emitter of triode Q2.
A kind of prioritization scheme, described protective circuit comprises resistance R 12, capacitor C 12 and thyristor VT;
The anode of described thyristor VT connects the drive output that drives chip U1, the minus earth of thyristor VT;
The end of the gate pole connecting resistance R12 of described thyristor VT and an end of capacitor C 12;
The other end ground connection of described resistance R 12, the source electrode of another termination field effect transistor Q1 of capacitor C 12.
Another kind of prioritization scheme, described protective circuit comprises voltage-stabiliser tube ZD1 and voltage-stabiliser tube ZD2;
The negative pole of described voltage-stabiliser tube ZD1 connects the drive output that drives chip U1, the plus earth of voltage-stabiliser tube ZD1;
The negative pole of described voltage-stabiliser tube ZD2 connects the positive pole of diode D11, the plus earth of voltage-stabiliser tube ZD2.
Another prioritization scheme, described protective circuit comprises fast disconnected protective tube FU;
Described fast disconnected protective tube FU is arranged between the collector electrode of the negative pole of voltage-stabiliser tube ZD2 and triode Q2.
Further prioritization scheme, 4 pin of described driving chip U1 connect the source electrode of field effect transistor Q1.
Prioritization scheme further, described Drive and Control Circuit also comprises resistance R 14 and current-limiting resistance R15;
The source electrode of described field effect transistor Q1 is through current-limiting resistance R15 ground connection, and resistance R 14 is connected between the source electrode of the grid of field effect transistor Q1 and field effect transistor Q1.
Prioritization scheme further, described LED drive circuit also comprises power circuit, voltage stabilizing circuit, amplifying circuit and the sample circuit of electrical connection;
Described Drive and Control Circuit also comprises driving chip U1, resistance R 7, resistance R 24, capacitor C 10, diode D10, resistance R 13, resistance R 14 and current-limiting resistance R15;
The end of the 1 pin connecting resistance R7 of described driving chip U1, an end of resistance R 24, an end of capacitor C 10, another termination of the other end of resistance R 24, capacitor C 10 drives 2 pin of chip U1 and the output of amplifying circuit.
Further, the input of another termination amplifying circuit of described resistance R 7, positive pole and the sample circuit of diode D10, the negative pole of diode D10 accesses the sample circuit and drives 8 pin of chip U1;
5 pin of described driving chip U1 connect power circuit through resistance R 6, drive the 6 pin ground of chip U1, and resistance R 13 is in parallel with diode D11,
The drain electrode of described field effect transistor Q1 connects power circuit, drives 8 pin of chip U1 to connect power circuit through resistance R 5.
Again further, described power circuit comprises rectifier bridge, diode D5, diode D6, resistance R 1, resistance R 2, capacitor C 3, capacitor C 4, capacitor C 5 and switch transformer T;
Described transformer T has the first primary coil, the second primary coil and secondary coil, and capacitor C 3 is connected between the positive pole and ground of rectifier bridge;
The positive pole of one termination rectifier bridge of described resistance R 1,8 pin of an end of another termination capacitor C 4 of resistance R 1, the negative pole of diode D5 and driving chip U1, the other end ground connection of capacitor C 4;
The positive pole of described diode D5 connects an end of the first primary coil, 5 pin of driving chip U1, the other end ground connection of the first primary coil.
Further, the positive pole of an end of described capacitor C 5, a termination rectifier bridge of resistance R 2, the negative pole of another terminating diode D6 of the other end of capacitor C 5, resistance R 2;
The positive pole of one termination rectifier bridge of described the second primary coil, the positive pole of another terminating diode D6 of the second primary coil, the drain electrode of field effect transistor Q1, capacitor C 5, resistance R 2 and diode D6 form surge absorbing circuit.
After the utility model adopts above technical scheme, compared with prior art, have the following advantages: after field effect transistor Q1 punctures, have large electric current and flow through current-limiting resistance R15, produce high voltage in current-limiting resistance R15 upper end, this high voltage can be added to the base stage of triode Q2, make triode Q2 saturated rapidly, the collector electrode of triode Q2 is shorted to ground, and the gate short of field effect transistor Q1, to ground, makes high voltage can not be added to the drive output that drives chip U1.Thereby protection drives chip U1.The high voltage that current-limiting resistance R15 upper end produces is added to the gate pole of thyristor VT simultaneously by capacitor C 12, make its conducting, and the anode voltage of thyristor VT is reduced to 0V, makes to drive chip U1 to be protected.Voltage-stabiliser tube ZD1, voltage-stabiliser tube ZD2: when the grid of field effect transistor Q1 has high voltage to occur, voltage-stabiliser tube ZD1, voltage-stabiliser tube ZD2 puncture, and make to drive chip U1 to be protected.When the grid voltage of field effect transistor Q1 is too high; have large electric current and flow through voltage-stabiliser tube ZD1, voltage-stabiliser tube ZD2 and thyristor VT, quick-break fuse FU quick-break, make to drive chip U1 and high voltage thoroughly to be isolated; protection drives chip U1 effectively, has realized multiple protective.
Below in conjunction with drawings and Examples, the utility model is elaborated.
The accompanying drawing explanation
In figure,
The 1-power circuit, 2-output circuit, 3-voltage stabilizing circuit, 4-amplifying circuit, 5-sample circuit, 6-Drive and Control Circuit, 7-protective circuit, 8-PFC correcting circuit, 9-LED illuminating lamp.
Embodiment
Embodiment, as shown in Figure 2 and Figure 3, a kind of LED drive circuit, comprise power circuit 1, output circuit 2, voltage stabilizing circuit 3, amplifying circuit 4, sample circuit 5, Drive and Control Circuit 6, protective circuit 7 and the PFC correcting circuit 8 of electrical connection.
Drive and Control Circuit 6 comprises driving chip U1, resistance R 7, resistance R 24, capacitor C 10, diode D10, diode D11, resistance R 13, resistance R 14, current-limiting resistance R15, field effect transistor Q1, driving the model of chip U1 is SA7527, drives the end of the 1 pin connecting resistance R7 of chip U1, one end of resistance R 24, one end of capacitor C 10, the other end of resistance R 24, another termination of capacitor C 10 drives 2 pin of chip U1, the output of amplifying circuit 4, the input of another termination amplifying circuit 4 of resistance R 7, the positive pole of diode D10, the emitter of photoelectrical coupler U2, the negative pole of diode D10 connects the collector electrode of photoelectrical coupler U2, drive 8 pin of chip U1, drive 3 pin of chip U1 to connect PFC correcting circuit 8, drive 4 pin of chip U1 to connect protective circuit 7,5 pin that drive chip U1 connect the positive pole of diode D5 in power circuit 1 through resistance R 6, drive the 6 pin ground of chip U1, drive 7 pin of chip U1 to connect protective circuit 7, one end of resistance R 13, the negative pole of diode D11, the other end of resistance R 13, the positive pole of diode D11 connects the grid of field effect transistor Q1, the source electrode of field effect transistor Q1 is through current-limiting resistance R15 ground connection, resistance R 14 is connected between the source electrode of the grid of field effect transistor Q1 and field effect transistor Q1, the drain electrode of field effect transistor Q1 connects the positive pole of diode D6 in power circuit 1, and 8 pin that drive chip U1 connect the negative pole of diode D5 in power circuit 1 through resistance R 5.
Field effect transistor Q1 is consumable accessory, and punch through damage easily occurs.When himself damages, the high-low pressure of drain electrode can directly be added to from grid the drive output that drives chip U1, makes to drive chip U1 punch through damage, after adding protective circuit, can effectively protect the driving chip.
This circuit is multiple protective circuit.
After field effect transistor Q1 punctures, have large electric current and flow through current-limiting resistance R15, produce high voltage in current-limiting resistance R15 upper end, this high voltage can be added to the base stage of triode Q2, make triode Q2 saturated rapidly, the collector electrode of triode Q2 is shorted to ground, and the gate short of field effect transistor Q1, to ground, makes high voltage can not be added to the drive output that drives chip U1.Thereby protection drives chip U1.The high voltage that current-limiting resistance R15 upper end produces is added to the gate pole of thyristor VT simultaneously by capacitor C 12, make its conducting, and the anode voltage of thyristor VT is reduced to 0V, makes to drive chip U1 to be protected.Voltage-stabiliser tube ZD1, voltage-stabiliser tube ZD2: when the grid of field effect transistor Q1 has high voltage to occur, voltage-stabiliser tube ZD1, voltage-stabiliser tube ZD2 puncture, and make to drive chip U1 to be protected.When the grid voltage of field effect transistor Q1 is too high, have large electric current and flow through voltage-stabiliser tube ZD1, voltage-stabiliser tube ZD2 and thyristor VT, quick-break fuse FU quick-break, make to drive chip U1 and high voltage thoroughly to be isolated, and protection drives chip U1 effectively.
Those skilled in the art will recognize that; above-mentioned embodiment is exemplary; in order to make those skilled in the art can better understand the utility model content; should not be understood as the restriction to the utility model protection range; such as power circuit, output circuit, voltage stabilizing circuit, amplifying circuit, sample circuit, Drive and Control Circuit and PFC correcting circuit adopt other conventional circuit; so long as the improvement of doing according to technical solutions of the utility model all falls into protection range of the present utility model.
Claims (10)
1. a LED drive circuit, comprise Drive and Control Circuit (6), Drive and Control Circuit (6) comprises driving chip U1 and field effect transistor Q1, drive the drive output of chip U1 to connect the grid of field effect transistor Q1 through the diode D11 of reversal connection, it is characterized in that: described Drive and Control Circuit (6) is electrically connected with protective circuit (7), and driving the model of chip U1 is SA7527;
Described protective circuit (7) comprises triode Q2, and the collector electrode of triode Q2 connects the grid of field effect transistor Q1;
The base stage of described triode Q2 connects the source electrode of field effect transistor Q1, the grounded emitter of triode Q2.
2. a kind of LED drive circuit as claimed in claim 1, it is characterized in that: described protective circuit (7) comprises resistance R 12, capacitor C 12 and thyristor VT;
The anode of described thyristor VT connects the drive output that drives chip U1, the minus earth of thyristor VT;
The end of the gate pole connecting resistance R12 of described thyristor VT and an end of capacitor C 12;
The other end ground connection of described resistance R 12, the source electrode of another termination field effect transistor Q1 of capacitor C 12.
3. a kind of LED drive circuit as claimed in claim 2, it is characterized in that: described protective circuit (7) comprises voltage-stabiliser tube ZD1 and voltage-stabiliser tube ZD2;
The negative pole of described voltage-stabiliser tube ZD1 connects the drive output that drives chip U1, the plus earth of voltage-stabiliser tube ZD1;
The negative pole of described voltage-stabiliser tube ZD2 connects the positive pole of diode D11, the plus earth of voltage-stabiliser tube ZD2.
4. a kind of LED drive circuit as claimed in claim 3 is characterized in that: described protective circuit (7) comprises fast disconnected protective tube FU;
Described fast disconnected protective tube FU is arranged between the collector electrode of the negative pole of voltage-stabiliser tube ZD2 and triode Q2.
5. a kind of LED drive circuit as claimed in claim 4, it is characterized in that: 4 pin of described driving chip U1 connect the source electrode of field effect transistor Q1.
6. as one of them described a kind of LED drive circuit of claim 1-5, it is characterized in that: described Drive and Control Circuit (6) also comprises resistance R 14 and current-limiting resistance R15;
The source electrode of described field effect transistor Q1 is through current-limiting resistance R15 ground connection, and resistance R 14 is connected between the source electrode of the grid of field effect transistor Q1 and field effect transistor Q1.
7. a kind of LED drive circuit as claimed in claim 6, it is characterized in that: described LED drive circuit also comprises power circuit (1), voltage stabilizing circuit (3), amplifying circuit (4) and the sample circuit (5) of electrical connection;
Described Drive and Control Circuit (6) also comprises resistance R 7, resistance R 24, capacitor C 10, diode D10 and resistance R 13;
The end of the 1 pin connecting resistance R7 of described driving chip U1, an end of resistance R 24, an end of capacitor C 10, another termination of the other end of resistance R 24, capacitor C 10 drives 2 pin of chip U1 and the output of amplifying circuit (4).
8. a kind of LED drive circuit as claimed in claim 7, it is characterized in that: the input of another termination amplifying circuit (4) of described resistance R 7, the positive pole of diode D10 and sample circuit (5), the negative pole of diode D10 accesses sample circuit (5) and drives 8 pin of chip U1;
5 pin of described driving chip U1 connect power circuit (1) through resistance R 6, drive the 6 pin ground connection of chip U1, and resistance R 13 is in parallel with diode D11,
The drain electrode of described field effect transistor Q1 connects power circuit (1), drives 8 pin of chip U1 to connect power circuit (1) through resistance R 5.
9. a kind of LED drive circuit as claimed in claim 8, it is characterized in that: described power circuit (1) comprises rectifier bridge, diode D5, diode D6, resistance R 1, resistance R 2, capacitor C 3, capacitor C 4, capacitor C 5 and switch transformer T;
Described transformer T has the first primary coil, the second primary coil and secondary coil, and capacitor C 3 is connected between the positive pole and ground of rectifier bridge;
The positive pole of one termination rectifier bridge of described resistance R 1,8 pin of an end of another termination capacitor C 4 of resistance R 1, the negative pole of diode D5 and driving chip U1, the other end ground connection of capacitor C 4;
The positive pole of described diode D5 connects an end of the first primary coil, 5 pin of driving chip U1, the other end ground connection of the first primary coil.
10. a kind of LED drive circuit as claimed in claim 9, is characterized in that: the positive pole of an end of described capacitor C 5, a termination rectifier bridge of resistance R 2, the negative pole of another terminating diode D6 of the other end of capacitor C 5, resistance R 2;
The positive pole of one termination rectifier bridge of described the second primary coil, the positive pole of another terminating diode D6 of the second primary coil, the drain electrode of field effect transistor Q1.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN 201320359451 CN203368835U (en) | 2013-06-22 | 2013-06-22 | LED drive circuit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN 201320359451 CN203368835U (en) | 2013-06-22 | 2013-06-22 | LED drive circuit |
Publications (1)
Publication Number | Publication Date |
---|---|
CN203368835U true CN203368835U (en) | 2013-12-25 |
Family
ID=49816543
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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CN 201320359451 Expired - Fee Related CN203368835U (en) | 2013-06-22 | 2013-06-22 | LED drive circuit |
Country Status (1)
Country | Link |
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CN (1) | CN203368835U (en) |
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2013
- 2013-06-22 CN CN 201320359451 patent/CN203368835U/en not_active Expired - Fee Related
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Legal Events
Date | Code | Title | Description |
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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: 20131225 Termination date: 20140622 |
|
EXPY | Termination of patent right or utility model |