CN202652655U - Led constant current drive circuit - Google Patents
Led constant current drive circuit Download PDFInfo
- Publication number
- CN202652655U CN202652655U CN 201220316407 CN201220316407U CN202652655U CN 202652655 U CN202652655 U CN 202652655U CN 201220316407 CN201220316407 CN 201220316407 CN 201220316407 U CN201220316407 U CN 201220316407U CN 202652655 U CN202652655 U CN 202652655U
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- comparator
- emitting diode
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- triode
- light
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Abstract
The utility model discloses a LED constant current drive circuit, comprising a first comparator, a second comparator, a first resistor, a first triode and a light emitting diode set. The light emitting diode set comprises a plurality of light emitting diodes in series connection and each light emitting diode in the light emitting diode set is in parallel connection with a reversal connection voltage-stabiliser tube. One terminal of the first resistor is in connection with an anti-phase input terminal of the first comparator and the other terminal is in connection with lines between an output terminal of the first comparator and an in-phase input terminal of the second comparator. An output terminal of the second comparator is in connection with a base electrode of the first triode; an anti-phase input terminal of the second comparator is in connection with an emitter electrode of the first triode; the first comparator is in connection with a direct current voltage input line and a trigger voltage input line; an output terminal of the light emitting diode set is in connection with a collector electrode of the first triode; an input terminal of the light emitting diode set is in connection with the direct current voltage input line. The LED constant current drive circuit has the characteristics of low costs and a small size and can raise application reliability.
Description
Technical field
The utility model relates to a kind of drive circuit, specifically the LED constant-current drive circuit.
Background technology
LED has that volume is little, low cost and other advantages, so people usually are used for LED the input of some systems, and whether lights to judge by the LED lamp whether signal is connected in the system when system testing.As a semiconductor device that is operated in low-voltage, direct current, LED needs to work under constant electric current environment.Mains-supplied commonly used during general system power supply if need LED luminous when detecting in system, then needs to carry out rectification control by drive circuit to alternating voltage rear for LED.By the electrology characteristic of LED as can be known, the mean forward current of LED is along with the increase of forward voltage presents significantly linear growth, the change of LED its forward voltage behind forward conduction will cause that the LED miscarriage that powers on gives birth to very large variation, and electric current is very large on the impact of LED junction temperature, and excessive electric current is easy to cause LED to damage because junction temperature raises.Damage and the accuracy of impact test the defective such as there is complex structure in existing LED constant-current drive circuit, components and parts are many, cost is high and reliability is low for fear of LED.
The utility model content
The purpose of this utility model is to overcome the deficiencies in the prior art, provide a kind of simple in structure, cost is low, and the high LED constant-current drive circuit of reliability.
The purpose of this utility model is achieved through the following technical solutions: the LED constant-current drive circuit, comprise the first comparator, the second comparator, the first resistance, the first triode and light-emitting diode group, described light-emitting diode group comprises the light-emitting diode of a plurality of series connection, and all is parallel with the voltage-stabiliser tube of a reversal connection in the light-emitting diode group on each light-emitting diode; The output of described the first comparator is connected with the in-phase input end of the second comparator, described the first resistance one end is connected on the inverting input of the first comparator, connection between its other end and the first comparator output terminal and the second comparator in-phase input end, the output of described the second comparator is connected with the base stage of the first triode, the inverting input of the second comparator is connected with the first transistor emitter, connect the direct voltage input line on the first comparator, be connected with the trigger voltage input line on the first comparator in-phase input end, the output of described light-emitting diode group is connected with the collector electrode of the first triode, and the input of light-emitting diode group is connected on the direct voltage input line.The direct voltage input line specifically is connected on the forward voltage input of the first comparator, the utility model when using, direct voltage input line external direct current power supply, the system power supply voltage after the external rectification conversion of trigger voltage input line.
The LED constant-current drive circuit also comprises the second resistance and the 3rd resistance, and described the second resistance one end is connected on the circuit between the first comparator inverting input and the first resistance, its other end ground connection; Described the 3rd resistance one end connects on the circuit between the second comparator inverting input and the first transistor emitter, its other end ground connection.
Described the first resistance is adjustable resistance.
Described the first triode is NPN type triode.
As preferably, described light-emitting diode group comprises the light-emitting diode of three series connection.
Compared with prior art, the utlity model has following beneficial effect: (1) the utility model comprises the first comparator, the second comparator, the first resistance, the first triode and light-emitting diode group, overall structure is simple, be convenient to realize, used components and parts are few, cost is low, wherein, connect the direct voltage input line on the first comparator, be connected with the trigger voltage input line on the first comparator in-phase input end, when the utility model is used for system testing, voltage by treating examining system is as trigger voltage of the present utility model, and the direct voltage of inputting on the direct voltage input line makes the supply power voltage of lumination of light emitting diode stable just as the supply power voltage of light-emitting diode, thereby can not damage because variation in voltage on the light-emitting diode causes light-emitting diode, improve the reliability when the utility model is used.
(2) light-emitting diode group of the present utility model comprises the light-emitting diode of a plurality of series connection; and all be parallel with the voltage-stabiliser tube of a reversal connection in the light-emitting diode group on each light-emitting diode; so; when the utility model is used; the branch road that voltage-stabiliser tube in parallel consists of on each light-emitting diode consists of protective circuit of the present utility model; when the lamp pearl of certain light-emitting diode is opened circuit; the voltage-stabiliser tube in parallel with it devoted oneself to work; thereby can avoid circuit to open circuit; the utility model can avoid single light-emitting diode to damage when using and the erroneous judgement that causes, has further improved the reliability when the utility model is used.
Description of drawings
Fig. 1 is the structural representation of the utility model embodiment.
The corresponding name of Reference numeral is called in the accompanying drawing: A1-first comparator, A2-second comparator, R1-first resistance, R2-second resistance, R3-the 3rd resistance, Q1-first triode, LED1-first light-emitting diode, LED2-second light-emitting diode, LED3-the 3rd light-emitting diode, DW1-first voltage-stabiliser tube, DW2-second voltage-stabiliser tube, DW3-the 3rd voltage-stabiliser tube, 1-trigger voltage input line, 2-direct voltage input line.
Embodiment
The utility model is described in further detail below in conjunction with embodiment and accompanying drawing, but execution mode of the present utility model is not limited to this.
Embodiment:
As shown in Figure 1, the LED constant-current drive circuit, comprise the first comparator A1, the second comparator A2, the first resistance R 1, the second resistance R 2, the 3rd resistance R 3, the first triode Q1 and light-emitting diode group, the first resistance R 1 is adjustable resistance, the first triode Q1 is NPN type triode, the light-emitting diode group comprises the light-emitting diode of three series connection, three light-emitting diodes are respectively the first LED 1, be parallel with respectively the first voltage-stabiliser tube DW1 of reversal connection on the second LED 2 and 3, three light-emitting diodes of the 3rd LED, the second voltage-stabiliser tube DW2 and the 3rd voltage-stabiliser tube DW3.The output of the first comparator A1 is connected with the in-phase input end of the second comparator A2, the first resistance R 1 one ends are connected on the inverting input of the first comparator A1, the connection between its other end and the first comparator A1 output and the second comparator A2 in-phase input end.The output of the second comparator A2 is connected with the base stage of the first triode Q1, the inverting input of the second comparator A2 is connected with the first triode Q1 emitter, the upper direct voltage input line 2 that is used for external direct current power supply that connects of the first comparator A1, be connected with trigger voltage input line 1 on the first comparator A1 in-phase input end, trigger voltage input line 1 is used for receiving the voltage input after the system to be tested rectification.The output of light-emitting diode group is connected with the collector electrode of the first triode Q1, and light-emitting diode group input is connected on the direct voltage input line 2.As preferably, the first comparator A1 and the second comparator A2 all adopt LM358 in the present embodiment.
The second resistance R 2 one ends are connected on the circuit between the first comparator A1 inverting input and the first resistance R 1, and it connects the other end ground connection of the line scan pickup coil side between the first comparator A1 inverting input and the first resistance R 1 relatively.The 3rd resistance R 3 one ends connect on the circuit between the second comparator A2 inverting input and the first triode Q1 emitter, and it connects the other end ground connection of the line scan pickup coil side between the second comparator A2 inverting input and the first triode Q1 emitter relatively.
As mentioned above, then can well realize the utility model.
Claims (5)
1.LED constant-current drive circuit, it is characterized in that: comprise the first comparator (A1), the second comparator (A2), the first resistance (R1), the first triode (Q1) and light-emitting diode group, described light-emitting diode group comprises the light-emitting diode of a plurality of series connection, and all is parallel with the voltage-stabiliser tube of a reversal connection in the light-emitting diode group on each light-emitting diode; The output of described the first comparator (A1) is connected with the in-phase input end of the second comparator (A2), described the first resistance (R1) end is connected on the inverting input of the first comparator (A1), connection between its other end and the first comparator (A1) output and the second comparator (A2) in-phase input end, the output of described the second comparator (A2) is connected with the base stage of the first triode (Q1), the inverting input of the second comparator (A2) is connected with the first triode (Q1) emitter, the upper direct voltage input line (2) that connects of the first comparator (A1), be connected with trigger voltage input line (1) on the first comparator (A1) in-phase input end, the output of described light-emitting diode group is connected with the collector electrode of the first triode (Q1), and the input of light-emitting diode group is connected on the direct voltage input line (2).
2. LED constant-current drive circuit according to claim 1, it is characterized in that: also comprise the second resistance (R2) and the 3rd resistance (R3), described the second resistance (R2) end is connected on the circuit between the first comparator (A1) inverting input and the first resistance (R1), its other end ground connection; Described the 3rd resistance (R3) end connects on the circuit between the second comparator (A2) inverting input and the first triode (Q1) emitter, its other end ground connection.
3. LED constant-current drive circuit according to claim 1, it is characterized in that: described the first resistance (R1) is adjustable resistance.
4. LED constant-current drive circuit according to claim 1, it is characterized in that: described the first triode (Q1) is NPN type triode.
5. described any LED constant-current drive circuit according to claim 1～4, it is characterized in that: described light-emitting diode group comprises the light-emitting diode of three series connection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220316407 CN202652655U (en) | 2012-07-03 | 2012-07-03 | Led constant current drive circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220316407 CN202652655U (en) | 2012-07-03 | 2012-07-03 | Led constant current drive circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202652655U true CN202652655U (en) | 2013-01-02 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201220316407 Expired - Fee Related CN202652655U (en) | 2012-07-03 | 2012-07-03 | Led constant current drive circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202652655U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103148393A (en) * | 2013-03-16 | 2013-06-12 | 李忠训 | LED 5050 module based on high voltage constant current technology |
| CN103533696A (en) * | 2012-07-03 | 2014-01-22 | 成都市宏山科技有限公司 | LED constant-current driving circuit |
| CN109939254A (en) * | 2019-03-29 | 2019-06-28 | 陈芸 | A kind of surgical instrument bag disinfection state identification device |
-
2012
- 2012-07-03 CN CN 201220316407 patent/CN202652655U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103533696A (en) * | 2012-07-03 | 2014-01-22 | 成都市宏山科技有限公司 | LED constant-current driving circuit |
| CN103148393A (en) * | 2013-03-16 | 2013-06-12 | 李忠训 | LED 5050 module based on high voltage constant current technology |
| CN103148393B (en) * | 2013-03-16 | 2015-06-24 | 李忠训 | LED 5050 module based on high voltage constant current technology |
| CN109939254A (en) * | 2019-03-29 | 2019-06-28 | 陈芸 | A kind of surgical instrument bag disinfection state identification device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130102 Termination date: 20130703 |