CN104780638A - LED lamp overheat protection circuit - Google Patents
LED lamp overheat protection circuit Download PDFInfo
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- CN104780638A CN104780638A CN201410013280.XA CN201410013280A CN104780638A CN 104780638 A CN104780638 A CN 104780638A CN 201410013280 A CN201410013280 A CN 201410013280A CN 104780638 A CN104780638 A CN 104780638A
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Abstract
An embodiment of the invention discloses an LED lamp overheat protection circuit comprising an LED driving module, an LED lamp, a thermistor, a control chip, and a relay. One end of the thermistor is connected to the negative electrode of a power supply, and the other end of the thermistor is connected with the threshold end of the control chip. The output end of the control chip is connected with the power input end of the relay, the common end of the relay is connected to the positive electrode of the power supply, the normally closed end of the relay is suspended, and the normally open end of the relay is connected with the power input end of the driving module. The output end of the driving module is connected with the LED lamp. The control chip controls the state of the relay according to the voltage under different resistances of the thermistor, the state of the LED driving module is determined by the state of the relay, and thus, on-off of the LED lamp is determined. By adopting the LED lamp overheat protection circuit of the invention, the LED lamp can be turned off when the temperature of the LED lamp is too high, and the safety of the LED lamp is improved.
Description
Technical field
The present invention relates to electronic technology field, particularly relate to a kind of LED overheating protection circuit.
Background technology
Along with the development of electronic technology, the requirement of user to lighting apparatus is more and more higher.Wherein, safety index has become the important references factor that user selects lighting apparatus.LED is when long-time use or LED drive circuit short circuit, and its temperature will raise, and too high temperature will cause all kinds of security incident.
Summary of the invention
Embodiment of the present invention technical problem to be solved is, provides a kind of LED overheating protection circuit, can be implemented in the temperature of LED too high time turn off the function of LED, improve the fail safe of LED.
In order to solve the problems of the technologies described above, embodiments provide a kind of LED overheating protection circuit, comprising LED drive module, LED, thermistor, control chip and relay, wherein:
The negative pole of one end access power supply of described thermistor, the other end of described thermistor is connected with the thresholding end of described control chip, the output of described control chip is connected with the power input of described relay, the positive pole of the common port access power supply of described relay, the normal-closed end of described relay is unsettled, the Chang Kaiduan of described relay is connected with the power input of described driver module, the output of described driver module is connected with the anode of described LED, the negative pole of the negative electrode access power supply of described LED;
Described thermistor is for detecting the temperature of described LED drive module and described LED, described control chip controls the state of described relay according to the voltage of described thermistor under different resistance, the state of described relay determines the state of described LED drive module, and then determines the light on and off of described LED.
Implement the embodiment of the present invention, there is following beneficial effect: in the embodiment of the present invention, thermistor changes self resistance according to the temperature of LED, and then change the output level of control chip, thus control the on off state of LED, realize the function turning off LED when the temperature of LED is too high, improve the fail safe of LED.
Accompanying drawing explanation
In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.
Fig. 1 is the circuit theory diagrams of a kind of LED overheating protection circuit that the embodiment of the present invention provides.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, be clearly and completely described the technical scheme in the embodiment of the present invention, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.
Fig. 1 is the circuit theory diagrams of a kind of LED overheating protection circuit in the embodiment of the present invention.LED overheating protection circuit as shown in the figure in the embodiment of the present invention at least can comprise LED drive module, LED, thermistor, control chip and relay, wherein:
The negative pole of one end access power supply of thermistor, the other end of thermistor is connected with the thresholding end of control chip, the output of control chip is connected with the power input of relay, the positive pole of the common port access power supply of relay, the normal-closed end of relay is unsettled, the Chang Kaiduan of relay is connected with the power input of driver module, and the output of driver module is connected with the anode of LED, the negative pole of the negative electrode access power supply of LED;
Thermistor is for detecting the temperature of LED drive module and LED, and control chip carrys out the state of control relay according to the voltage of thermistor under different resistance, and the state of relay determines the state of LED drive module, and then determines the light on and off of LED.
Optionally; LED overheating protection circuit also comprises indicator light and semiconductor chilling plate; the output of control chip is connected with the anode of indicator light; the negative pole of the negative electrode access power supply of indicator light; the output of control chip is connected with the power input of semiconductor chilling plate; the negative pole of the earth terminal access power supply of semiconductor chilling plate, described semiconductor chilling plate is used for described LED or LED drive module refrigeration.
Further; LED overheating protection circuit also comprises the first triode and the second triode; accordingly; the output of control chip is connected with the base stage of the first triode; the positive pole of the collector electrode access power supply of the first triode, the emitter of the first triode is connected with the power input of semiconductor chilling plate, and the output of control chip is connected with the base stage of the second triode; the positive pole of the collector electrode access power supply of the second triode, the emitter of the second triode is connected with the power input of relay.
Further, LED overheating protection circuit also comprises current-limiting resistance, and accordingly, the output of described control chip is connected with the base stage of described first triode, the base stage of described second triode and described indicator light anode by described current-limiting resistance.
Optionally, LED overheating protection circuit also comprises potentiometer and storage capacitor, wherein; one end access positive source of potentiometer; the other end of potentiometer is connected with the anode of storage capacitor, and the thresholding end of control chip is connected with the anode of storage capacitor, the negative electrode access power cathode of storage capacitor.When storage capacitor is full of electricity, its anode is high level.
Optionally, LED overheating protection circuit also comprises filter capacitor, the anode access positive source of filter capacitor, the negative electrode access power cathode of filter capacitor.
Optionally, the model of control chip is 555A.
Refer to Fig. 1, the circuit theory diagrams of a kind of LED overheating protection circuit as shown in the figure, wherein; thermistor is Rp, and control chip is 555A, and the thresholding end of control chip is 6 ends; relay is K, and the common port of relay is K-1, and the normal-closed end of relay is 1 end; the Chang Kaiduan of relay is 2 ends, and indicator light is LED1, and the first triode is Q1; second triode is Q2, and current-limiting resistance is R2, and potentiometer is RP; charging capacitor is C2, and filter capacitor is C1.It is pointed out that the trigger end of control chip is 2 ends, in embodiments of the present invention, 2 ends are connected with 6 ends.
In specific implementation process, after LED overheating protection circuit works on power, the temperature of LED and LED drive module is higher, then the resistance of thermistor Rp is less, wherein:
When the temperature of LED and LED drive module is not higher than predetermined threshold value, the resistance of thermistor Rp is higher than preset resistive value, after potentiometer RP dividing potential drop, the other end of thermistor Rp is high level, and then thresholding end 6 end of control chip 555A and trigger end 2 termination receive high level, according to the characteristic of control chip 555A, its output 3 end is by output low level, second triode Q2 receives low level and not conducting because of base stage, relay K does not power on, and then common port K-1 and Chang Kaiduan 2 end of relay K is connected, thus LED drive module powers on, and LED is luminous;
When the temperature of LED or LED drive module is higher than predetermined threshold value, the resistance of thermistor Rp is lower than preset resistive value, after potentiometer RP dividing potential drop, the other end of thermistor Rp is low level, and then thresholding end 6 end of control chip 555A and trigger end 2 termination receive low level, according to the characteristic of control chip 555A, its output 3 end will export high level, second triode Q2 receives high level and conducting because of base stage, the power input of relay K accesses the positive pole of power supply by the second triode Q2, relay K powers on, and then the common port K-1 of relay K is connected with normal-closed end 1 end, thus LED drive module power down, LED is not luminous.
It is pointed out that the resistance by regulator potentiometer RP, the dividing potential drop of thermistor Rp can be changed, and then the preset resistive value of thermistor Rp can be regulated, thus regulate the predetermined threshold value of the temperature of LED and LED drive module.
Accordingly, when the temperature of LED or LED drive module is higher than predetermined threshold value, control chip 555A exports high level, and by lighting indicator light LED1 after current-limiting resistance R2, whether the light on and off condition adjudgement light fixture by indicator light LED1 is in superheat state.
Accordingly, when the temperature of LED or LED drive module is higher than predetermined threshold value, control chip 555A exports high level, first triode Q1 receives high level and conducting because of base stage, the power input of semiconductor chilling plate is by the first triode access positive source, and semiconductor chilling plate powers on and freezes to LED or LED drive module.
In the embodiment of the present invention, thermistor changes self resistance according to the temperature of LED, and then change the output level of control chip, thus control the on off state of LED, realize the function turning off LED when the temperature of LED is too high, improve the fail safe of LED.
Above disclosedly be only present pre-ferred embodiments, certainly can not limit the interest field of the present invention with this, therefore according to the equivalent variations that the claims in the present invention are done, still belong to the scope that the present invention is contained.
Claims (10)
1. a LED overheating protection circuit, is characterized in that, described circuit comprises LED drive module, LED, thermistor, control chip and relay, wherein:
The negative pole of one end access power supply of described thermistor, the other end of described thermistor is connected with the thresholding end of described control chip, the output of described control chip is connected with the power input of described relay, the positive pole of the common port access power supply of described relay, the normal-closed end of described relay is unsettled, the Chang Kaiduan of described relay is connected with the power input of described driver module, the output of described driver module is connected with the anode of described LED, the negative pole of the negative electrode access power supply of described LED;
Described thermistor is for detecting the temperature of described LED drive module and described LED, described control chip controls the state of described relay according to the voltage of described thermistor under different resistance, the state of described relay determines the state of described LED drive module, and then determines the light on and off of described LED.
2. LED overheating protection circuit as claimed in claim 1, it is characterized in that, the temperature of described LED and described LED drive module is higher, then the resistance of described thermistor is less, wherein:
When the temperature of described LED and described LED drive module is not higher than predetermined threshold value, the resistance of described thermistor is higher than preset resistive value, the other end of described thermistor is high level, and then the thresholding termination of described control chip receives high level, the output output low level of described control chip, described relay does not power on, and then the common port of described relay is connected with Chang Kaiduan, thus described LED drive module powers on, described LED is luminous;
When the temperature of described LED or described LED drive module is higher than described predetermined threshold value, the resistance of described thermistor is lower than preset resistive value, the other end of described thermistor is low level, and then the thresholding termination of described control chip receives low level, the output of described control chip exports high level, and described relay powers on, and then the common port of described relay is connected with normal-closed end, thus described LED drive module power down, described LED is not luminous.
3. LED overheating protection circuit as claimed in claim 2, it is characterized in that, described circuit also comprises indicator light and semiconductor chilling plate, the output of described control chip is connected with the anode of described indicator light, the negative pole of the negative electrode access power supply of described indicator light, the output of described control chip is connected with the power input of described semiconductor chilling plate, the negative pole of the earth terminal access power supply of described semiconductor chilling plate;
Described semiconductor chilling plate is used for described LED or LED drive module refrigeration.
4. LED overheating protection circuit as claimed in claim 3, is characterized in that,
When the output of described control chip exports high level, described semiconductor chilling plate powers on, and described indicator light is luminous.
5. LED overheating protection circuit as claimed in claim 3, it is characterized in that, described circuit also comprises the first triode and the second triode,
The output of described control chip is connected with the power input of described semiconductor chilling plate and comprises:
The output of described control chip is connected with the base stage of described first triode, the positive pole of the collector electrode access power supply of described first triode, and the emitter of described first triode is connected with the power input of described semiconductor chilling plate;
The output of described control chip is connected with the power input of described relay and comprises:
The output of described control chip is connected with the base stage of described second triode, and the positive pole of the collector electrode access power supply of described second triode, the emitter of described second triode is connected with the power input of described relay.
6. LED overheating protection circuit as claimed in claim 5, is characterized in that,
When the output of described control chip exports high level, described semiconductor chilling plate powers on and comprises:
When the output of described control chip exports high level, described first triode ON, the power input of described semiconductor chilling plate accesses the positive pole of power supply by the first triode, described semiconductor chilling plate powers on;
The output of described control chip exports high level, and described relay powers on and comprises:
The output of described control chip exports high level, described second triode ON, and the power input of described relay accesses the negative pole of power supply by the second triode, described relay powers on.
7. LED overheating protection circuit as claimed in claim 5, it is characterized in that, described circuit also comprises current-limiting resistance,
The output of described control chip is connected with the base stage of described first triode, and
The output of described control chip is connected with the base stage of described second triode, and
The output of described control chip is connected with described indicator light anode and comprises:
The output of described control chip is connected with the base stage of described first triode, the base stage of described second triode and described indicator light anode by described current-limiting resistance.
8. LED overheating protection circuit as claimed in claim 1; it is characterized in that; described circuit also comprises potentiometer and storage capacitor; one end access positive source of described potentiometer; the other end of described potentiometer is connected with the anode of described storage capacitor; the thresholding end of described control chip is connected with the anode of described storage capacitor, the negative electrode access power cathode of described storage capacitor.
9. LED overheating protection circuit as claimed in claim 1, it is characterized in that, described circuit also comprises filter capacitor, the anode access positive source of described filter capacitor, the negative electrode access power cathode of described filter capacitor.
10. LED overheating protection circuit as claimed in claim 1, it is characterized in that, the model of described control chip is 555A.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410013280.XA CN104780638B (en) | 2014-01-10 | 2014-01-10 | A kind of LED light overheating protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410013280.XA CN104780638B (en) | 2014-01-10 | 2014-01-10 | A kind of LED light overheating protection circuit |
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| Publication Number | Publication Date |
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| CN104780638A true CN104780638A (en) | 2015-07-15 |
| CN104780638B CN104780638B (en) | 2019-04-16 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201410013280.XA Active CN104780638B (en) | 2014-01-10 | 2014-01-10 | A kind of LED light overheating protection circuit |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111542151A (en) * | 2020-06-17 | 2020-08-14 | 东莞职业技术学院 | Lamp control circuit and lamp thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101029724A (en) * | 2006-09-29 | 2007-09-05 | 申家群 | Water-proof radiator and infrared refrigerating transmitter |
| CN201636035U (en) * | 2009-12-14 | 2010-11-17 | 邱星辉 | Electric fan capable of automatically opening and closing according to temperature |
| CN103001177A (en) * | 2011-09-19 | 2013-03-27 | 海洋王（东莞）照明科技有限公司 | LED lamp and overheat protecting circuit thereof |
| CN203177483U (en) * | 2013-02-04 | 2013-09-04 | 北京联合大学 | Water temperature controller |
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2014
- 2014-01-10 CN CN201410013280.XA patent/CN104780638B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101029724A (en) * | 2006-09-29 | 2007-09-05 | 申家群 | Water-proof radiator and infrared refrigerating transmitter |
| CN201636035U (en) * | 2009-12-14 | 2010-11-17 | 邱星辉 | Electric fan capable of automatically opening and closing according to temperature |
| CN103001177A (en) * | 2011-09-19 | 2013-03-27 | 海洋王（东莞）照明科技有限公司 | LED lamp and overheat protecting circuit thereof |
| CN203177483U (en) * | 2013-02-04 | 2013-09-04 | 北京联合大学 | Water temperature controller |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111542151A (en) * | 2020-06-17 | 2020-08-14 | 东莞职业技术学院 | Lamp control circuit and lamp thereof |
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| CN104780638B (en) | 2019-04-16 |
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