CN203608439U - LED constant current power supply with over-temperature protection - Google Patents
LED constant current power supply with over-temperature protection Download PDFInfo
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- CN203608439U CN203608439U CN201320857640.5U CN201320857640U CN203608439U CN 203608439 U CN203608439 U CN 203608439U CN 201320857640 U CN201320857640 U CN 201320857640U CN 203608439 U CN203608439 U CN 203608439U
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Abstract
The utility model relates to a LED constant current power supply with over-temperature protection. The power supply comprises a LED module group, an input rectification filter circuit, a switch power supply circuit, a PWM control circuit, a current feedback circuit and an output rectification filter circuit. An input terminal of the input rectification filter circuit is connected with an electric supply and an output terminal is connected with the LED module group successively through the switch power supply circuit and the output rectification filter circuit. An input terminal of the PWM control circuit is connected with the LED module group through the current feedback circuit and an output terminal is connected with the switch power supply circuit. A temperature detection device is also included. The temperature detection device detects a temperature signal of the LED module group and transmits the temperature signal to the input terminal of the PWM control circuit. The PWM control circuit timely adjusts a current output by the switch power supply circuit according to a LED temperature change detected by a thermistor, ensures that the temperature of the LED is in a proper scope and can timely carry out reaction to a sudden temperature anomaly of the LED. A service life of the LED is prolonged.
Description
Technical field
The utility model relates to constant-current supply field, is specifically related to a kind of LED constant-current supply with overheat protector.
Background technology
LED is a kind of low-voltage unilateal conduction device of current drives, belong to semiconductor power device, its volt-ampere characteristic is non-linear, the electric current that flows through PN junction is not directly proportional to the voltage that is carried in PN junction two ends, in the time that voltage has less variation, the electric current that flows through PN junction will have a greater change, PN junction has negative temperature coefficient simultaneously, temperature raises, tube voltage drop reduces, the electric current that flows through chip is further increased, if adopt constant voltage source to drive, very easily cause the electric current Yin Wendu in chip raise and sharply increase, cause spectral shift, cause light decay, serious meeting causes LED to burn, current most of LED driving power all adopts constant current drive mode, but constant-current supply is forbidden load cut-off, and output voltage is along with changing easily appears in the variation of load resistance within the specific limits, and when actual use, the quantity of LED is restricted.Current LED constant-current driving power supply does not have temperature protective device, can not adjust in time input current according to the variations in temperature of LED, and the actual life of LED is well below theoretical service life, and cannot tackle LED burst temperature anomaly.
Summary of the invention
The technical problems to be solved in the utility model is to provide a kind of LED constant-current supply with overheat protector; can solve existing LED constant-current supply and can not adjust in time input current according to the variations in temperature of LED; cause the actual life of LED well below theoretical service life, and cannot tackle the problem of LED burst temperature anomaly.
The utility model is achieved through the following technical solutions:
A kind of LED constant-current supply with overheat protector, comprise LED module, input rectifying filter circuit, switching power circuit, pwm control circuit, current feedback circuit, output rectifier and filter, the input of described input rectifying filter circuit connects civil power, output is successively through switching power circuit, output rectifier and filter connects LED module, the input of described pwm control circuit connects LED module by current feedback circuit, output connecting valve power circuit also comprises temperature-detecting device, described temperature-detecting device detects the temperature signal of LED module, and temperature signal is transferred to pwm control circuit input.
The civil power exchanging is converted to input switch power circuit after direct current by resistance R 1, capacitor C 1, full bridge rectifier D1, inductance L 1, capacitor C 2, the rectifier diode D2 of composition input rectifying filter circuit successively.
Described switch power supply route enhancement mode N raceway groove isolated gate FET Q1 and transformer T1 composition, the source electrode of described field effect transistor Q1 is by resistance R 2 ground connection, grid is connected in the output of pwm control circuit, and drain electrode connects the output of input rectifying filter circuit by transformer T1 armature winding; The secondary winding of described transformer T1 connects output rectifier and filter.
Described current rectifying and wave filtering circuit is made up of rectifier diode D3 and capacitor C 3, and the output of switching power circuit is connected LED module through rectifier diode D3 with capacitor C 3 successively.
Described current feedback circuit comprises the resistance R 4 and the operational amplifier U1 that connect with LED module, the output of described operational amplifier U1 is connected in the input of pwm control circuit, the in-phase input end of described operational amplifier U1 is connected with reference voltage, and the inverting input of described operational amplifier U1 is connected in the common port of resistance R 4 and LED module.
Described temperature-detecting device is the PTC thermistor that is parallel to LED module.
The power end of described pwm control circuit is connected in the output of input rectifying filter circuit by resistance R 3.
Described LED module is in series by multiple LED lamps, and each LED lamp respectively reverse parallel connection has Zener diode D4.
The utility model advantage is compared with prior art:
The LED variations in temperature that pwm control circuit detects according to thermistor is adjusted the electric current of switching power circuit output in time, guarantees that the temperature of LED, in suitable scope, also can react in time to the burst temperature anomaly of LED, extends the useful life of LED.
Accompanying drawing explanation
Fig. 1 is structured flowchart of the present utility model.
Fig. 2 is circuit diagram of the present utility model.
Embodiment
A kind of LED constant-current supply with overheat protector as depicted in figs. 1 and 2, comprise LED module, input rectifying filter circuit, switching power circuit, pwm control circuit, current feedback circuit, output rectifier and filter, the input of described input rectifying filter circuit connects civil power, output is successively through switching power circuit, output rectifier and filter connects LED module, the input of described pwm control circuit connects LED module by current feedback circuit, output connecting valve power circuit also comprises temperature-detecting device, the power end of described pwm control circuit is connected in the output of input rectifying filter circuit by resistance R 3, described temperature-detecting device detects the temperature signal of LED module, and temperature signal is transferred to pwm control circuit input.
The civil power of alternating current 220V is converted to input switch power circuit after 350V direct current by resistance R 1, capacitor C 1, full bridge rectifier D1, inductance L 1, capacitor C 2, the rectifier diode D2 of composition input rectifying filter circuit successively.
Described switch power supply route enhancement mode N raceway groove isolated gate FET Q1 and transformer T1 composition, the source electrode of described field effect transistor Q1 is by resistance R 2 ground connection, grid is connected in the output of pwm control circuit, and drain electrode connects the output of input rectifying filter circuit by transformer T1 armature winding; The secondary winding of described transformer T1 connects output rectifier and filter.
Described current rectifying and wave filtering circuit is made up of rectifier diode D3 and capacitor C 3, and the output of switching power circuit is connected LED module through rectifier diode D3 with capacitor C 3 successively.
Described current feedback circuit comprises the resistance R 4 and the operational amplifier U1 that connect with LED module, the output of described operational amplifier U1 is connected in the input of pwm control circuit, the in-phase input end of described operational amplifier U1 is connected with reference voltage, and the inverting input of described operational amplifier U1 is connected in the common port of resistance R 4 and LED module, resistance R 4 is connected with LED module, the electric current that flows through LED module also flows through resistance R 4 simultaneously, in the time flowing through the electric current of LED module and change, the electric current of this conversion can produce one and change voltage at resistance R 4 two ends, this variation voltage joins the inverting input of operational amplifier U1, the reference voltage that changes voltage and the access of operational amplifier U1 in-phase input end compares, obtain the variation voltage being exaggerated at the output of operational amplifier U1, the variation voltage input pwm control circuit of this amplification, change the duty ratio of PWM output rectangular voltage, thereby the frequency of oscillation of control switch power supply, and then the output voltage of change Switching Power Supply, make the electric current in LED module remain constant.
Described temperature-detecting device is the PTC thermistor that is parallel to LED module, PTC thermistor is installed near LED module, detect the variation of LED module temperature, when LED module temperature raises, PTC thermistor resistance increases, and its both end voltage raises immediately, and the voltage of increase is input to operational amplifier U1 inverting input, compare with reference voltage, the variable signal feedback pwm control circuit relatively amplifying reduces to input the electric current of LED module; By design temperature upper limit value and lower limit value, in the time that exceeding upper limit value and lower limit value, reduces LED module real time temperature or increases the electric current of input LED module, if when temperature rise exceedes the alarming value of setting, pwm control circuit cuts off electric current by switching power circuit, thereby reach the object of temperature control.
Described LED module is in series by multiple LED lamps; each LED lamp respectively reverse parallel connection has Zener diode D4, and the puncture voltage of Zener diode D4 is higher than the operating voltage of LED lamp, when LED lamp opens circuit or when both end voltage raises; Zener diode punctures, thus protection LED lamp.
Claims (8)
1. the LED constant-current supply with overheat protector, comprise LED module, input rectifying filter circuit, switching power circuit, pwm control circuit, current feedback circuit, output rectifier and filter, the input of described input rectifying filter circuit connects civil power, output is successively through switching power circuit, output rectifier and filter connects LED module, the input of described pwm control circuit connects LED module by current feedback circuit, output connecting valve power circuit, it is characterized in that: also comprise temperature-detecting device, described temperature-detecting device detects the temperature signal of LED module, and temperature signal is transferred to pwm control circuit input.
2. a kind of LED constant-current supply with overheat protector as claimed in claim 1, is characterized in that: the civil power of interchange is converted to input switch power circuit after direct current by resistance R 1, capacitor C 1, full bridge rectifier D1, inductance L 1, capacitor C 2, the rectifier diode D2 of composition input rectifying filter circuit successively.
3. a kind of LED constant-current supply with overheat protector as claimed in claim 1, it is characterized in that: described switch power supply route enhancement mode N raceway groove isolated gate FET Q1 and transformer T1 composition, the source electrode of described field effect transistor Q1 is by resistance R 2 ground connection, grid is connected in the output of pwm control circuit, and drain electrode connects the output of input rectifying filter circuit by transformer T1 armature winding; The secondary winding of described transformer T1 connects output rectifier and filter.
4. a kind of LED constant-current supply with overheat protector as described in claim 1 or 3; it is characterized in that: described current rectifying and wave filtering circuit is made up of rectifier diode D3 and capacitor C 3, the output of switching power circuit is connected LED module through rectifier diode D3 with capacitor C 3 successively.
5. a kind of LED constant-current supply with overheat protector as claimed in claim 1; it is characterized in that: described current feedback circuit comprises the resistance R 4 and the operational amplifier U1 that connect with LED module; the output of described operational amplifier U1 is connected in the input of pwm control circuit; the in-phase input end of described operational amplifier U1 is connected with reference voltage, and the inverting input of described operational amplifier U1 is connected in the common port of resistance R 4 and LED module.
6. a kind of LED constant-current supply with overheat protector as claimed in claim 1, is characterized in that: described temperature-detecting device is the PTC thermistor that is parallel to LED module.
7. a kind of LED constant-current supply with overheat protector as claimed in claim 1, is characterized in that: the power end of described pwm control circuit is connected in the output of input rectifying filter circuit by resistance R 3.
8. a kind of LED constant-current supply with overheat protector as claimed in claim 1, is characterized in that: described LED module is in series by multiple LED lamps, and each LED lamp respectively reverse parallel connection has Zener diode D4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320857640.5U CN203608439U (en) | 2013-12-24 | 2013-12-24 | LED constant current power supply with over-temperature protection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320857640.5U CN203608439U (en) | 2013-12-24 | 2013-12-24 | LED constant current power supply with over-temperature protection |
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| Publication Number | Publication Date |
|---|---|
| CN203608439U true CN203608439U (en) | 2014-05-21 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201320857640.5U Expired - Fee Related CN203608439U (en) | 2013-12-24 | 2013-12-24 | LED constant current power supply with over-temperature protection |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104023446A (en) * | 2014-06-16 | 2014-09-03 | 朱威 | Power source control device for indoor illuminating lamp |
| CN104302065A (en) * | 2014-10-31 | 2015-01-21 | 浙江大学 | LED driver with automatic temperature regulating and compensating function |
| CN105517227A (en) * | 2015-12-20 | 2016-04-20 | 合肥艾斯克光电科技有限责任公司 | LED lamp over-temperature protection method |
| CN104023446B (en) * | 2014-06-16 | 2016-11-30 | 朱威 | A kind of power control of indoor illumination |
| CN106793931A (en) * | 2014-10-10 | 2017-05-31 | 奥林巴斯株式会社 | Light supply apparatus |
| CN108988298A (en) * | 2018-08-29 | 2018-12-11 | 广州金升阳科技有限公司 | A kind of overtemperature and overcurrent protection circuit and the Switching Power Supply comprising the circuit |
| CN111885783A (en) * | 2020-07-30 | 2020-11-03 | 江苏博度信息科技有限公司 | Power supply device and lighting system |
-
2013
- 2013-12-24 CN CN201320857640.5U patent/CN203608439U/en not_active Expired - Fee Related
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104023446A (en) * | 2014-06-16 | 2014-09-03 | 朱威 | Power source control device for indoor illuminating lamp |
| CN104023446B (en) * | 2014-06-16 | 2016-11-30 | 朱威 | A kind of power control of indoor illumination |
| CN106793931A (en) * | 2014-10-10 | 2017-05-31 | 奥林巴斯株式会社 | Light supply apparatus |
| US10524646B2 (en) | 2014-10-10 | 2020-01-07 | Olympus Corporation | Light source apparatus |
| CN104302065A (en) * | 2014-10-31 | 2015-01-21 | 浙江大学 | LED driver with automatic temperature regulating and compensating function |
| CN104302065B (en) * | 2014-10-31 | 2016-08-17 | 浙江大学 | A kind of LED driver with autonomous temperature adjusting compensation function |
| CN105517227A (en) * | 2015-12-20 | 2016-04-20 | 合肥艾斯克光电科技有限责任公司 | LED lamp over-temperature protection method |
| CN108988298A (en) * | 2018-08-29 | 2018-12-11 | 广州金升阳科技有限公司 | A kind of overtemperature and overcurrent protection circuit and the Switching Power Supply comprising the circuit |
| CN111885783A (en) * | 2020-07-30 | 2020-11-03 | 江苏博度信息科技有限公司 | Power supply device and lighting system |
| CN111885783B (en) * | 2020-07-30 | 2022-11-15 | 华灯高节能技术(江苏)有限公司 | Power supply device and lighting system |
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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: 20140521 Termination date: 20141224 |
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| EXPY | Termination of patent right or utility model |