CN214473838U - LED lamp and flicker frequency detection circuit thereof - Google Patents
LED lamp and flicker frequency detection circuit thereof Download PDFInfo
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- CN214473838U CN214473838U CN202120510435.6U CN202120510435U CN214473838U CN 214473838 U CN214473838 U CN 214473838U CN 202120510435 U CN202120510435 U CN 202120510435U CN 214473838 U CN214473838 U CN 214473838U
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Abstract
The utility model discloses a LED lamp and a flicker frequency detection circuit thereof, the detection circuit comprises a light dependent resistor, the first end of the light dependent resistor is connected to the first input end of a voltage comparator, the second input end of the voltage comparator is connected to a reference voltage circuit, the first end of the light dependent resistor is also connected with a divider resistor, and the first input end of the voltage comparator is connected between the light dependent resistor and the divider resistor; the output end of the voltage comparator is electrically connected with the microcontroller and outputs a comparison result signal to the microcontroller. The LED lamp comprises an LED chip and the detection circuit. The utility model discloses the detection that can be accurate detects the flicker frequency of LED chip.
Description
Technical Field
The utility model relates to a LED lamps and lanterns field especially relates to a flicker frequency detection circuit of LED lamps and lanterns and have the LED lamps and lanterns of this kind of circuit.
Background
The LED lamp uses the LED chip as a light source, has the advantages of energy conservation, long service life and the like, and is widely applied to various lighting or indication scenes. For example, some LED lamps are used for illumination in daily work and life, while other LED lamps are used for indication, for example, indicating an operation state of a certain device, such as when an air conditioner is in an operation state, by driving the LED lamps on the housing to emit light, a user can know that the air conditioner is currently in the operation state.
Because the LED chip may flicker during operation, if the LED chip flickers frequently, the service life of the LED chip is affected, and the user may be dazzled, so that the flicker frequency of the LED lamp needs to be detected.
For this reason, the existing LED lamp is provided with a detection circuit for detecting a flicker frequency of the LED chip, the detection circuit is provided with an illumination sensor, and the illumination intensity of the LED chip is collected by the illumination sensor. Generally, a signal output by the illumination sensor is an analog signal, the analog signal is sent to the microcontroller, and the microcontroller determines the on-off state of the LED chip according to the magnitude of the analog signal after receiving the analog signal, so as to calculate the flicker frequency of the LED lamp.
However, since the analog signal output by the illumination sensor is easily affected by the surrounding environment, and the magnitude of the analog signal output by the illumination sensor is often related to the brightness of the LED chip, if the brightness of the LED chip is not high, the level of the analog signal output by the illumination sensor is not high and unstable, and the situation of false detection is easily caused. In addition, because the frequency of the signal output by the illumination sensor is not necessarily high, if the LED chip flashes frequently, the existing detection circuit is difficult to detect the high LED stroboscopic condition.
Disclosure of Invention
The utility model aims at providing a can accurate LED lamps and lanterns scintillation frequency detection circuitry who detects the LED lamps and lanterns scintillation condition.
A second object of the present invention is to provide an LED lamp with the above detection circuit.
In order to achieve the first objective, the utility model provides a LED lamp flicker frequency detection circuit includes a photo resistor, a first end of the photo resistor is connected to a first input end of a voltage comparator, a second input end of the voltage comparator is connected to a reference voltage circuit, a divider resistor is further connected to the first end of the photo resistor, and the first input end of the voltage comparator is connected between the photo resistor and the divider resistor; the output end of the voltage comparator is electrically connected with the microcontroller and outputs a comparison result signal to the microcontroller.
According to the scheme, the on-off state of the LED chip is detected through the photoresistor, for example, when the LED chip emits light, the resistance value of the photoresistor is smaller, and when the LED chip does not emit light, the resistance value of the photoresistor is larger, so that the voltage of the first input end of the voltage comparator is changed, and the output result of the voltage comparator is further changed. Because the output result of the voltage comparator only has a high level and a low level, the waveform is stable, and the condition of error detection caused by unstable output voltage waveform of the illumination sensor can be avoided.
Preferably, the reference voltage circuit comprises a reference voltage resistor, and preferably, the reference voltage resistor is an adjustable resistor, and the second input terminal of the voltage comparator is connected to the middle tap of the adjustable resistor.
Therefore, the reference voltage resistor is set to be the adjustable resistor, different resistance values can be set according to different LED chip powers, namely the reference voltage of the voltage comparator is changed, and the use requirements of different types of LED lamps are met.
The voltage comparator is characterized in that the output end of the voltage comparator is also provided with a filter circuit, and preferably, the filter circuit comprises a filter capacitor and a resistor which are connected in parallel.
Therefore, the voltage output by the voltage comparator is output to the microcontroller after being filtered, so that the voltage received by the microcontroller can be ensured to be stable, a large number of interference signals can not appear in the waveform of the voltage signal, and the detection accuracy is improved.
In order to achieve the second objective, the present invention provides an LED lamp including an LED chip and a detection circuit for detecting a flicker frequency of the LED chip, wherein the detection circuit includes a photo resistor, a first end of the photo resistor is connected to a first input end of a voltage comparator, a second input end of the voltage comparator is connected to a reference voltage circuit, a first end of the photo resistor is further connected to a divider resistor, and a first input end of the voltage comparator is connected between the photo resistor and the divider resistor; the output end of the voltage comparator is electrically connected with the microcontroller and outputs a comparison result signal to the microcontroller.
Drawings
Fig. 1 is an electrical schematic diagram of an embodiment of a flicker frequency detection circuit of an LED lamp and an LED chip.
The present invention will be further explained with reference to the drawings and examples.
Detailed Description
The utility model discloses a LED lamps and lanterns have the LED chip and are used for detecting the detection circuitry of LED chip flicker frequency, see fig. 1, and LED chip anode terminal is connected to DC power supply VCC, negative pole end ground connection. The detection circuit is provided with a photoresistor R2, the photoresistor R2 faces the LED chip, the resistance value of the photoresistor R2 is related to the brightness of the LED chip, when the brightness of the LED chip is high, the resistance value of the photoresistor R2 is low, and when the LED chip does not emit light or the brightness of the LED chip is low, the resistance value of the photoresistor R2 is high.
The photoresistor R2 is connected in series with divider resistor R1, and the first end of divider resistor R1 is connected to DC power supply VCC, and the second end of divider resistor is connected with the first end of photoresistor R2, and the second end ground of photoresistor R2.
The detection circuit is further provided with a voltage comparator U1, wherein the first input end of the voltage comparator U1 is a positive input end IN +, the first input end is connected to the connection point of the voltage-dividing resistor R1 and the photoresistor R2, namely the first input end is connected between the voltage-dividing resistor R1 and the photoresistor R2. The second input terminal of the voltage comparator U1 is an inverting input terminal IN-, and the second input terminal is connected to a reference voltage circuit, IN this embodiment, the reference voltage circuit includes a reference voltage resistor, preferably, the reference voltage resistor is an adjustable resistor R3, the adjustable resistor R3 has a middle tap, and the resistance value of the adjustable resistor R3 can be adjusted by changing the position of the middle tap.
The second input terminal of the voltage comparator U1 is connected to the center tap of the adjustable resistor R3, so that by adjusting the position of the center tap, the voltage at the second input terminal of the voltage comparator U1 can be varied. Because the voltage received by the second input end of the voltage comparator U1 is the reference voltage, the reference voltage can be adjusted by adjusting the position of the middle tap, so that the LED lamp can flexibly adapt to different types of LED lamps, namely the requirements of LED chips with different light-emitting brightness are met.
The output terminal of the voltage comparator U1 is electrically connected to the microcontroller U2, and outputs comparison result information to the microcontroller U2. When the voltage of the first input end of the voltage comparator U1 is greater than that of the second input end, the output end of the voltage comparator U1 outputs a high level signal, and when the voltage of the first input end of the voltage comparator U1 is less than that of the second input end, the output end of the voltage comparator U1 outputs a low level signal. Therefore, the microcontroller U2 will only receive a high signal or a low signal.
In order to improve the voltage waveform stability of the voltage signal output by the voltage comparator U1, a filter circuit is arranged at the output end of the voltage comparator U1 and comprises a filter capacitor C1 and a resistor R4 which are connected in parallel, the voltage signal output by the voltage comparator U1 passes through the filter circuit, the voltage waveform becomes smoother, the peak caused by interference signals is avoided, the signal received by the microcontroller U2 is smoother, and the detection on the flicker frequency of the LED chip is more accurate.
Before the flicker frequency of the LED chip is detected, firstly, the proper position of the middle tap of the adjustable resistor R3 is set according to the luminous brightness of the LED chip. When the LED chip emits light with a larger brightness and the photo resistor R2 has a smaller resistance, the voltage at the first input terminal of the voltage comparator U1 is lower than the voltage at the second input terminal, and the voltage comparator U1 outputs a low level signal. When the LED chip does not emit light or the light emitting brightness is small, the resistance of the photo resistor R2 is large, and therefore, the voltage at the first input end of the voltage comparator U1 is high, for example, higher than the voltage at the second input end, and at this time, the voltage comparator U1 outputs a high level signal.
Therefore, when the LED chip flickers, the LED chip will go through the processes of light-emitting-extinguishing-light-emitting, and the voltage signal outputted by the voltage comparator U1 goes through the processes of low level-high level-low level, i.e. a pulse signal is formed. Thus, the signal received by the microcontroller U2 is a pulsed signal. Thus, the microcontroller U2 can determine that a flash occurs on the LED chip when receiving a pulse signal.
The microcontroller U2 counts the number of pulse signals received over a period of time, for example, determines the number of pulse signals received in 1 minute, from which the frequency of flashing of the LED chip can be calculated.
Because the signal that microcontroller U2 received is not by the illumination sensor output, but by voltage comparator U1 output, the voltage signal that voltage comparator output U1 only has high level or low level, and the voltage waveform is stable, is favorable to microcontroller U2 accurate calculation LED chip's scintillation frequency, promptly calculates the scintillation frequency of LED lamps and lanterns.
Of course, the above-mentioned solution is only the preferred embodiment of the present invention, and the practical application may also have more changes, for example, two input ends of the voltage comparator may be connected in reverse, or the specific structure of the filter circuit may be adjusted as required, and these changes do not affect the implementation of the present invention, and should also be included in the protection scope of the present invention.
Claims (10)
- The flicker frequency detection circuit of the LED lamp is characterized by comprising:the first end of the photoresistor is connected to the first input end of the voltage comparator, the second input end of the voltage comparator is connected to the reference voltage circuit, the first end of the photoresistor is also connected to the divider resistor, and the first input end of the voltage comparator is connected between the photoresistor and the divider resistor;and the output end of the voltage comparator is electrically connected with the microcontroller and outputs a comparison result signal to the microcontroller.
- 2. The flicker frequency detection circuit of the LED lamp according to claim 1, wherein:the reference voltage circuit includes a reference voltage resistor.
- 3. The flicker frequency detection circuit of the LED lamp according to claim 2, wherein:the reference voltage resistor is an adjustable resistor, and a second input end of the voltage comparator is connected to a middle tap of the adjustable resistor.
- 4. The LED lamp flicker frequency detection circuit according to any one of claims 1 to 3, wherein:and the output end of the voltage comparator is also provided with a filter circuit.
- 5. The LED lamp flicker frequency detection circuit of claim 4, wherein:the filter circuit comprises a filter capacitor and a resistor which are connected in parallel.
- The LED lamp comprises an LED chip and a detection circuit for detecting the flicker frequency of the LED chip;characterized in that, this detection circuitry includes:the first end of the photoresistor is connected to the first input end of the voltage comparator, the second input end of the voltage comparator is connected to the reference voltage circuit, the first end of the photoresistor is also connected to the divider resistor, and the first input end of the voltage comparator is connected between the photoresistor and the divider resistor;and the output end of the voltage comparator is electrically connected with the microcontroller and outputs a comparison result signal to the microcontroller.
- 7. The LED lamp of claim 6, wherein:the reference voltage circuit includes a reference voltage resistor.
- 8. The LED light fixture of claim 7 wherein:the reference voltage resistor is an adjustable resistor, and a second input end of the voltage comparator is connected to a middle tap of the adjustable resistor.
- 9. The LED light fixture of any of claims 6-8 wherein:and the output end of the voltage comparator is also provided with a filter circuit.
- 10. The LED light fixture of claim 9 wherein:the filter circuit comprises a filter capacitor and a resistor which are connected in parallel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120510435.6U CN214473838U (en) | 2021-03-10 | 2021-03-10 | LED lamp and flicker frequency detection circuit thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120510435.6U CN214473838U (en) | 2021-03-10 | 2021-03-10 | LED lamp and flicker frequency detection circuit thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN214473838U true CN214473838U (en) | 2021-10-22 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202120510435.6U Active CN214473838U (en) | 2021-03-10 | 2021-03-10 | LED lamp and flicker frequency detection circuit thereof |
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| Country | Link |
|---|---|
| CN (1) | CN214473838U (en) |
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2021
- 2021-03-10 CN CN202120510435.6U patent/CN214473838U/en active Active
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| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of utility model: LED lamps and their flicker frequency detection circuit Effective date of registration: 20230330 Granted publication date: 20211022 Pledgee: Guangfa Bank Co.,Ltd. Zhuhai Jinwan Branch Pledgor: ZHUHAI CRYSTONE TECHNOLOGY Co.,Ltd. Registration number: Y2023980036691 |
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| PE01 | Entry into force of the registration of the contract for pledge of patent right | ||
| PC01 | Cancellation of the registration of the contract for pledge of patent right |
Granted publication date: 20211022 Pledgee: Guangfa Bank Co.,Ltd. Zhuhai Jinwan Branch Pledgor: ZHUHAI CRYSTONE TECHNOLOGY Co.,Ltd. Registration number: Y2023980036691 |
|
| PC01 | Cancellation of the registration of the contract for pledge of patent right |