CN207802465U - LED lamp and its power circuit - Google Patents
LED lamp and its power circuit Download PDFInfo
- Publication number
- CN207802465U CN207802465U CN201820137739.0U CN201820137739U CN207802465U CN 207802465 U CN207802465 U CN 207802465U CN 201820137739 U CN201820137739 U CN 201820137739U CN 207802465 U CN207802465 U CN 207802465U
- Authority
- CN
- China
- Prior art keywords
- temperature
- coefficient thermistor
- circuit
- value
- led
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Circuit Arrangement For Electric Light Sources In General (AREA)
- Led Devices (AREA)
Abstract
The utility model provides a kind of LED lamp and its power circuit, which includes driving chip, and driving chip is to LED luminescence chip output currents；It further include temperature-control circuit, the output end of temperature-control circuit exports analog voltage signal to the light modulation pin of driving chip, wherein, temperature-control circuit includes the posive temperature coefficient thermistor and negative tempperature coefficient thermistor being connected in series with, the first end of posive temperature coefficient thermistor is high level end, the second end of posive temperature coefficient thermistor and the first end of negative tempperature coefficient thermistor connect, negative tempperature coefficient thermistor second end is low level end, and output end is connected to the second end of posive temperature coefficient thermistor.The LED lamp has above-mentioned power circuit and LED luminescence chips.The utility model can effectively control the temperature of LED lamp within the scope of default temperature, avoid the heat-dissipating casing temperature of LED luminescence chips and LED lamp excessively high, and can improve the actual power of LED lamp.
Description
Technical field
The utility model is related to field of LED illumination；More specifically, be related to a kind of LED lamp that automobile uses and
The power circuit that this LED lamp uses.
Background technology
Currently, the car light of automobile generally uses halogen lamp or LED car lamp.Since LED luminescence chips have low-power, height
The application of the advantages that light emission luminance, long life, LED car lamp are more and more common.But due to that can be produced when LED luminescence chips work
Raw amount of heat will lead to the accumulation of heat and influence the normal works of LED luminescence chips if these heats guide not in time
Make, generates serious light decay, even result in burning for LED luminescence chips.Therefore, existing LED car lamp is required to setting radiator,
Heat caused by LED luminescence chips to be guided in time.
However, if only radiator is arranged, although the heat that LED luminescence chips generate can be guided, LED vehicles
Temperature in lamp can still can exceed that the maximum temperature that LED luminescence chips can be born, serious there are still making LED luminescence chips occur
The risk that light decay is even burnt.Therefore, existing LED car lamp needs that temperature protection circuit is arranged on its power circuit, to avoid
LED luminescence chips are among hot environment.
The power circuit of existing LED car lamp includes driving circuit and temperature protection circuit, wherein driving circuit is set
It is equipped with driving chip, driving chip is to LED luminescence chips output current to drive LED luminescence chips to work.Temperature protection circuit
It is usually provided with a thermistor, such as a posive temperature coefficient thermistor is set in LED circuit board, works as LED circuit
When the temperature of plate increases, the resistance value of posive temperature coefficient thermistor also increases, and stream is reduced using the partial pressure of thermistor
Electric current through LED luminescence chips, and then reduce heat caused by LED luminescence chips, or even directly shutdown flows through the luminous cores of LED
The electric current of piece.
But since existing LED car lamp is all made of single thermistor, such as positive temperature coefficient is only used only
The resistance value of thermistor, single thermistor varies with temperature often not enough greatly, and the power and luminous flux of LED car lamp are relatively
It is low, if the power of LED car lamp itself exceeds the range that can bear of its radiator, when LED car lamp ambient temperature not
When identical, such as areal differs greatly in summer and winter temperature, or temperature is also different all over the world, at this time often
Be difficult to ensure that the temperature of LED car lamp is maintained at safe value range, for example, the radiator of LED car lamp temperature be maintained at 75 DEG C with
It is interior.If LED car lamp internal temperature is excessively high, driving circuit may directly close electric current, influence the use of LED car lamp.
Invention content
First purpose of the utility model, which is to provide one kind, changing radiator (such as its shape, size and material
Matter) under conditions of and increase the actual power of LED lamp to substantially increase the power circuit of luminous flux.
Second purpose of the utility model, which is to provide one kind, effective protection LED to shine under conditions of not cutting off electric current
The power circuit that the LED lamp that chip is not burned uses.
The third purpose of the utility model is to provide one kind can effectively increase lamps and lanterns reality under conditions of not changing radiator
Border power and luminous flux, and can ensure that the temperature of LED luminescence chips will not mistake in varying environment and do not cut off electric current under conditions of
High LED lamp.
In order to realize that first and second above-mentioned purpose, the power circuit of LED lamp provided by the utility model include：
Driving circuit, driving circuit have driving chip, and driving chip is to LED luminescence chip output currents；
The output end of temperature-control circuit, temperature-control circuit is believed to the light modulation pin of driving chip output analog voltage
Number；Wherein, temperature-control circuit includes the posive temperature coefficient thermistor and negative tempperature coefficient thermistor being connected in series with, just
The first end of temperature coefficient thermistor is high level end, the second end and negative temperature coefficient heat-sensitive of posive temperature coefficient thermistor
The first end of resistance connects, and negative tempperature coefficient thermistor second end is low level end, and output end is connected to positive temperature coefficient heat
The second end of quick resistance.
A kind of preferred embodiment according to the present utility model, under the first preset temperature value, posive temperature coefficient thermistor
Resistance value is more than the resistance value of negative tempperature coefficient thermistor, and the voltage value that temperature-control circuit is exported to driving chip is critical voltage
Value.
It is highly preferred that when rising to third preset temperature value from the second preset temperature value, posive temperature coefficient thermistor
The resistance value that resistance value increment absolute value is more than negative tempperature coefficient thermistor is reduced absolute value.Wherein, the second preset temperature value can be with
Equal to or more than the first preset temperature value.
Another preferred embodiment according to the present utility model, temperature-control circuit further include debugging resistance, debugging resistance connection
Between the first end and DC power supply of posive temperature coefficient thermistor.
As a kind of specific implementation mode of the utility model, temperature-control circuit further includes voltage stabilizing chip, voltage stabilizing chip
Preset stable DC voltage is provided for temperature-control circuit.
As another specific implementation mode of the utility model, driving circuit is provided with booster circuit or reduction voltage circuit,
Driving chip is arranged in the booster circuit or reduction voltage circuit.
For the third purpose for realizing above-mentioned, LED lamp provided by the utility model includes LED luminescence chips and power supply electricity
Road, power circuit include：
Driving circuit, driving circuit have driving chip, and driving chip is to LED luminescence chip output currents；Wherein, it drives
Circuit can be provided with booster circuit or reduction voltage circuit, and driving chip is arranged in the booster circuit or reduction voltage circuit；
Temperature-control circuit, the light modulation pin output voltage signal of the output end of temperature-control circuit to driving chip；Its
In, temperature-control circuit includes the posive temperature coefficient thermistor and negative tempperature coefficient thermistor being connected in series with, positive temperature
The first end of coefficient resistance is high level end, the second end and negative tempperature coefficient thermistor of posive temperature coefficient thermistor
First end connection, negative tempperature coefficient thermistor second end is low level end, and output end is connected to positive temperature coefficient temperature-sensitive electricity
The second end of resistance.
In the utility model LED lamp, it is preferable that under the first preset temperature value, the resistance of posive temperature coefficient thermistor
For value more than the resistance value of negative tempperature coefficient thermistor, the voltage value that temperature-control circuit is exported to driving chip is critical voltage
Value；It is highly preferred that when rising to third preset temperature value from the second preset temperature value, the resistance value of posive temperature coefficient thermistor increases
Measure the resistance value decrement absolute value that absolute value is more than negative tempperature coefficient thermistor.Wherein, the second preset temperature value can be equal to or
Person is more than the first preset temperature value.
In above-mentioned LED lamp, the device and LED luminescence chips of power circuit can be arranged in such as aluminium base or copper-based
Metal base printed circuit board first surface side on, the second surface side of metal base printed circuit board is thermally connected with radiator.
Wherein, the second side surface of metal base printed circuit board can be coated with heat-conducting silicone grease, and heat-conducting silicone grease is close to radiator；Alternatively,
It is provided with heat-conducting pad between the second side surface of metal base printed circuit board and radiator.
In a kind of specific implementation mode of above-mentioned LED lamp, it is provided with fixing groove on radiator, is equipped in fixing groove solid
Determine part, fixed seat is arranged outside fixing groove, and fixed seat is fixedly connected with fixing piece.
In power circuit used in LED lamp provided by the utility model, the driving chip of driving circuit receives temperature
The voltage signal for spending control circuit output controls the electric current that driving chip is exported to LED luminescence chips by temperature-control circuit
Size, to control the power of LED luminescence chips, to control the temperature of LED luminescence chips.Also, temperature-control circuit is arranged
There is the thermistor of the posive temperature coefficient thermistor and negative temperature coefficient that are connected in series with, when the temperature is changed, such as temperature
When raising, the resistance value of posive temperature coefficient thermistor increases, and the resistance value of negative tempperature coefficient thermistor reduces, two temperature-sensitive electricity
The voltage change of resistance is very big, in this way, the voltage change that temperature-control circuit is exported to driving chip is also very big, so that load
Curent change on LED luminescence chips is very big.When the temperature increases, electric current of the load on LED luminescence chips is reduced rapidly,
So as under conditions of not cutting off electric current reduce LED luminescence chips caused by heat, when temperature reach the first preset value with
Afterwards, temperature increases more, and electric current then declines more, the calorific value of LED luminescence chips namely declines more, and electric current
Fall can also increase with the raising of temperature, finally make temperature control within desired range, such as 75 DEG C, in turn
It realizes and purpose is adjusted to the temperature of LED luminescence chips.Also, in different environments, it is up to different equalization points.
Electric current of the load on LED luminescence chips will be reduced rapidly when being increased due to LED luminescence chip temperature, can be with
Effectively avoid the temperature of LED luminescence chips excessively high.Compared with prior art, ensuring LED luminescence chips not higher than mutually synthermal
And not change radiator in the case of, after the embodiment of the utility model, higher work(can be integrated on same circuit board
The LED luminescence chips of rate improve the luminous flux and brightness of illumination of LED lamp.
Further, after due to being increased in temperature, the change in resistance of the thermistor of positive temperature coefficient is more than negative temperature
The change in resistance of the thermistor of coefficient, so that the electric current reduction for being loaded into LED luminescence chips is more obvious, it is more efficient
Reduction LED luminescence chips caused by heat, to avoid the temperature of LED luminescence chips excessively high.
In addition, the electricity that voltage stabilizing chip can ensure the first end of posive temperature coefficient thermistor is arranged on temperature-control circuit
Pressure is stablized, so that it is guaranteed that temperature-control circuit can be accurately controlled the voltage exported to driving chip, accurately controls LED
The temperature of luminescence chip.
Also, the device of power circuit, including two thermistors are arranged with LED luminescence chips in Metal Substrate printing electricity
On the same face of road plate, it is more conducive to the resistance value that thermistor changes resistance according to the temperature of LED luminescence chips in real time, to
So that the voltage change that is exported to driving chip of temperature-control circuit is in real time according to the temperature change of LED luminescence chips, to
The accurate temperature for adjusting LED luminescence chips.
Hereinafter, in conjunction with accompanying drawings and embodiments, the utility model is described in further detail.
Description of the drawings
Fig. 1 is the structure chart of the utility model LED lamp embodiment；
Fig. 2 is the structural exploded view of the utility model LED lamp embodiment；
Radiator and fixing piece, the structural exploded view of fixed seat in Fig. 3 the utility model LED lamp embodiments；
Fig. 4 is the electrical schematic diagram of the power circuit embodiment of the utility model LED lamp；
Fig. 5 is the temperature resistance value curve graph of posive temperature coefficient thermistor；
Fig. 6 is the temperature resistance value curve graph of negative tempperature coefficient thermistor.
Specific implementation mode
LED lamp embodiment：
The present embodiment LED lamp can be mounted in the car light on automobile, such as mounted on the headlamp of automobile head, or
Person is the steering indicating light of automobile.
Referring to Fig. 1, the present embodiment LED lamp 10 has radiator 11, and is set respectively in the transverse ends of radiator 11
It is equipped with fixation kit 20.Referring to Fig. 2, the side of radiator 11 is provided with one piece of light-transmitting plate 30, and in light-transmitting plate 30 and dissipate
One piece of aluminum-base printing circuit board 35 is provided between hot device 11；Multiple LED are provided on the first surface side of circuit board 35 to shine
The device of chip and power circuit, power circuit can power to LED luminescence chips, to provide LED luminescence chips luminous institute
The electric energy needed；Second side surface of circuit board 35 is coated with heat-conducting silicone grease, and heat-conducting silicone grease is close to radiator 11, to realize circuit
The thermal connection of plate 35 and radiator 11.Multiple light cups 31 are provided between circuit board 35 and light-transmitting plate 30, each LED shines
Chip is located at the bottom of a light cup 31, and the light that LED luminescence chips are sent out is then passed through light-transmitting plate after the reflection of light cup 31
30.In the utility model, LED luminescence chips directly can encapsulate (chip on board encapsulation) on circuit boards by COB, or with welding
The form of LED lamp bead on circuit boards provides.
In the present embodiment, the device and LED luminescence chips of power circuit are arranged on the same side of circuit board 35,
It is exactly arranged far from the side of radiator 11.Due to being provided with thermistor on power circuit, LED luminescence chips with
Thermistor is located on the same side of circuit board 35, and heat caused by LED luminescence chips will be conducted to thermistor in time.
End cap there are one being respectively set on the outside of longitudinal both ends of radiator 11, is end cap 40 and end cap 41, end cap respectively
40 are fastened on the both ends of light-transmitting plate 30, circuit board 35 and radiator 11 with end cap 41, to by light-transmitting plate 30, circuit board 35 with
And radiator 11 is fixed.Also, electric wire 42 is additionally provided on end cap 40, external electric current flows through circuit board 35 by electric wire 42
Power circuit on.
Referring to Fig. 3, the side in the outside of radiator 11, that is, far from circuit board 35 is provided with multi-disc fin 12, LED
It after heat caused by luminescence chip is conducted to radiator 11, can be radiated by fin 12, due to fin 12 and sky
The contact area of gas is larger, therefore can quickly conduct heat to air, to quickly realize dissipating for LED luminescence chips
Heat.
Each fixation kit 20 of the present embodiment includes fixing piece 16 and fixed seat 21, in the lower end of radiator 11
It is provided with the fixing groove 13 of a strip, the upper surface of 13 inside of fixing groove is both provided with rack 15, fixing piece with lower surface
16 are also equipped with rack on the surface in outside, after fixing piece 16 is installed to fixing groove 13, the rack of fixing piece 16 with it is solid
Determine the rack engagement in slot 13.
Fixed seat 21 is mounted on outside fixing groove 13, also, there are one through-holes 22 for setting on a wall of fixed seat 21, fixed
The middle part of part 16 is provided with threaded hole, and screw 25 passes through through-hole 22 and screws in the threaded hole of fixing piece 16, to realize fixation
Fixation between seat 21 and fixing piece 16.In addition, fixed seat 21 is provided with arc opening 23, arc close to the side of fixing piece 16
It is also equipped with rack on the surface of opening 23；The upper surface in 13 outside of fixing groove is both provided with rack 14, rack 14 with lower surface
It can be engaged with the rack on arc opening 23.
Through-hole is also equipped on another wall of fixed seat 21, screw 26 passes through the through-hole and by 21 bolt of fixed seat in vapour
On the mounting plate of vehicle, to realize the fixation between LED lamp and automobile mounting plate.
LED lamp power circuit embodiment：
The power circuit embodiment of LED lamp is introduced with reference to Fig. 4.The power circuit of the present embodiment includes driving circuit
51 and temperature-control circuit 52, wherein driving circuit 51 includes reverse-connection preventing circuit, input rectifying filter circuit, further include by
Decompression (BUCK) circuit of driving chip U1, energy storage inductor L1, sustained diode 1, D2 and field-effect tube Q1 compositions.Wherein,
Reverse-connection preventing circuit includes counnter attack connecting resistance R6, zener diode ZD1 and field-effect tube Q2, and effect is prevented direct current accidentally
Driving chip U1 is burnt out when the positive and negative anodes reversal connection of source.When by DC power supply positive and negative anodes reversal connection, since field-effect tube Q2 is not turned on, electricity
Stream does not flow through driving chip U1, therefore driving chip U1 can be protected not to be burned.The positive and negative anodes of only DC power supply are correct
After connection, field-effect tube Q2 can just be connected.
Input rectifying filter circuit is arranged in the rear end of counnter attack connecting resistance R6, and input rectifying filter circuit includes parallel with one another
Transient state to resist diode TVS and filter capacitor, the effect of the filter capacitor be the voltage waveform smoothly inputted, the TVS's
Effect is to prevent surge voltage from burning out driving chip U1 and field-effect tube Q1.In this way, the DC voltage of input passes through after being rectified
Reduction voltage circuit is to the stable electric current Io of multiple LED luminescence chips output, in the present embodiment, the setting value of electric current Io by resistance R1,
The equivalent resistance R of R2, R3 parallel connection is determined.
Fig. 4 shows six LED luminescence chips, is LED1 to LED6 respectively, and six LED luminescence chips are divided into two groups,
Wherein LED luminescence chips LED1, LED3, LED5 are connected in series with, and LED luminescence chips LED2, LED4, LED6 are connected in series with, two groups
LED luminescence chips are connected in parallel.Certainly, in actual use, the quantity of LED luminescence chips can be set according to actual needs, and
And the connection relation of the multiple LED luminescence chips of setting.
The output voltage of driving circuit is filtered by filter capacitor C2, it is ensured that the electricity that LED luminescence chips receive
Corrugating is more smooth.
The 3rd pin of driving chip U1 is light modulation pin, and light modulation pin is connected to temperature-control circuit 52 and receives temperature
The analog voltage signal that control circuit 52 exports, in the present embodiment, temperature-control circuit 52 includes voltage stabilizing chip U2, voltage stabilizing core
The voltage input end of piece U2 is connected to DC power supply terminal VIN by resistance R4 and rectifier diode D5 and receives externally input
DC voltage.
In the reduction voltage circuit of the present embodiment, two sustained diodes 1, D2 are connected in parallel, the 5th pin of driving chip U1
It is connected to the grid of field-effect tube Q1, when field-effect tube Q1 is connected, inductance L1 energy storage；When field-effect tube Q1 ends, inductance
L1 discharges to capacitance C2, to maintain the voltage stabilization exported to LED luminescence chips.Certainly, the present embodiment is in the driving circuit
Reduction voltage circuit is set, when practical application, boosting (BOOST) circuit replacement reduction voltage circuit can also be designed, this can equally reach
Identical effect.
The voltage output end of voltage stabilizing chip U2 is connected with filter capacitor C4, and is also associated with bleeder circuit, the present embodiment
Bleeder circuit includes debugging resistance R5, posive temperature coefficient thermistor PTC and the negative temperature coefficient heat-sensitive being sequentially connected in series
Resistance NTC, wherein debugging resistance R5 is connected between the first end and DC power supply of posive temperature coefficient thermistor PTC.This reality
It applies in example, DC power supply can be constant-current source, such as provide the DC power supply of the burning voltage of 9V.
Since posive temperature coefficient thermistor PTC and negative tempperature coefficient thermistor NTC are connected in series with, also, positive temperature
The first end of coefficient resistance PTC is connected to DC power supply by debugging resistance R5, and the of posive temperature coefficient thermistor PTC
Two ends are connect with the first end of negative tempperature coefficient thermistor NTC, and the second end of negative tempperature coefficient thermistor NTC is grounded,
Therefore, the first end of posive temperature coefficient thermistor PTC is high level end, and negative tempperature coefficient thermistor NTC second ends are low
Level terminal, the connection between the second end and the first end of negative tempperature coefficient thermistor NTC of posive temperature coefficient thermistor PTC
Point is the output end of temperature-control circuit 52, and the 3rd pin of driving chip U1 is connected to by resistance RD1.
In the present embodiment, the 3rd pin of driving chip U1 is light modulation pin, such as when the 3rd pin of driving chip U1
Voltage is in 2.5V or less and in 0.7V or more, and driving circuit 51 will enter analog dimming mode, due to driving chip U1's
3rd pin is connected with the ADJ of temperature-control circuit 52 points, therefore can be loaded into the voltage of ADJ points by control to control
Whether driving chip U1 enters light-modulating mode.
Under light-modulating mode, the electric current I being loaded on LED luminescence chips is calculated approximately by formula 1,
I ≈ Io × Vadj/2.5V (formula 1)
In formula 1, Io is the setting electric current of of driving circuit 51 itself, such as Io=U/R, and wherein U is that LED drives adopting for IC
Sample voltage, when driving IC used is PT4121, then U=0.2V, R are the equivalent resistances after resistance R1, R3, R3 series connection.Cause
This can extrapolate the voltage value Vadj of ADJ points, as shown in formula 2 according to formula 1.
Vadj=9V × NTC/ (R5+PTC+NTC) (formula 2)
In formula 2, R5 is the resistance value for debugging resistance R5, and PTC and NTC are posive temperature coefficient thermistor and subzero temperature respectively
Spend the resistance value of coefficient resistance.Due to debugging resistance R5 resistance value be it is constant, i.e., not variation with temperature and change, but
It is that the resistance value of posive temperature coefficient thermistor PTC increases with the raising of temperature, as shown in figure 5, when temperature rises to from 65 DEG C
At 75 DEG C, the resistance value of posive temperature coefficient thermistor PTC rises to the Europe 100K from the Europe 8K.Opposite, negative temperature coefficient thermistor power
The resistance value of resistance NTC declines with the raising of temperature, as shown in fig. 6, when temperature is from when rising to 75 DEG C for 65 DEG C, negative temperature coefficient is warm
The resistance value of quick resistance NTC drops to Europe 3K or so from the Europe 4.28K.
In the present embodiment, debugging resistance R5 is common Chip-R, for debugging temperature protection point.For example, can will adjust
The resistance value of examination resistance R5 is set as the Europe 3K, in this way, after LED luminescence chips work and generate heat, in positive temperature coefficient heat
When the temperature on quick resistance PTC and the peripheries negative tempperature coefficient thermistor NTC is increased to 65 DEG C, due to positive temperature coefficient temperature-sensitive electricity
The resistance value of PTC is hindered about in the Europe 8K, and the resistance value of negative tempperature coefficient thermistor NTC is in Europe 4.28K or so, at this time according to formula
The 2 voltage Vadj that can calculate ADJ points are about 2.5V, and driving circuit 51 enters analog dimming mode, at this time on circuit board
Temperature often increase once, the voltage of ADJ points all can drastically become smaller, so that the electric current that is loaded on LED luminescence chips is anxious
Reduce sharply it is small, to reduce heat caused by LED luminescence chips.
For example, when temperature is increased to 70 DEG C, the resistance value of posive temperature coefficient thermistor PTC is about in the Europe 30K, and subzero temperature
The resistance value of coefficient resistance NTC is spent in Europe 3.57K or so, can be calculated according to formula 1 be loaded into LED luminescence chips at this time
On electric current I be about I=Io × 0.9/2.5=Io × 36%.Continue to increase with temperature, when temperature is increased to 75 DEG C
When, the resistance value of posive temperature coefficient thermistor PTC is about in the Europe 100K, and the resistance value of negative tempperature coefficient thermistor NTC is in 3K
Europe or so, it is about I=Io × 0.25/2.5 that can calculate the electric current I being loaded on LED luminescence chips according to formula 1 at this time
=Io × 10%.
As it can be seen that when temperature rise is to after 65 DEG C, driving circuit 51 will enter light-modulating mode, and with the liter of temperature
The electric current of height, driving chip U1 outputs will strongly reduce, and due to the presence of regulator circuit, be loaded into the voltage of LED luminescence chips
It is constant, therefore, after the electric current being loaded on LED luminescence chips reduces, the power of LED luminescence chips also accordingly reduces,
Generated heat also accordingly reduces, and effectively avoids the temperature of LED luminescence chips excessively high so that the temperature of LED luminescence chips can
To control between so that circuit board temperature is maintained at 65 DEG C to 75 DEG C.
Therefore, by selecting the debugging resistance R5 of suitable resistance value, and the suitable positive temperature coefficient temperature-sensitive electricity of selected parameter
PTC, negative tempperature coefficient thermistor NTC are hindered, can be made under the first preset temperature value, such as at 65 DEG C, temperature control electricity
The voltage value that road 52 is exported to driving chip U1 is critical voltage value, the i.e. voltage signal of 2.5V so that driving circuit 51 enters
Light-modulating mode.Also, when rising to third preset temperature value from the second preset temperature value, such as from when rising to 75 DEG C for 70 DEG C,
Resistance value decrement of the resistance value increment absolute value of posive temperature coefficient thermistor PTC more than negative tempperature coefficient thermistor NTC is absolute
Value, in this way so that during the second preset temperature value rises to third preset temperature value, be loaded into LED luminescence chips
Electric current strongly reduces.
It, can dissipating in identical radiator after the embodiment of the utility model compared to previous power circuit is played
Under thermal energy power, increases the quantity or power of LED luminescence chips, that is, the power of LED lamp is done more, it therefore, can be with
It is not modifying to the mold of existing LED lamp, is not also increasing the volume and heat dissipation area of radiator, as long as to circuit board
On power circuit be adjusted, you can the power designs of LED lamp are obtained bigger.When vehicle in the process of moving, due to
Wind speed is larger, better heat-radiation effect, and the radiator shell temperature for being mounted on the LED lamp of rear of vehicle is lower, correspondingly, circuit
The temperature of plate is relatively low, then the electric current that driving chip U1 is exported is higher so that LED lamp can obtain very high luminous flux.
Therefore, the LED lamp of the utility model is adapted to each regional temperature in the whole world, and may insure the circuit board in LED lamp
Temperature within 75 DEG C.
One specific example is, using the existing LED car lamp of above-mentioned radiator, the power of LED car lamp can only at most be set
It is set to 50W, luminous flux only has 4300 lumens or so, this is because the heat-sinking capability of radiator is limited, if by the work(of LED car lamp
Rate is designed higher, and circuit board temperature will be more than 70 DEG C.It, can be in heat spreader structures after using the embodiment of the utility model
It is 100W by the power designs of LED luminescence chips, luminous flux reaches 7100 lumens, and use is American-European non-in the case of constant
When the different zones such as continent, during traveling, due to the relationship of wind speed, the heat dissipation performance of radiator is fine, the temperature of radiator
Very low, the temperature of circuit board is also very low, and LED car lamp will be in highest full power operation state at this time, and luminous flux is maximum.And work as vehicle
When stopping, when radiating bad, temperature-control circuit plays a role immediately, so that the power of LED luminescence chips is declined, environment temperature
Degree it is higher, then the electric current for being loaded into LED luminescence chips declines bigger, to make the temperature on circuit board be maintained at 75 DEG C with
It is interior, to protect LED luminescence chips and internal circuit.
In addition, the temperature-control circuit 52 in the utility model is to control driving circuit 51 by exporting analog voltage
Work is loaded into LED luminescence chips to realize to the current regulation of LED luminescence chips compared to being adjusted using pwm signal
Average current technology, the embodiment of the utility model enter temp-controled mode when, possess higher light efficiency, and will not go out
It now utters long and high-pitched sounds the phenomenon that being flickered with LED luminescence chips.
It is readily appreciated that, although being particularly suitable for LED car lamp, the power circuit of utility model can also be applied to for example
Other various LED lamps of LED street lamp, LED ships lamp, LED stage lamp etc..
Although depicting the utility model above by preferred embodiment, but it is to be understood that, ordinary skill
Personnel are all according to being improved on an equal basis made by the utility model in the invention scope for not departing from the utility model, as LED shines core
The change of piece quantity, the variations such as change of selected posive temperature coefficient thermistor, negative tempperature coefficient thermistor model, are answered
Covered by the scope of protection of the utility model.
Claims (10)
1. a kind of power circuit of LED lamp, including：
Driving circuit, the driving circuit have driving chip, and the driving chip is to LED luminescence chip output currents；
The output end of temperature-control circuit, the temperature-control circuit exports analog voltage to the light modulation pin of the driving chip
Signal；
It is characterized in that：The temperature-control circuit includes the posive temperature coefficient thermistor and negative temperature coefficient being connected in series with
Thermistor, the first end of the posive temperature coefficient thermistor are high level end, the of the posive temperature coefficient thermistor
Two ends are connect with the first end of the negative tempperature coefficient thermistor, and the negative tempperature coefficient thermistor second end is low level
End, the output end are connected to the second end of the posive temperature coefficient thermistor.
2. power circuit according to claim 1, it is characterised in that：Under the first preset temperature value, the positive temperature system
The resistance value of number thermistors is more than the resistance value of the negative tempperature coefficient thermistor, and the temperature-control circuit is to the driving core
The voltage value of piece output is critical voltage value.
3. power circuit according to claim 2, it is characterised in that：The default temperature of third is risen to from the second preset temperature value
When angle value, the resistance value increment absolute value of the posive temperature coefficient thermistor is more than the resistance value of the negative tempperature coefficient thermistor
It is reduced absolute value.
4. power circuit according to any one of claims 1 to 3, it is characterised in that：The temperature-control circuit further includes
Resistance is debugged, the debugging resistance is connected between the first end and DC power supply of the posive temperature coefficient thermistor.
5. power circuit according to claim 4, it is characterised in that：The temperature-control circuit further includes voltage stabilizing chip,
The voltage output pin of the voltage stabilizing chip is connect with the DC power supply.
6. power circuit according to any one of claims 1 to 3, it is characterised in that：The driving circuit is provided with boosting
Either the reduction voltage circuit driving chip is arranged in the booster circuit or the reduction voltage circuit circuit.
7. a kind of LED lamp, including LED luminescence chips and power circuit, the power circuit include：
Driving circuit, the driving circuit have driving chip, and the driving chip is to the LED luminescence chips output current；
The output end of temperature-control circuit, the temperature-control circuit exports analog voltage to the light modulation pin of the driving chip
Signal；
It is characterized in that：The temperature-control circuit includes the posive temperature coefficient thermistor and negative temperature coefficient being connected in series with
Thermistor, the first end of the posive temperature coefficient thermistor are high level end, the of the posive temperature coefficient thermistor
Two ends are connect with the first end of the negative tempperature coefficient thermistor, and the negative tempperature coefficient thermistor second end is low level
End, the output end are connected to the second end of the posive temperature coefficient thermistor.
8. LED lamp according to claim 7, it is characterised in that：Under the first preset temperature value, the positive temperature coefficient
The resistance value of thermistor is more than the resistance value of the negative tempperature coefficient thermistor, and the temperature-control circuit is to the driving chip
The voltage value of output is critical voltage value.
9. LED lamp according to claim 8, it is characterised in that：The default temperature of third is risen to from the second preset temperature value
When angle value, the resistance value increment absolute value of the posive temperature coefficient thermistor is more than the resistance value of the negative tempperature coefficient thermistor
It is reduced absolute value.
10. LED lamp according to any one of claims 7 to 9, it is characterised in that：The device of the power circuit and
The LED luminescence chips are arranged on the first surface side of metal base printed circuit board, and the of the metal base printed circuit board
Two surface sides are thermally connected with radiator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820137739.0U CN207802465U (en) | 2018-01-26 | 2018-01-26 | LED lamp and its power circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820137739.0U CN207802465U (en) | 2018-01-26 | 2018-01-26 | LED lamp and its power circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207802465U true CN207802465U (en) | 2018-08-31 |
Family
ID=63270948
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201820137739.0U Active CN207802465U (en) | 2018-01-26 | 2018-01-26 | LED lamp and its power circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN207802465U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108112135A (en) * | 2018-01-26 | 2018-06-01 | 广州汗马电子科技有限公司 | LED lamp and its power circuit |
| CN114848929A (en) * | 2022-04-25 | 2022-08-05 | 广州华一生物科技有限公司 | Novel negative pressure wound therapeutic instrument |
-
2018
- 2018-01-26 CN CN201820137739.0U patent/CN207802465U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108112135A (en) * | 2018-01-26 | 2018-06-01 | 广州汗马电子科技有限公司 | LED lamp and its power circuit |
| CN114848929A (en) * | 2022-04-25 | 2022-08-05 | 广州华一生物科技有限公司 | Novel negative pressure wound therapeutic instrument |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1521503B1 (en) | Method and drive circuit for controlling leds | |
| US8282250B1 (en) | Solid state lighting device using heat channels in a housing | |
| US9622316B2 (en) | Light emitting diode replacement lamp | |
| CA2710542C (en) | Led lamp replacement of low power incandescent lamp | |
| EP2768286B1 (en) | Lighting device and lighting fixture | |
| EP2768281B1 (en) | Lighting device and lighting fixture | |
| JP2012520562A (en) | LED lighting device with color temperature behavior of incandescent lamp | |
| US9726362B2 (en) | LED heater system and method | |
| CN207802465U (en) | LED lamp and its power circuit | |
| JP2010015887A (en) | Led lighting control circuit and vehicle lamp fixture equipped with this | |
| CN108112135A (en) | LED lamp and its power circuit | |
| Long et al. | An intelligent driver for light emitting diode street lighting | |
| CN1605794A (en) | LED spot light | |
| CN2849473Y (en) | LED projecting lamp | |
| JP2012009369A (en) | Led bulb | |
| CN210579363U (en) | Silicon controlled rectifier dimming circuit | |
| CN220235012U (en) | LED light source driving circuit | |
| CN215121397U (en) | LED dimming power supply with stable work | |
| CN216565676U (en) | Front lamp circuit with temperature monitoring function, circuit board and front lamp | |
| CN210781467U (en) | Segmented control dimming circuit | |
| CN220273905U (en) | Drive control circuit and light emitting device | |
| CN210579340U (en) | Easy-to-expand silicon controlled rectifier dimming circuit | |
| JP2011003516A (en) | Structure for led luminaire | |
| CN207146073U (en) | A kind of MR16 intelligent dimmings shot-light | |
| CN206093602U (en) | LED (Light emitting diode) lamp tube |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |