A kind of anti-dazzle driving mirror driving circuit of adjustable transparencyTechnical field
The present invention relates to vehicular rear mirror driving circuit technical field, in particular to a kind of adjustable transparency it is anti-dazzleMesh rearview mirror driving circuit.
Background technique
The maximum security risk of driving at night is line-of-sight problems, be on the one hand because of darkness insufficient light, on the other hand becauseFor respectively always the headlight of vehicle influences traffic safety, if rear car driver opens high beam driving for a long time, rearview mirror is directly anti-by strong lightEye is injected, discomfort glare directly affects the sight of driver, further affects traffic safety, therefore it is anti-to introduce rearview mirrorDazzle the eyes function.Anti-dazzle driving mirror can be divided into inside rear-view mirror anti-glare and outside rear-view mirror anti-glare according to its distributing position；It can alsoAccording to its abblendbar mode, it is divided into manual anti-glare and automatic anti-glare.
Automatic anti-glare rearview mirror is mounted on photodiode, two photodiode difference under mirror surface and after mirror surfaceLight after receiving Chinese herbaceous peony and vehicle, if the headlamp of rear car is irradiated in rearview mirror, the light after rearview mirror vehicle is better than Chinese herbaceous peony at this timeLight, photodiode enables control circuit apply voltage to the ionosphere of mirror surface, in voltage control circuit output signalUnder effect, mirror surface can be dimmed, and the dazzling light of front vehicle becomes dim and soft.
Anti-dazzle driving mirror voltage range is 0V-1.2V, and voltage value is bigger, and specular color is deeper, but traditional anti-dazzleMesh rearview mirror can only export the voltage value of 0V or 1.2V, and voltage value is non-adjustable, and mirror surface only has transparent two kinds most deep with colorThe form of expression causes in the case where the headlamp direct projection rearview mirror of rear car, and driver is also difficult to obtain the traveling of front vehicleSituation further influences traffic safety.
Summary of the invention
The invention reside in a kind of anti-dazzle driving mirror driving circuit of adjustable transparency is provided, solve existing anti-dazzleMesh rearview mirror driving circuit can only enable rearview mirror have the most deep two kinds of manifestation modes of transparent and color, and voltage value is non-adjustable, leadsIt causes in the case where the front truck light irradiation rearview mirror of rear car, driver is difficult to the problem of obtaining the travel situations of front vehicle.
The invention proposes a kind of anti-dazzle driving mirror driving circuits of adjustable transparency, are equipped with voltage regulator circuit；InstituteStating voltage regulator circuit includes the first resistor and second resistance being arranged in series；It is additionally provided with resistance；Described resistance one end connection described theThe common connection end of one resistance and second resistance, the other end is as voltage input end.
Preferably, the voltage input is terminated with adjustable voltage V3。
Preferably, the output voltage of the voltage regulator circuitAnti-dazzle driving mirror driving electricityThe output voltage on road
Preferably, the voltage input is terminated with pwm signal input terminal.
Preferably, the voltage input end has pwm signal by the access of concatenated 4th resistance.
Preferably, including first capacitor C1；The first capacitor C1One end connects the resistance R3With the 4th resistance R4Be total toSame connecting pin, other end ground connection.
Preferably, the voltage regulator circuit further includes driving chip 10 and inductance L；The driving core is connected in the inductance LThe end SW of piece 10 and second resistance R2, and export the output voltage VEC；The end the FB connection described first of the driving chip 10Resistance R1With second resistance R2Common connection end, and with the resistance R3It is arranged in series.
Preferably, the BOOT of the driving chip 10 is terminated with pull-up circuit.
Preferably, the pull-up circuit includes the second capacitor C2With voltage-stabiliser tube D；The second capacitor C2Described in the connection of one endThe end BOOT, the other end are connected with the cathode of the voltage-stabiliser tube D, the plus earth of the voltage-stabiliser tube D；The cathode of the voltage-stabiliser tube DIt is connect with the end SW.
From the foregoing, it will be observed that available following using technical solution provided by the invention the utility model has the advantages that proposed by the present invention anti-Dazzle the eyes rearview mirror driving circuit to add divider resistance, enables output voltage values VECIncessantly by single value VFBIt determines, user can be withBy controlling input voltage V3Value control output voltage values, enable output voltage values have space and the possibility of regulation, can be realExisting a certain range of consecutive variations namely rearview mirror can realize different transparencies, reduce rear car headlamp to driverIn the case where influence, the function of the driving condition of rearview mirror reflection rear car can be retained.
Detailed description of the invention
In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, to embodiment or will show belowThere is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is only thisSome embodiments of invention without any creative labor, may be used also for those of ordinary skill in the artTo obtain other drawings based on these drawings.
Fig. 1 is the circuit diagram of the voltage regulator circuit of the embodiment of the present invention；
Fig. 2 is that voltage input end connects adjustable voltage V in anti-dazzle driving mirror driving circuit in the embodiment of the present invention3ElectricityLu Tu；
Fig. 3 is voltage input end in anti-dazzle driving mirror driving circuit in the embodiment of the present invention as pwm signal input terminalCircuit diagram.
10: voltage regulator circuit；11: driving chip；20: voltage input end；
21:PWM signal.
Specific embodiment
Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, completeSite preparation description.Obviously, described embodiment is only section Example of the present invention, instead of all the embodiments.Based on thisEmbodiment in invention, those of ordinary skill in the art's every other reality obtained under that premise of not paying creative laborExample is applied, shall fall within the protection scope of the present invention.
Existing anti-dazzle driving mirror driving circuit can only enable rearview mirror have the most deep two kinds of manifestation modes of transparent and color,Voltage value is non-adjustable, causes in the case where the front truck light irradiation rearview mirror of rear car, driver is difficult to obtain the row of front vehicleThe problem of sailing situation.
As shown in Figure 1 to Figure 3, to solve the above-mentioned problems, the present embodiment proposes a kind of preventing for adjustable transparencyDazzle the eyes rearview mirror driving circuit, mainly includes voltage regulator circuit 10；It include the first resistor being arranged in series in voltage regulator circuit 10R1With second resistance R2；The anti-dazzle driving mirror driving circuit of the present embodiment includes resistance R3；Resistance R3One end connects first resistorR1With second resistance R2Common connection end, the other end is as voltage input end 20.In the present embodiment, by adding resistance R3With voltage input end 20, enable the output voltage of anti-dazzle driving mirror driving circuit can be electric by adjusting the input of voltage input end 20Gas value carries out, and since voltage input end 20 can input the input electrical value of continuous function, driving circuit, which can get, to be connectedThe output voltage of continuous variation.
As shown in Fig. 2, in the present embodiment, voltage input end 20 is connected to adjustable voltage V3, voltage regulator circuit in the present embodiment10 output voltageThe output voltage of anti-dazzle driving mirror driving circuitTherefore adjustable voltage V is introduced in the present embodiment3, enable output voltageVECIncessantly by feedback voltage VFBIt determines, also by adjustable voltage V3It determines, and adjustable voltage V3It is more convenient for controlling, and can be according to anti-dazzleThe Output Voltage Formula of mesh rearview mirror driving circuit is it is found that work as adjustable voltage V3Numerical value it is bigger, output voltage VECValue it is smaller,User can be adjusted according to actual needs.
As shown in figure 3, voltage input end 20 is connected to pwm signal 21.Pwm signal 21 is constant in control circuit output frequencyIn the case where, its duty ratio is adjusted by Voltage Feedback, to achieve the purpose that stabilize the output voltage.Therefore user can lead toThe duty ratio for crossing adjustment pwm signal 21 obtains different output voltage values, and since PWM signal generator belongs to mature devicePart, user can directly make improvements existing rearview mirror driving circuit, enable rearview mirror in the strong illumination for receiving rear car, stillIt can keep the function of its mirror-reflection.
Anti-dazzle driving mirror driving circuit in the present embodiment further includes having the 4th resistance R4；4th resistance R4Access resistanceR3Between pwm signal 21.
The anti-dazzle driving mirror driving circuit of the present embodiment further includes first capacitor C1；First capacitor C1One end connect electricityHinder R3With the 4th resistance R4Common connection end, the other end ground connection.
Voltage regulator circuit 10 in the present embodiment further includes driving chip 11 and inductance L；Driving chip 11 is connected in inductance LThe end SW and second resistance R2, and export output voltage VEC；The end FB of driving chip 11 connects first resistor R1With second resistance R2'sCommon connection end, and with resistance R3It is arranged in series.
Wherein, the end BOOT of driving chip 11 is connected with pull-up circuit 30.Pull-up circuit 30 specifically includes the second capacitor C2And voltage-stabiliser tube D；Second capacitor C2One end connect the end BOOT, the other end connect voltage-stabiliser tube D cathode, the anode of voltage-stabiliser tube DGround connection；The cathode of the D of voltage-stabiliser tube is also connect with the end SW of driving chip 11.
In conclusion the present embodiment proposes a kind of anti-dazzle driving mirror driving circuit of adjustable transparency,Resistance and voltage input end 20 have been added on the basis of existing voltage regulator circuit, enable the size of output voltage no longer only by feedback electricityPressure determines, but the voltage value by inputting from voltage input end 20 and feedback voltage codetermine, therefore user can lead toOverregulating input voltage value enables rearview mirror different transparencies occur, can be adjusted according to actual needs, and rear car is enabled to have by forceWhen light is irradiated on rearview mirror, remove the case where emergency light reflex influences traffic safety into the eyes of driver appearance from.
Embodiments described above does not constitute the restriction to the technical solution protection scope.It is any in above-mentioned implementationMade modifications, equivalent substitutions and improvements etc., should be included in the protection model of the technical solution within the spirit and principle of modeWithin enclosing.