A kind of compatible LED circuit
Technical field
The present invention relates to LED illumination application, be specifically related to a kind of compatible LED circuit.
Background technology
LED has power and energy saving and the feature of life-span length, and more and more people use LED lamp tube directly to replace fluorescent lamp
Pipe, and the startup of LED generally has two ways;
The first is that the rectified filtering of voltage of ballast output is become unidirectional current, then uses the Switching Power Supply of non-isolated to do two
Secondary power is converted to drive LED voltage and current, and the advantage of this mode is can be suitable for electric ballast and inductance type simultaneously
Ballast, shortcoming is that cost is high, and Switching Power Supply can produce stronger EMI radiation interference, and can be to having in electrical power is changed
A little electric ballasts exert an adverse impact and even damage;
The second way is to use the linear circuit of low cost, the power of electric ballast output through simple blood pressure lowering constant current
Processing, this mode can only the fluorescent tube of compatible electronic ballast, it is impossible to for inductance type ballast, simultaneously to ballast output work
Rate makees to lower the limited use of regulation, so has influence on the effect of energy-saving application.
Summary of the invention
It is an object of the invention to for above-mentioned deficiency of the prior art, it is provided that can simultaneously compatible electronic ballast and
The LED circuit of Inductive ballast.
For achieving the above object, the concrete scheme of the present invention is as follows: a kind of compatible LED circuit, includes RC parallel connection electricity
Road, full bridge rectifier, LED group;One termination power of described RC parallel circuit;The other end of described RC parallel circuit is with complete
One input of bridge rectification circuit connects;Another input termination power of described full bridge rectifier;Described full-bridge rectification
One outfan of circuit is connected with one end of LED group;Another of the other end of described LED group and full bridge rectifier
Outfan connects;Also include electric capacity C2, electric capacity C2 in parallel with LED group.
The present invention is further arranged to, described full bridge rectifier include diode D1, diode D2, diode D3 and
Diode D4;The negative pole of described diode D1 and the positive pole of diode D2 connect;The negative pole of described diode D2 and diode D3
Negative pole connect;The positive pole of described diode D3 and the negative pole of diode D4 connect;The positive pole of described diode D4 and diode
The positive pole of D2 connects;
The other end of described RC parallel circuit is connected with the negative pole of diode D1;One end of described LED group is with diode D2's
Negative pole connects;The other end of described LED group and the positive pole of diode D4 connect;The positive pole of described diode D3 connects power supply.
The present invention is further arranged to, and also includes protective tube F;Described protective tube F be located at RC parallel circuit and power supply it
Between.
The present invention is further arranged to, and also includes inductance L;It is defeated that described inductance L is located at another of full bridge rectifier
Enter between end and power supply.
Beneficial effects of the present invention:
1. the present invention passes through RC parallel circuit, it is possible to alternating current electric ballast and Inductive ballast exported, and carries out blood pressure lowering
And current limliting, then by full bridge rectifier, the alternating current through RC parallel circuit being carried out rectification, output is suitable for what LED ran
Electric current;
The most in addition, the present invention can be directly connected to electric main, and circuit is similar to a RC capacitance-resistance voltage reduction circuit, change-over circuit
Work in the state close to constant current, thus the fluorescent tube that can also act on single direct-connected civil power uses;
3. the present invention passes through simple circuit and element so that electric ballast, Inductive ballast and civil power can use same
One passage, it is achieved compatible function, simple in construction, cost-effective.
Accompanying drawing explanation
Utilize accompanying drawing that invention is described further, but the embodiment in accompanying drawing do not constitute any limitation of the invention,
For those of ordinary skill in the art, on the premise of not paying creative work, it is also possible to obtain it according to the following drawings
Its accompanying drawing.
Fig. 1 is the schematic diagram of the embodiment of the present invention 1;
Fig. 2 is the schematic diagram of the embodiment of the present invention 2;
Fig. 3 is the schematic diagram that the embodiment of the present invention 2 coordinates with electric ballast.
Detailed description of the invention
The invention will be further described with the following Examples.
Embodiment 1
As it is shown in figure 1, a kind of compatible LED circuit described in the present embodiment, include RC parallel circuit, full bridge rectifier,
LED group;One termination power of described RC parallel circuit;The other end of described RC parallel circuit with one of full bridge rectifier
Input connects;Another input termination power of described full bridge rectifier;One outfan of described full bridge rectifier
It is connected with one end of LED group;The other end of described LED group is connected with another outfan of full bridge rectifier;Also wrap
Electric capacity C2, electric capacity C2 are included in parallel with LED group.The present invention passes through RC parallel circuit, it is possible to by electric ballast and inductance town
The alternating current of stream device output, carries out blood pressure lowering and current limliting, then by full bridge rectifier to the alternating current through RC parallel circuit
Carrying out rectification, output is suitable for the electric current that LED runs;In addition, the present invention can be directly connected to electric main, and circuit is similar to one
Individual RC capacitance-resistance voltage reduction circuit, change-over circuit works in the state close to constant current, thus can also act on single direct-connected civil power
Fluorescent tube uses;The present invention passes through simple circuit and element so that electric ballast, Inductive ballast and civil power can use
Same passage, it is achieved compatible function, simple in construction, cost-effective.
A kind of compatible LED circuit described in the present embodiment, described full bridge rectifier includes diode D1, diode
D2, diode D3 and diode D4;The negative pole of described diode D1 and the positive pole of diode D2 connect;Described diode D2's is negative
The negative pole of pole and diode D3 connects;The positive pole of described diode D3 and the negative pole of diode D4 connect;Described diode D4's
The positive pole of positive pole and diode D2 connects;
The other end of described RC parallel circuit is connected with the negative pole of diode D1;One end of described LED group is with diode D2's
Negative pole connects;The other end of described LED group and the positive pole of diode D4 connect;The positive pole of described diode D3 connects power supply.
A kind of compatible LED circuit described in the present embodiment, also includes protective tube F;It is in parallel that described protective tube F is located at RC
Between circuit and power supply.
Embodiment 2
As shown in Figures 2 and 3, as different from Example 1, the present invention is further arranged to, and also includes inductance L;Described electricity
Sense L is located between another input and power supply of full bridge rectifier.
The circuit described in embodiment 1 is debugged when, it is found by the applicant that the circuit described in embodiment 1 is in compatibility
During electric ballast, LED group can produce problems with: 1. producing bigger hot spot affects the even photosensitiveness of whole lamp;The most whole lamp
Temperature is too high makes the LED group life-span reduce;3. power consumption is big;The light decay of 4.LED is serious;The stroboscopic situation of 5.LED is serious.
In order to solve problem above, applicant attempt changing LED structure the formation and the structure of light guide plate is to improve hot spot problem,
And dispel the heat by the structure changing LED and reduce the light decay of LED, but finding that such change is all cured the symptoms, not the disease,
Solving hot spot and temperature problem when, substantially increase cost, and the problem that power consumption is big can not be solved.
Applicant, through test the most repeatedly and checking, is just found that LED group produces problem above, is due to electricity
After the alternating current of 50HZ/60HZ is converted to the high-frequency alternating current of 20-50KHZ by sub-ballast, flow through the electric current mistake of LED circuit
Greatly so that temperature is too high, LED light is caused to decline serious and increase power consumption;Simultaneously because electric current is excessive so that the stroboscopic of LED
Problem is serious.Therefore applicant adds inductance L between electric ballast and LED, it is notable that before the application also
Nobody attempts solving, by this mode, above-mentioned five kinds of problems that LED group produces.
Specifically, when the application of this circuit is to electric ballast, as shown in Figures 2 and 3, electric ballast is by 50HZ/
After the alternating current of 60HZ is converted to the high-frequency alternating current of 20-50KHZ, through the bleeder resistance R group of inductance L, electric capacity C and electric capacity C
The loop become, due to the capacitive reactance of electric capacity CIt is inversely proportional to capacitance, and the capacity of electric capacity C is big, therefore electric capacity C
Capacitive reactance little so that electric capacity C has the characteristic of logical high frequency resistance low frequency, therefore the impact on high frequency is the least;
And inductance L serve in the circuit filtering, vibrate, postpone, the effect such as trap;Filtering, due to from electric ballast stream
The electric current crossed has bigger frequency, and LED is created harmful effect, by the effect of inductance L electric current can be filtered into
The electric current of LED adaptation frequency;Vibration, inductance, hindering curent change when, does not consume electric energy, and it can be by the energy of electricity
Temporarily store with the form in magnetic field, again the energy in magnetic field is discharged the when of waiting electric current to reduce;Postpone, due to inductance
There is the effect hindering curent change, it is possible to make LED postpone to open or late release, LED is played a protective role;Exist simultaneously
In alternating current, inductance L produces induction reactance, the impedance of inductance L is directly proportional to frequency so that inductance L has logical low frequency resistance height
The characteristic of frequency;
Therefore the total impedance of circuit isAs long as, therefore select suitable inductance, i.e. can increase electricity
The total impedance on road, it is possible to limit the electric current by LED lamp tube, reduce whole lamp output so that light decay reduces, temperature drops
Low, and decrease consumption, save the energy, simultaneously because current reduction so that LED can bear current intensity now, no
One bright one phenomenon gone out occurs again, decreases stroboscopic phenomenon.
When this circuit is applied to Inductive ballast, electric capacity C goes out impedance to the low frequency behavior of civil power, properly selects voltage
Relatively low LED group, it is possible to reach the effect of constant current, and inductance L is less to the induction reactance of low-frequency electrical, therefore to electric current and the shadow of power
Ring little.
When this circuit is directly accessed 220V or 110V electric main, circuit is similar to a RC capacitance-resistance voltage reduction circuit, electricity
Road works in close to constant current state so that LED group normal operation.
Last it should be noted that, above example is only in order to illustrate technical scheme, rather than the present invention is protected
Protecting the restriction of scope, although having made to explain to the present invention with reference to preferred embodiment, those of ordinary skill in the art should
Work as understanding, the technical scheme of invention can be modified or equivalent, without deviating from the essence of technical solution of the present invention
And scope.