CN207219122U

CN207219122U - A kind of digital timing invariable power directly driven by AC LED circuit

Info

Publication number: CN207219122U
Application number: CN201721238156.9U
Authority: CN
Inventors: 颜晓钟
Original assignee: Danyang Deyu New Energy Application Co Ltd
Current assignee: Danyang Deyu New Energy Application Co Ltd
Priority date: 2017-09-26
Filing date: 2017-09-26
Publication date: 2018-04-10
Anticipated expiration: 2027-09-26

Abstract

The utility model discloses a kind of digital timing invariable power directly driven by AC LED circuit, including a rectifier bridge, one MCU, n can turn off constant-current circuit, n accessory power supply and n LED string, the 50Hz sine wave ACs electric rectification of input is 100Hz all-waves by the rectifier bridge, it is added in accessory power supply, the circuit both ends that LED string and constant-current circuit are in series, the accessory power supply provides operating voltage for MCU, MCU samples to input voltage, on the basis of input current flows through the zero-time, constant-current circuit shut-off and the time opened can be turned off by calculating n, and export n way switch amount signals and constant-current circuit is controlled.The control of the utility model passage time solves the problems, such as the change in duty cycle that input voltage change is brought, and makes the current effective value for flowing through LED in each cycle constant, effectively increases line regulation, make lamp string stable luminescence, do not change with the change of input voltage.

Description

A kind of digital timing invariable power directly driven by AC LED circuit

Technical field

It the utility model is related to LED circuit technical field, more particularly to a kind of digital timing invariable power directly driven by AC LED circuit.

Background technology

South Korea Seoul semiconductor can directly drive the ACLED that make lamp luminescence in utility model in 2005 with direct current, Also utility model single chip LED (ACLED), system application scheme greatly simplifies U.S. III-N Technology, System effectiveness reaches more than 92%.

Taiwan " Industrial Technology Research Institute " 2008 complete industrialization production and there can be the ACLED of real application systems scheme Product, directly plug-in it can make its AC light-emitting in the AC110V alternating voltages of 60Hz or higher frequency.

But in ACLED lamp circuits, LED both ends are applied directly to after alternating voltage is rectified.Due to LED conducting threshold values electricity The presence of pressure, LED are only just turned on after input voltage is higher than threshold voltage, and power factor only has 0.65 or so, conducting electric current ripple Shape is pulsating direct current, and when input voltage and LED threshold values are constant, dutycycle is constant.

In addition, the frequency of exchange input is relatively stable, but as input voltage can determine because of grid supply quality, one Fluctuated in fixed scope, when input ac voltage reduces, voltage reaches the time length required for LED threshold values, LED current duty Than reducing, the current effective value for flowing through LED reduces, and light fixture is dimmed；When input ac voltage raises, voltage reaches LED threshold values The required time is short, and LED current dutycycle becomes big, and the current effective value for flowing through LED becomes big, and light fixture brightens.That is, exchange ACLED circuits, its work influenceed by voltage pulsation, and brightness can change with the change of input voltage, it is impossible to is provided stable Light output.

Utility model content

The purpose of this utility model has that power factor is low, brightness changes and changed with input voltage for prior art Problem is solved, there is provided the good High Power Factor of a kind of long-life, low cost, power savings, operating current be not with input electricity Buckling and the LED illumination lamp drive control circuit changed.

To achieve the above objectives, the utility model, which adopts the following technical scheme that, is achieved：

A kind of digital timing invariable power directly driven by AC LED circuit, including a rectifier bridge, a microprocessor （MCU）, n can turn off constant-current circuit, n accessory power supply and LED string.Rectifier bridge is whole by the 50Hz sine wave alternating currents of input Flow for 100Hz all-waves, be added in accessory power supply, the circuit both ends that LED string and constant-current circuit are in series.Accessory power supply is MCU Operating voltage is provided, MCU is sampled to input voltage, and on the basis of input current flows through the zero-time, perseverance can be turned off by calculating n The time that current circuit is turned off and opened, and export n way switch amount signals and constant-current circuit is controlled.Constant-current circuit can be turned off LED points are n sections by (i=1,2,3 ... n, n >=2), and every section of LED quantity both may be the same or different, and can each turn off constant current The operating current of circuit can be configured according to design requirement, obtain different operating current waveforms, the work needed for constant-current circuit Making voltage can both be provided by auxiliary circuit, can also be obtained from 100Hz all-waves.N can turn off in constant-current circuit, can each turn off The input of constant-current circuit terminates corresponding LED negative terminal, the negative terminal of output termination rectifier bridge.

Further, because the 50Hz frequencies of input AC electricity are highly stable, the 100Hz all-wave cycles after corresponding rectification Also it is highly stable 10ms.

Further, each whole wave periods are divided into n sections by MCU according to the raising and lowering of waveform, are risen in waveform Period phase is arranged by ascending power（i=1,2……n）, decline period phase by drop power arrangement in waveform（i=n……2,1）, when Between in section, corresponding the constant-current circuit conducting, remaining constant-current circuit is turned off；With the raising and lowering of voltage, MCU according to Constant-current circuit can be turned off by controlling n successively according to regular time, to make the electric current for flowing through every section of LED, can so cause voltage During change, every section of voltage can be fully utilized, and according to input voltage peak change but cycle constant characteristic, pass through MCU controls operating current dutycycle is constant, keeps operating current virtual value constant, reaches and improve power factor and line regulation Purpose.

Compared with prior art, the beneficial effects of the utility model are：

1st, the utility model to the time of each cycle by detecting, and then controls the working condition of each constant-current circuit With LED quantity, so as to correct the waveform of input current, improve power factor, and passage time control solve it is defeated Enter the change in duty cycle problem that voltage change is brought, make the current effective value for flowing through LED in each cycle constant, effectively increase electricity Source regulation, make lamp string stable luminescence, do not change with the change of input voltage.

2nd, circuit used in the utility model is without the electrochemical capacitor for influenceing lamp life, semiconductor devices and electricity in circuit The life-span of resistance and LED life match, and can reach more than 50,000 hours, also higher than conventional LED drive power, and having Very high power factor（Up to 0.99）, the pollution to power network is effectively reduced, and when alternating voltage changes, the time cycle LED power supply is flowed through in accurate control, makes LED steady operations, substantially increases the reliability of light fixture.

Brief description of the drawings

Fig. 1 is structural representation of the present utility model.

Fig. 2 is circuit theory diagrams when constant-current circuit of the present utility model turns off.

Fig. 3 is circuit theory diagrams when constant-current circuit of the present utility model is opened.

Fig. 4 is the oscillogram of input voltage of the present utility model and input current.

Label in figure：

1- rectifier bridges 2-n can turn off 3-n LED string of constant-current circuit.

Embodiment

Below to being elaborated with reference to accompanying drawing to preferred embodiment of the present utility model, so that the advantages of the utility model It can be easier to be readily appreciated by one skilled in the art with feature, it is apparent clear and definite so as to be made to the scope of protection of the utility model Define.

Referring to shown in Fig. 1, Fig. 2, Fig. 3 and Fig. 4, a kind of digital timing invariable power directly driven by AC LED circuit, including one Individual 1, MCU of rectifier bridge（Not shown in figure）, n can turn off constant-current circuit 2, n accessory power supply（Not shown in figure）With n The 50Hz sine wave ACs electric rectification of input is 100Hz all-waves by LED string 3, the rectifier bridge 1, is added in accessory power supply, LED The circuit both ends that lamp string and constant-current circuit are in series, the accessory power supply provide operating voltage for MCU, and MCU is to input voltage Sampled, on the basis of input current flows through the zero-time, the time that constant-current circuit 2 is turned off and opened can be turned off by calculating n, and Output n way switch amount signals are controlled to constant-current circuit, and described to turn off constant-current circuit by LED point be n sections, every section of LED's Quantity both may be the same or different, and can each turn off the operating current of constant-current circuit and can be configured according to design requirement, obtain Different operating current waveforms, the operating voltage needed for constant-current circuit can both be provided by auxiliary circuit, also can be from 100Hz all-waves Obtain, the n can turn off in constant-current circuit 2, and the input that can each turn off constant-current circuit terminates corresponding LED negative terminal, defeated Go out to terminate the negative terminal of rectifier bridge.

The 50Hz frequencies of input AC electricity are highly stable, and the 100Hz all-wave cycles after corresponding rectification are also to be highly stable 10ms.

Operation principle of the present utility model：Each whole wave periods are divided into n sections by MCU according to the raising and lowering of waveform, Arranged in period waveform rising stage by ascending power（i=1,2……n）, decline period phase by drop power arrangement in waveform（i=n…… 2,1）, within the period, corresponding the constant-current circuit conducting, remaining constant-current circuit is turned off.With voltage rising and Decline, MCU controls n successively according to regular time can turn off constant-current circuit, to make the electric current for flowing through every section of LED, so both Can cause voltage change when, every section of voltage can be fully utilized, but according to input voltage peak change but the cycle it is constant Characteristic, by MCU control operating current dutycycle it is constant, keep operating current virtual value it is constant, reach raising power factor With the purpose of line regulation.

To sum up shown, the utility model controls each constant-current circuit by being detected to the time of each cycle The quantity of working condition and LED, so as to correct the waveform of input current, power factor is improved, and passage time controls Solve the problems, such as the change in duty cycle that input voltage change is brought, make the current effective value for flowing through LED in each cycle constant, effectively Line regulation is improved, makes lamp string stable luminescence, does not change with the change of input voltage.

Better embodiment of the present utility model is the foregoing is only, the scope of protection of the utility model is not with above-mentioned reality The mode of applying is limited, as long as equivalent modification that those of ordinary skill in the art are made according to the utility model disclosure or change Change, should all include in the protection domain described in claims.

Claims

1. a kind of digital timing invariable power directly driven by AC LED circuit, including a rectifier bridge, one MCU, n can turn off Constant-current circuit, n accessory power supply and n LED string, it is characterised in that：The rectifier bridge is by the 50Hz sine wave ACs of input Electric rectification is 100Hz all-waves, is added in accessory power supply, the circuit both ends that LED string and constant-current circuit are in series, the auxiliary electricity Source provides operating voltage for MCU, and MCU samples to input voltage, on the basis of input current flows through the zero-time, calculates n Constant-current circuit shut-off and the time opened can be turned off, and exports n way switch amount signals and constant-current circuit is controlled.