CN104427716B - Light emitting diode driving circuit - Google Patents
Light emitting diode driving circuit Download PDFInfo
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- CN104427716B CN104427716B CN201410400736.8A CN201410400736A CN104427716B CN 104427716 B CN104427716 B CN 104427716B CN 201410400736 A CN201410400736 A CN 201410400736A CN 104427716 B CN104427716 B CN 104427716B
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Abstract
A light emitting diode driving circuit includes: a conversion circuit, a control circuit, and a dimming signal shift circuit. The conversion circuit is used for converting an input voltage and providing a stable output current to drive the light emitting diode load. The dimming signal displacement circuit receives a dimming signal corresponding to the voltage of the ground terminal, and adjusts the dimming signal into a dimming input signal corresponding to the floating ground voltage through a dimming diode and a dimming capacitor electrically connected with the floating ground voltage, and the dimming input signal after signal recovery can be obtained after the signal recovery is carried out through a dimming signal recovery module of the control circuit, so that the dimming signal displacement circuit has the effects of saving the circuit volume and the cost and overcoming the problem caused by the non-uniform reference ground voltage.
Description
Technical field
The present invention relates to a kind of drive circuit, particularly relate to a kind of light emitting diode and drive electricity
Road.
Background technology
In recent years, due to light emitting diode (Light-Emitting-Diode is abbreviated as LED)
There is many be suitable for the characteristic of illumination and easily dim so that light emitting diode is gradually subject to
The attention in market, and be widely used in various ligthing paraphernalia.
Light emitting diode is a kind of element using low-voltage direct-current to drive, typically at general illumination
In the application of (General Lighting), usually can arrange in pairs or groups use buck-converter (Buck
Converter), falling-rising voltage type transducer (Buck-Boost Converter) or flyback turn
Parallel operation (Flyback Converter) is as its drive circuit.
Refering to Fig. 1 and Fig. 2, general buck-converter (such as Fig. 1) and falling-rising voltage type transducer
In (such as Fig. 2), switch element 11 is generally arranged at high-end (High Side), and in order to drive
Move and be positioned at high-end switch element 11, it will usually use high-end switch actuation techniques as shown in Figure 1
(High Side Driver Technique), arranges a high-end switch drive circuit 12, and
It is controlled with a control circuit 13；Or use floating earth as shown in Figure 2
(Floating Ground) mode, is electrically connected the reference floating earth end 131 of control circuit 13
It is connected between diode D and winding L, to obtain a floating earth voltage.
But, either use high-end switch actuation techniques or floating earth mode, all can make
The reference earthing potential (floating earth voltage) of high-end switch drive circuit 12 or control circuit 13
It is different potentials with the reference earthing potential (earth terminal) of system, so causes signal transmitting
Journey does not have unified reference earthing potential signal can be caused normally to be transmitted for reference
Or detecting.
Refering to Fig. 3 and Fig. 4, currently in order to solve this problem, it will usually use as shown in Figure 3
One isolating transformer 14, or use a photo-coupler 15 to transmit news as shown in Figure 4
Number, to overcome with reference to the inconsistent impact on signal transmission of earthing potential.
But isolating transformer 14 and photo-coupler 15 all can make circuit volume rise, increase electricity
Road cost and design complexities, even can affect the reliability of system.
Summary of the invention
It is an object of the invention to provide a kind of light emitting diode that can solve the problems referred to above to drive
Circuit.
LED driving circuit of the present invention, it is adaptable to drive multiple light emitting diode, this
Optical diode drive circuit comprises a change-over circuit and a control circuit.
This change-over circuit includes a switch element, an output capacitance, an inductance and one
Flywheel diode.
This switch element has one and receives the first end of a power signal, second end,
And one receive one control signal control end, controlled and in conducting and cut-off between switch.
This output capacitance has one provides an output electric current to drive described light emitting diode
The first end, and one electrical connection one earth terminal the second end.
This inductance and this flywheel diode are serially connected with between the first end of this output capacitance and earth terminal,
And its junction point is electrically connected to the second end of this switch element and provides a floating earth voltage.
This control circuit include switch element control end, one with reference to floating earth end, one
Individual light modulation signal input end, a light modulation signal reply module, a brightness adjustment control module.
This switch element controls end and electrically connects the control end of this switch element and provide this control to interrogate
Number.
This reference floating earth end is electrically connected to the junction point of this inductance and this flywheel diode, with
Receive this floating earth voltage.
This light modulation signal input end for receive one to should the light modulation of floating earth voltage defeated
Enter signal.
This light modulation signal reply module electrically connects this light modulation signal input end and this reference is floated and connect
Ground end, defeated after receiving this light modulation input signal and this light modulation input signal being carried out signal reply
Go out.
This brightness adjustment control module electrically connects this light modulation signal and replys module and the control of this switch element
End, receives this light modulation input signal after signal is replied, and according to this light modulation input after replying
Signal adjusts and exports this control signal.
This LED driving circuit also comprises a light modulation signal shift circuit, and this light modulation is interrogated
Number shift circuit includes a light modulation diode and a dimming capacitors.
This light modulation diode has an anode tap receiving a light modulation signal, and an output
The cathode terminal of this light modulation input signal.
This dimming capacitors has the first end of a cathode terminal electrically connecting this light modulation diode, and
One the second end receiving this floating earth voltage.
LED driving circuit of the present invention, this light modulation signal is replied module and is had one
Comparator, this comparator receives this light modulation input signal and compares with a predetermined voltage, with
This light modulation input signal after output signal reply.
LED driving circuit of the present invention, this light modulation signal replys what module was exported
This light modulation input signal after signal reply, its pulse bandwidth and frequency are essentially the same as this tune
Light signal.
LED driving circuit of the present invention, this comparator has a normal phase input end
And an inverting input.
This light modulation signal is replied module and is also had sampling diode, a sampling capacitor, and
One scheduled voltage.
This sampling diode has an anode tap receiving this light modulation input signal, and an electricity
Connect the cathode terminal of this comparator normal phase input end.
This sampling capacitor has the first end of a cathode terminal electrically connecting this sampling diode, and
One the second end receiving this floating earth voltage.
This scheduled voltage has one and electrically connects this comparator inverting input and provide this pre-
Determine the first end of voltage, and the second end of second end electrically connecting this sampling capacitor.
LED driving circuit of the present invention, also comprises one for receiving an exchange
Power supply is to export the power circuit of this power signal, and this alternating current power supply has first end and
Individual second end, this power circuit includes a bridge rectifier module, and this bridge rectifier module has
One the first diode, the second diode, the 3rd diode, and one the four or two
Pole is managed.
This first diode has the anode tap of first end electrically connecting this alternating current power supply, and
The cathode terminal of one the first end electrically connecting this switch element.
This second diode has an anode tap electrically connecting this earth terminal, and an electrical connection
The cathode terminal of the first end of this alternating current power supply.
3rd diode has the anode tap of second end electrically connecting this alternating current power supply, and
The cathode terminal of one the first end electrically connecting this switch element.
4th diode has an anode tap electrically connecting this earth terminal, and an electrical connection
The cathode terminal of the second end of this alternating current power supply.
LED driving circuit of the present invention, this power circuit also includes a filtered electrical
Hold.
This filter capacitor has the first end of first end electrically connecting this switch element, and one
Second end of individual this earth terminal of electrical connection.
LED driving circuit of the present invention, this power circuit also includes an electrical connection
EMI Filtering module between this alternating current power supply and this bridge rectifier module.
LED driving circuit of the present invention, this EMI Filtering module has one
EMI Filtering inductance, and an EMI Filtering electric capacity.
This EMI Filtering inductance has the of first end electrically connecting this alternating current power supply
One end, and the second end of an anode tap electrically connecting this first diode.
This EMI Filtering electric capacity has one and electrically connects the of this EMI Filtering inductance
First end of two ends, and the second end of second end electrically connecting this alternating current power supply.
LED driving circuit of the present invention, in this change-over circuit:
This flywheel diode has an anode tap electrically connecting this earth terminal, and an electrical connection
The cathode terminal of the second end of this switch element.
This inductance has the first end of a cathode terminal electrically connecting this flywheel diode, and one
Electrically connect the second end of the first end of this output capacitance.
LED driving circuit of the present invention, in this change-over circuit:
This flywheel diode has the anode tap of first end electrically connecting this output capacitance, and
The cathode terminal of one the second end electrically connecting this switch element.
This inductance has the first end of a cathode terminal electrically connecting this flywheel diode, and one
Electrically connect the second end of this earth terminal.
The beneficial effect of the present invention is: by using this dimming capacitors and this light modulation diode
Replace isolating transformer of the prior art or photo-coupler, not only can save circuit body in a large number
Amass and element, reduction circuit cost, and in signal transmittance process, there is no unified reference potential
Can for reference in the case of, still can normal detection or transmitting signals.
Accompanying drawing explanation
Fig. 1 is a circuit diagram, and existing a kind of buck-converter and high-end of using is described
The LED driving circuit of switch actuation techniques；
Fig. 2 is a circuit diagram, existing a kind of employing falling-rising voltage type transducer is described and floats
The LED driving circuit of dynamic earthing mode；
Fig. 3 is a circuit diagram, and existing a kind of employing isolating transformer transmitting signals is described
LED driving circuit；
Fig. 4 is a circuit diagram, and existing a kind of photo-coupler transmitting signals that uses is described
LED driving circuit；
Fig. 5 is the circuit signal of a first embodiment of LED driving circuit of the present invention
Figure；
Fig. 6 is the circuit diagram of a light modulation signal reply module of this first embodiment；
Fig. 7 is this first embodiment action equivalent circuit when a switching elements conductive
Figure；
Fig. 8 is this first embodiment action equivalent circuit when this switch element ends
Figure；
Fig. 9 is a circuit diagram in greater detail of this first embodiment；
Figure 10 is an analog waveform figure of this first embodiment；
Figure 11 is another analog waveform figure of this first embodiment；
Figure 12 is another pattern of this light modulation signal reply module of this first embodiment；
Figure 13 is the 3rd analog waveform figure of this first embodiment；
Figure 14 is the 4th analog waveform figure of this first embodiment；And
Figure 15 is that the circuit of second embodiment of LED driving circuit of the present invention shows
It is intended to.
Detailed description of the invention
Below in conjunction with the accompanying drawings and embodiment the present invention is described in detail.
Refering to Fig. 5 and Fig. 6, the first embodiment of LED driving circuit of the present invention is suitable for
In driving multiple light emitting diodes 9, this LED driving circuit comprises: a power supply electricity
2, one, road, 3, control circuit 4 of change-over circuit, and a light modulation signal shift circuit 5.
This power circuit 2 receives alternating current power supply Vac to export a power signal, this friendship
Stream power supply Vac has first end 201 and second end 202, and this power circuit 2 wraps
Include a bridge rectifier module 21.
This bridge rectifier module 21 has: the first diode D1, second diode
D2, a 3rd diode D3, and a 4th diode D4.
This first diode D1 has first end 201 electrically connecting this alternating current power supply Vac
Anode tap, and one electrically connect this change-over circuit 3 and export the cathode terminal of this power signal.
This second diode D2 has the anode tap of one earth terminal of an electrical connection, and one
Electrically connect the cathode terminal of the first end of this alternating current power supply Vac.
3rd diode D3 has second end 202 electrically connecting this alternating current power supply Vac
Anode tap, and one electrically connect this change-over circuit 3 and export the cathode terminal of this power signal.
4th diode D4 has an anode tap electrically connecting this earth terminal, and an electricity
Connect the cathode terminal of the second end of this alternating current power supply Vac.
This change-over circuit 3 is electrically connected to this power circuit 2, and includes: switch element Q1,
One output capacitance Co, an inductance L, and a flywheel diode Do.
In the present embodiment, decompression converting circuit (Buck Converter) is used to be used as explanation,
But it is not limited to this.
This switch element Q1 has cathode terminal and the reception of electrical connection a 3rd diode D3
First end of this power signal, second end, and the control receiving a control signal
End, controlled and in conducting and cut-off between switch.
This output capacitance Co has one provides an output voltage and output electric current to drive institute
State the first end of light emitting diode 9, and second end electrically connecting this earth terminal.
This flywheel diode Do has an anode tap electrically connecting this earth terminal, and an electricity
Connect second end of this switch element Q1 and the cathode terminal of a floating earth voltage is provided.
This inductance L has the first end of the cathode terminal of electrical connection this flywheel diode Do,
And the second end of first end electrically connecting this output capacitance Co.
This control circuit 4 includes: switch element control end GATE, a reference are floated and connect
Ground end VSS, light modulation signal input end DIM, a light modulation signal reply module 41, and
One brightness adjustment control module 42.
This switch element controls end GATE and electrically connects the control end of this switch element Q1 and provide this
Control signal.
This reference floating earth end VSS is electrically connected to this inductance L and this flywheel diode Do's
Junction point, to receive this floating earth voltage.
This light modulation signal input end DIM is for receiving one to should the light modulation of floating earth voltage
Input signal.
This light modulation signal is replied module 41 and is electrically connected this light modulation signal input end DIM and this reference
Floating earth end VSS, receives this light modulation input signal and this light modulation input signal is carried out signal
Export after reply.
This light modulation signal is replied module 41 and is had a comparator 411, and this comparator 411 receives
This light modulation input signal also compares with a predetermined voltage, this tune after replying with output signal
Light input signal, in the present embodiment, uses a scheduled voltage Vf to provide this predetermined electricity
Pressure, but be not limited.
This light modulation signal replys this light modulation input signal after the signal reply that module 41 is exported,
Its pulse bandwidth and frequency are essentially the same as this light modulation signal.
This brightness adjustment control module 42 electrically connects this light modulation signal and replys module 41 and this switch element
Control end GATE, receive this light modulation input signal after signal is replied, and according to being somebody's turn to do after replying
Light modulation input signal adjusts and exports this control signal.
This light modulation signal shift circuit 5 includes: a light modulation diode Ddim and a light modulation
Electric capacity Cdim.
This light modulation diode Ddim has one and receives one to should the light modulation of earth terminal voltage
The anode tap of signal, and output is to should this light modulation input signal of floating earth voltage
Cathode terminal.
This dimming capacitors Cdim has the cathode terminal of electrical connection this light modulation diode Ddim
First end, and second end receiving this floating earth voltage.
Refering to equivalent circuit diagram when Fig. 7 and Fig. 8, respectively switch element Q1 conducting and cut-off,
For making illustrative clarity understand, in Fig. 7 and Fig. 8, this alternating current power supply Vac and this power circuit
2 with equivalent source Vref after an all wave rectification as representative.
As it is shown in fig. 7, when this switch element Q1 turns on, this flywheel diode Do ends,
Now second end of this switch element Q1 is relatively high current potential, so this light modulation signal displacement electricity
Road 5 is ended due to light modulation diode Ddim reverse bias, and the equivalence after this all wave rectification
Power supply Vref stores energy to this inductance L.
As shown in Figure 8, when this switch element Q1 ends, this inductance L is by this flywheel two
Pole pipe Do releases energy and makes this flywheel diode Do conducts, now the second of this switch element Q1
Hold and be relatively low current potential for equivalence ground connection, so the light modulation in this light modulation signal shift circuit 5
Diode Ddim forward bias voltage drop and turn on to should the light modulation signal of earth terminal voltage obtain
To be sent on dimming capacitors Cdim, the cross-pressure of this dimming capacitors Cdim is made to approximate this light modulation
The voltage peak of signal.
Owing to the blood pressure lowering of this change-over circuit 3 is converted to, known to this industry, not repeat at this.
Refering to Fig. 5 and Fig. 6, this light modulation signal shift circuit 5 is in receiving corresponding earth terminal voltage
This light modulation signal after, by this light modulation diode Ddim and receive this floating earth voltage
Dimming capacitors Cdim, can be adjusted to should the light modulation of floating earth voltage by this light modulation signal
Input signal, then comparator 411 and this predetermined electricity of module 41 is replied via this light modulation signal
After pressure compares, this light modulation input signal after signal is replied can be obtained.
Refering to Fig. 6 and Fig. 9, wherein Fig. 9 is the circuit diagram in greater detail of the present embodiment,
Wherein:
This control circuit 4 also includes: one for receive the power end VDD of power supply, one return
Awarding end FB, and a phase compensation end COMP, this power end VDD is used for providing control circuit 4
Required power supply, this feedback end FB is for receiving corresponding to inductance L electric current and this output electric current
A feedback signal, this phase compensation end COMP for compensating the phase place of this feedback signal,
Make system stability.This control circuit 4 controls switch element Q1 by received feedback signal
Conducting and cut-off, and make change-over circuit 3 export this stable output electric current to drive this luminescence two
Pole pipe die group 9.
This power circuit 2 also includes an EMI Filtering module 22 and a filter capacitor
C1。
This EMI Filtering module 22 has: an EMI Filtering inductance Lf and one
EMI Filtering electric capacity Cf.
This EMI Filtering inductance Lf has one and electrically connects the first of this alternating current power supply Vac
First end of end 201, and the second end of the anode tap of electrical connection this first diode D1.
This EMI Filtering electric capacity Cf has electrical connection this EMI Filtering inductance Lf
The first end of the second end, and the of second end 202 electrically connecting this alternating current power supply Vac
Two ends.
It is noted that in the present embodiment, this EMI Filtering module 22 is only with one
An individual EMI Filtering inductance Lf and EMI Filtering electric capacity Cf is as signal, mainly
It is as Electromagnetic interference filter (EMIFilter), but Electromagnetic interference filter has multiple
Implementing aspect, person also can change according to this to have relevant knowledge in this area, is not limited.
This filter capacitor C1 has the first of first end of electrical connection this switch element Q1
End, and second end electrically connecting this earth terminal.
This change-over circuit 3 also includes that a feedback resistance Rfb, this feedback resistance Rfb are serially connected with
Between this inductance L and this flywheel diode Do, it is used for producing corresponding inductance L electric current and output electricity
This feedback signal of stream, and it is input to this feedback end FB, to reach inductance L electric current and output electricity
The back coupling of stream controls.
Refering to Fig. 6, Fig. 9 and Figure 10, Figure 10 show and uses the circuit of Fig. 6, Fig. 9 to be entered
The analog waveform figure of row, wherein, curve 91 is the light modulation signal inputted, and its on-state rate
(duty ratio) is 90%, and frequency is 600Hz, right via this light modulation signal shift circuit 5
Should floating earth voltage process after, the light modulation input signal exported i.e. curve 92, by scheming
In 10 visible, due to the impact of this floating earth voltage, the minimum electricity of curve 92 and curve 91
Position also differs, and the high potential value of curve 92 also has the phenomenon of floating, then via this tune
After light signal replys module 41 process, this light modulation input signal after the signal of gained is replied is
Curve 93, as seen from Figure 10, this light modulation input signal (curve 93) after signal reply
Pulse bandwidth and frequency are all same as this light modulation signal (curve 91).
Refering to Fig. 6, Fig. 9 and Figure 11, Figure 11 show and uses the circuit of Fig. 6, Fig. 9 to be entered
The analog waveform figure of row, wherein, curve 91 is the light modulation signal inputted, and its on-state rate
Being 10%, frequency is 600Hz, and curve 92 is that this light modulation signal shift circuit 5 is to floating
Light modulation input signal after ground voltage process, curve 93 is to reply module through this light modulation signal
The light modulation input signal after signal reply after 41 process, as seen from Figure 11, signal is replied
After the pulse bandwidth of this light modulation input signal (curve 93) and frequency be the most all same as this light modulation
Signal (curve 91).
Refering to Figure 12, reply another of module 41 for this light modulation signal in this first embodiment
Pattern, is at this pattern and the difference of this first embodiment:
This comparator 411 has a normal phase input end and an inverting input.
This light modulation signal is replied module 41 and is also had: sampling diode Dsh, a sampling
Electric capacity Csh, and a scheduled voltage Vf.
This sampling diode Dsh has an anode tap receiving this light modulation input signal, and one
The cathode terminal of this comparator 411 normal phase input end of individual electrical connection.
This sampling capacitor Csh has the of the cathode terminal of electrical connection this sampling diode Dsh
One end, and second end receiving this floating earth voltage.
This scheduled voltage Vf has one and electrically connects this comparator 411 inverting input and carry
For the first end of this predetermined voltage, and the of second end of electrical connection this sampling capacitor Csh
Two ends.
In this pattern, by adding this sampling diode Dsh and this sampling capacitor Csh, can
To provide sampling and to keep the effect of (Sample & Hold), it is to avoid when comparator 411 characteristic
Produce load effect time poor (input impedance is the biggest) and cause this light modulation input signal distortion.
Refering to Fig. 9, Figure 13 and Figure 14, wherein, Figure 13, Figure 14 show use Fig. 9,
The analog waveform figure that the circuit of Figure 12 is carried out, curve 91 is the light modulation signal inputted, song
Line 92 is light modulation input signal, and curve 93 is this light modulation input signal after signal reply, figure
In 13, the on-state rate of the light modulation signal of curve 91 is 90%, and frequency is 600Hz, bent in Figure 14
The on-state rate of the light modulation signal of line 91 is 10%, and frequency is 600Hz, by Figure 13 and Figure 14
Visible, after replying module 41 process via this light modulation signal shift circuit 5 and this light modulation signal,
The pulse bandwidth of this light modulation input signal (curve 93) after obtained signal reply and frequency are all
It is same as this light modulation signal (curve 91).
Via above explanation, the advantage of the present embodiment can be summarized as follows:
One, by using this dimming capacitors Cdim and this light modulation diode Ddim, can replace
Isolating transformer of the prior art or photo-coupler, not only can save in a large number circuit volume,
Reduce component, and then circuit cost is greatly reduced, and the present embodiment can apply to high-end opening
Close actuation techniques or floating earth mode, at the reference floating earth end VSS of control circuit 4
When the voltage of the floating earth voltage received and earth terminal differs, still can be in transmittance process
Do not have unified reference earthing potential can for reference in the case of normal detection or transmitting signals.
Two, can be learnt by Fig. 9, alternating current power supply Vac is being filtered through this power circuit 2 rectification
Ripple has transferred DC source to after processing, therefore input when the present embodiment DC voltage to be applied to
Time, only need to omit this power circuit 2, can be directly received by first end of this switch element Q1
The power signal of direct current, can increase the flexibility ratio in application.
Refering to Figure 15, for second embodiment of LED driving circuit of the present invention, it is somebody's turn to do
Second embodiment is analogous to the detailed circuit diagram of this first embodiment, this second embodiment with should
The difference of first embodiment is:
In this change-over circuit 3, this flywheel diode Do has this output electricity of an electrical connection
Hold the anode tap of first end of Co, and a cathode terminal；This inductance L has an electrical connection
First end of second end of this switch element Q1, and second end electrically connecting this earth terminal；
This feedback resistance Rfb is serially connected with the cathode terminal and the first of this inductance L of this flywheel diode Do
Between end.
In the present embodiment, falling-rising voltage conversion circuit (Buck-Boost Converter) is used
As explanation, but it is not limited to this.
Owing to the falling-rising pressure of this change-over circuit 3 is converted to known to this industry, and this control circuit
4 and the function mode of this light modulation signal shift circuit 5 be similar to above-mentioned, so the most superfluous at this
Speech.
So, this second embodiment also can reach the purpose identical with above-mentioned first embodiment and merit
Effect.
In sum, the present invention is possible not only to save circuit volume and cost, reduction design complexity
Degree, moreover it is possible to promote system dependability, the flexibility ratio increased in application, so really can reach this
The purpose of invention.
Claims (10)
1. a LED driving circuit, it is adaptable to drive multiple light emitting diode,
This LED driving circuit comprises a change-over circuit and a control circuit；
This change-over circuit includes a switch element, output capacitance, an inductance and
Individual flywheel diode；
This switch element have one receive the first end of a power signal, one second
End, and one receive one control signal control end, controlled and in conducting and cut-off between
Switching；
This output capacitance has one provides an output electric current to drive described light-emitting diodes
First end of pipe, and the second end of one earth terminal of an electrical connection；
It is characterized in that:
This inductance and this flywheel diode concatenation, and it is electrically connected to the first end of this output capacitance
And between earth terminal, and the junction point of this inductance and this flywheel diode is electrically connected to this switch unit
Second end of part also provides a floating earth voltage, and this inductance electrically connects this flywheel diode
Cathode terminal；
This control circuit include switch element control end, one with reference to floating earth end,
One light modulation signal input end, a light modulation signal reply module, a brightness adjustment control module；
This switch element controls end and electrically connects the control end of this switch element and provide this control
Signal；
This reference floating earth end is electrically connected to the junction point of this inductance and this flywheel diode,
To receive this floating earth voltage；
This light modulation signal input end is for receiving one to should the light modulation of floating earth voltage
Input signal；
This light modulation signal is replied module and is electrically connected this light modulation signal input end and this reference floating
Earth terminal, after receiving this light modulation input signal and this light modulation input signal being carried out signal reply
Output；
This brightness adjustment control module electrically connects this light modulation signal and replys module and this switch element control
End processed, receives this light modulation input signal after signal is replied, and according to this light modulation after replying
Input signal adjusts and exports this control signal；
This LED driving circuit also comprises a light modulation signal shift circuit, this light modulation
Signal shift circuit includes a light modulation diode and a dimming capacitors；
This light modulation diode has an anode tap receiving a light modulation signal, and one defeated
Go out the cathode terminal of this light modulation input signal；
This dimming capacitors has the first end of a cathode terminal electrically connecting this light modulation diode,
And second end receiving this floating earth voltage.
2. LED driving circuit as claimed in claim 1, it is characterised in that:
This light modulation signal is replied module and is had a comparator, and this comparator receives this light modulation input news
Number and compare with a predetermined voltage, with output signal reply after this light modulation input signal.
3. LED driving circuit as claimed in claim 2, it is characterised in that:
This light modulation signal replys this light modulation input signal after the signal reply that module is exported, its arteries and veins
Wave width and frequency are essentially the same as this light modulation signal.
4. LED driving circuit as claimed in claim 2, it is characterised in that:
This comparator has a normal phase input end and an inverting input；
This light modulation signal is replied module and is also had:
One sampling diode, has an anode tap receiving this light modulation input signal, and
One cathode terminal electrically connecting this comparator normal phase input end,
One sampling capacitor, has the first of a cathode terminal electrically connecting this sampling diode
End, and second end receiving this floating earth voltage, and
One scheduled voltage, has one and electrically connects this comparator inverting input and provide
First end of this predetermined voltage, and the second end of second end electrically connecting this sampling capacitor.
5. LED driving circuit as claimed in claim 2, it is characterised in that:
This LED driving circuit also comprises one and is somebody's turn to do with output for receiving an alternating current power supply
The power circuit of power signal, this alternating current power supply has first end and second end,
This power circuit includes a bridge rectifier module, and this bridge rectifier module has:
One the first diode, has the anode of first end electrically connecting this alternating current power supply
End, and the cathode terminal of first end electrically connecting this switch element,
One the second diode, has an anode tap electrically connecting this earth terminal, and one
Electrically connect the cathode terminal of the first end of this alternating current power supply,
One the 3rd diode, has the anode of second end electrically connecting this alternating current power supply
End, and the cathode terminal of first end electrically connecting this switch element, and
One the 4th diode, has an anode tap electrically connecting this earth terminal, and one
Electrically connect the cathode terminal of the second end of this alternating current power supply.
6. LED driving circuit as claimed in claim 5, it is characterised in that:
This power circuit also includes:
One filter capacitor, has the first of first end electrically connecting this switch element
End, and second end electrically connecting this earth terminal.
7. LED driving circuit as claimed in claim 6, it is characterised in that:
This power circuit also includes that one is electrically connected between this alternating current power supply and this bridge rectifier module
EMI Filtering module.
8. LED driving circuit as claimed in claim 7, it is characterised in that:
This EMI Filtering module has:
One EMI Filtering inductance, has first end electrically connecting this alternating current power supply
The first end, and second end of anode tap electrically connecting this first diode, and
One EMI Filtering electric capacity, has one and electrically connects this EMI Filtering inductance
The first end of the second end, and the second end of second end electrically connecting this alternating current power supply.
9. LED driving circuit as claimed in claim 1, it is characterised in that:
In this change-over circuit:
This flywheel diode has an anode tap electrically connecting this earth terminal, and electrical connection should
The cathode terminal of the second end of switch element,
This inductance has the first end of a cathode terminal electrically connecting this flywheel diode, and one
Second end of the first end of individual this output capacitance of electrical connection.
10. LED driving circuit as claimed in claim 1, it is characterised in that:
In this change-over circuit:
This flywheel diode has the anode tap of first end electrically connecting this output capacitance,
And electrically connect the cathode terminal of the second end of this switch element,
This inductance has the first end of a cathode terminal electrically connecting this flywheel diode, and one
Second end of individual this earth terminal of electrical connection.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW102132236 | 2013-09-06 | ||
| TW102132236A TWI489908B (en) | 2013-09-06 | 2013-09-06 | Light emitting diode drive circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104427716A CN104427716A (en) | 2015-03-18 |
| CN104427716B true CN104427716B (en) | 2016-11-30 |
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102932985A (en) * | 2011-08-12 | 2013-02-13 | 瑞鼎科技股份有限公司 | Light emitting diode driving device |
| CN103052226A (en) * | 2012-12-18 | 2013-04-17 | 深圳桑达国际电子器件有限公司 | LED (Light Emitting Diode) switching power supply and multimode dimming circuit thereof |
| CN203086787U (en) * | 2012-12-11 | 2013-07-24 | 欧司朗有限公司 | Led control circuit and led illuminating device |
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102932985A (en) * | 2011-08-12 | 2013-02-13 | 瑞鼎科技股份有限公司 | Light emitting diode driving device |
| CN203086787U (en) * | 2012-12-11 | 2013-07-24 | 欧司朗有限公司 | Led control circuit and led illuminating device |
| CN103052226A (en) * | 2012-12-18 | 2013-04-17 | 深圳桑达国际电子器件有限公司 | LED (Light Emitting Diode) switching power supply and multimode dimming circuit thereof |
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