WO2015051698A1

WO2015051698A1 - Led drive device

Info

Publication number: WO2015051698A1
Application number: PCT/CN2014/087273
Authority: WO
Inventors: 武俊; 文威
Original assignee: 欧普照明股份有限公司
Priority date: 2013-10-07
Filing date: 2014-09-24
Publication date: 2015-04-16
Also published as: CN203618180U

Abstract

The present utility model provides an LED drive device, comprising an input unit I, a rectification and filter unit II, a self-oscillating power supply unit III, a shutdown unit IV and an output unit V; the input unit I is used to input an alternating current voltage; the rectification and filter unit II is used to convert the alternating current voltage into a direct current voltage; the self-oscillating power supply unit III is used to convert the direct current voltage into a high-frequency direct current voltage; and the shutdown unit IV is connected to the self-oscillating power supply unit III and is used to shut down a switching element in the self-oscillating power supply unit III.

Description

LED driving device

Technical field

The utility model relates to the technical field of illumination, in particular to an LED driving device.

Background technique

Semiconductor lighting (LED) is a light source and display device for the third generation of semiconductor materials. It has the characteristics of low power consumption, long life, no pollution, rich color and strong controllability. It is a revolution in lighting source and light industry. With the development of LED, more and more LED lighting products are flooding into the market. The electronic drive part of the LED is an integral part of the LED lighting product.

Currently, ICs used in constant current LED driving circuits on the market are mainly driven by field effect transistors (MOSFETs). This scheme attempts to propose an IC for shutdown control, which does not directly drive the switching components, but uses the control method of turning off the switching components to realize the control of the driving circuit, so that the LED driver can use the triode as the switching component, which is currently in the field of lighting technology. One of the problems solved.

Utility model content

Currently, ICs used in constant current LED driving circuits on the market are mainly driven by field effect transistors (MOSFETs). The embodiment of the present invention attempts to propose an IC for shut-off control, which does not directly drive the switching element, but uses a control method of turning off the switching element to realize control of the driving line, so that the LED driving can use a triode as the switching element. The solution can improve the constant current precision of the LED driving circuit, realize a high power factor, realize a dimming function, and reduce the cost of the LED driver.

The technical solution of the present invention provides an LED driving device, comprising: an input unit I, a rectifying and filtering unit II, a self-oscillating power supply unit III, a shutdown unit IV and an output unit V, wherein:

Input unit I for AC voltage input;

a rectifying and filtering unit II connected to the input unit I for converting an alternating current voltage into a direct current voltage;

The self-oscillating power supply unit III is connected to the rectifying and filtering unit II for converting the DC voltage into a high-frequency DC voltage;

The shutdown unit IV is connected to the above self-oscillation power supply unit III for turning off the switching element (206) in the self-oscillation power supply unit III;

The output unit V is connected to the self-oscillation power supply unit III for filtering the high frequency DC voltage and supplying power to the load.

Preferably, the above-mentioned shutdown unit IV comprises a first acquisition component (411), a second acquisition component (422), a control component (433), a shutdown component (444), and a power supply component (455), wherein:

The first collecting component (411) is configured to collect a reference level signal;

The second collecting component (422) is configured to collect a level feedback signal;

The control component (433) is configured to compare the reference level signal of the first acquisition component (411) with the level feedback signal of the second acquisition component (422), and issue a corresponding control signal according to the comparison result;

The shut-off element (444) is configured to receive a control signal from the control element (433) to turn off the switching element (206) in the self-oscillation power supply unit III;

The power supply element (455) is configured to supply power to the shutdown element (444) and the control element (433).

Preferably, the self-excited oscillation power supply unit III includes a damping element (207), and the second acquisition element (422) is configured to collect a level feedback signal of the damping element (207).

Preferably, the control signal comprises: when the level feedback signal is greater than the reference level signal, the control component (433) generates a shutdown control signal to the shutdown component (444); and when the level feedback signal is less than the reference level signal Then, the above control element (433) does not generate a shutdown control signal.

Preferably, the above reference level signal is provided by an internal power supply of the chip or by an external power supply.

DRAWINGS

1 is a schematic structural view of an embodiment of the present invention;

2 is a schematic structural view of one embodiment of the present invention;

3 is a schematic structural view of a self-excited oscillation power supply unit according to an embodiment of the present invention;

4 is a schematic structural view of a shut-off unit according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a shutdown unit according to an embodiment of the present invention; FIG.

Figure 6 is a schematic structural view of the second embodiment of the present invention;

Figure 7 is a schematic structural view of the third embodiment of the present invention.

detailed description

Hereinafter, an LED driving device proposed by the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

The present scheme proposes an IC for shut-off control, which does not directly drive the switching element, but uses a control method of turning off the switching element to realize control of the driving line, so that the LED driving can use a triode as a switching element. It can be mainly used for self-oscillating LED driving circuit, which can improve the constant current precision of self-excited oscillation LED driving circuit, realize high power factor, realize dimming function, etc., thereby reducing the cost of LED driver and improving the competitiveness of LED product market.

1 is a schematic structural view of an embodiment of the present invention; FIG. 2 is a schematic structural view of one embodiment of the present invention;

An LED driving device comprises an input unit I, a rectifying and filtering unit II, a self-oscillating power supply unit III, an off unit IV and an output unit V, wherein:

Input unit I for AC voltage input;

The self-oscillating power supply unit III is connected to the rectifying and filtering unit II for converting the direct current voltage into a high frequency direct current voltage;

The turn-off unit IV is connected to the self-oscillating power supply unit III for turning off the self-oscillation power supply list Switching element 206 in element III.

The output unit V is connected to the self-oscillating power supply unit III for filtering the high frequency DC voltage and supplying power to the load.

3 is a schematic structural view of a self-oscillating power supply unit according to an embodiment of the present invention; wherein the self-oscillation power supply unit III includes a starting unit 311, a switching element 206, a damping element 207, and a power supply control unit 312.

The starting unit 311 includes a first resistor 201 and a first diode 202 connected in series. The first end of the first resistor 201 is connected to the rectifying and filtering unit II, and the second end of the first diode 202 is connected to the blocking unit IV. .

The switching element 206 and the damping element 207 are connected in series. The second end of the damping element 207 is connected to the switching unit IV, and the base and collector of the switching element 206 are connected to the power supply control unit 312.

4 is a schematic structural view of a shutdown unit according to an embodiment of the present invention, and FIG. 5 is a schematic structural diagram of a shutdown unit according to an embodiment of the present invention.

In an embodiment of the present invention, the shutdown unit IV includes:

The first acquisition component 411 is configured to acquire a reference level signal; the acquisition reference level signal may be provided by an internal power supply of the chip or by an external power supply.

a second collecting component 422: a level feedback signal for collecting the damping component 207 in the self-oscillating power supply unit III;

The control component 433 is configured to compare the reference level signal of the first acquisition component 411 with the level feedback signal of the second acquisition component 422, and issue a corresponding control signal according to the comparison result;

Further, in the present solution, if the level feedback signal is greater than the reference level signal, the control element 433 generates a shutdown control signal to the shutdown element 444. When the level feedback signal is less than the reference level signal, the control element 433 does not generate a shutdown control signal.

Shutdown element 444: for receiving the shutdown control signal from the control component 433, for self-excitation Turning off the switching element 206 in the power supply unit III;

Power supply element 455: for powering shutdown element 444 and control element 433. Among them, the power supply element 455 is obtained by acquiring power from an external power source.

Specifically, in the embodiment of the present invention:

In the startup phase, when the LED driving device of the present invention is connected to the DC input voltage DC, DC is discharged through the first resistor 201, the inductive component 203, and the base and emitter of the capacitive component 209 and the switching component 206. The current causes the switching element 206 to be turned on. The DC generates a current by discharging through the collector and emitter of the switching element 206 and the inductive element 203 and the capacitive element 209. Thereafter, the LED drive of the present invention enters the first energy storage stage.

In the first energy storage phase, current passes through the switching element 206, the inductive element 203, and the capacitive element 209. The inductive element 203 stores energy and generates a voltage across the two ends, while the inductive element 203 senses an induced electromotive force around the inductive element 203. The induced electromotive force is discharged by the first capacitor 204, the second resistor 205, and the base and the emitter of the switching element 206 to generate a current, so that the switching element 206 is in a saturated conduction state. The current flowing through the damping resistor 207 increases, and the voltage across the damping resistor 207 rises. When the voltage across the damping resistor 207 rises above the shutdown unit IV reference level signal, the shutdown unit IV operates, the base of the switching element 206 is shorted by the shutdown unit IV, and the switching element 206 is turned off. However, since the current flowing through the inductive element 203 cannot be abruptly changed, the current flows through the second diode 208 to the output for the capacitive element 209, and the voltage across the inductive element 203 is reversed. Thereafter, the semiconductor light source driving system of the present invention enters a phase of energy release.

In the release phase, the inductive electromotive force induced by the inductive element 203 on the sense element 203 is also reversed. The induced electromotive force is discharged by the first diode 202, the second resistor 205, and the first capacitor 204 to generate a current. The voltage across the inductive element 203 discharges the output capacitive element 209 through the second diode 208, and the inductive element 203 discharges. The current reverse charges the first capacitor 204 to produce a reverse voltage. When the voltage across the first capacitor 204 rises to the voltage across the inductive component 203, the energy release is stopped. Thereafter, the LED driving system of the present invention enters a second energy storage stage.

In the second energy storage phase, the voltage across the capacitive element 209 is discharged through the semiconductor light source LED load, and the voltage across the first capacitor 204 passes through the base and emitter of the switching element 206, the second resistor 205, and the secondary winding of the inductive component 203. The discharge generates a current to cause the collector and the emitter of the switching element 206 to be turned on. The DC generates a current by discharging the inductive element 203 and the collector and emitter of the capacitive element 209 and the switching element 206. The inductive element 203 begins to store energy, generating a voltage across it. Next, the auxiliary winding element 203 of the inductive element 203 induces an induced electromotive force, and the induced electromotive force is discharged through the first capacitor 204, the second resistor 205, and the base and the emitter of the switching element 206 to generate a current, so that the switching element 206 is at Saturated conduction. The current flowing through the damping resistor 207 increases, and the voltage across the damping resistor 207 rises. When the voltage across the damping resistor 207 rises above the shutdown unit IV reference level signal, the shutdown unit IV operates, the base of the switching element 206 is shorted by the shutdown unit IV, and the switching element 206 is turned off. However, since the current flowing through the inductive element 203 cannot be abruptly changed, the current flows through the second diode 208 to the output for the capacitive element 209, and the voltage across the inductive element 203 is reversed. Thereafter, the semiconductor light source driving system of the present invention again enters the energy release phase.

Then, the semiconductor light source driving system of the present invention re-enters the second energy storage phase from the energy release stage, and thus circulates.

Figure 6 is a schematic structural view of the second embodiment of the present invention; Figure 7 is a schematic structural view of the third embodiment of the present invention. Similarly, the input unit is used for the AC voltage input; the rectification and filtering unit is connected to the input unit for converting the AC voltage into a DC voltage; the self-oscillating power supply unit is connected to the rectification and filtering unit for converting the DC voltage into The high frequency DC voltage; the turn-off unit IV is connected to the self-oscillating power supply unit for turning off the switching element 206 in the self-oscillating power supply unit.

The output unit is connected to the self-oscillating power supply unit for filtering the high frequency DC voltage and supplying power to the load.

The above description of the preferred embodiments of the present invention is intended to be illustrative and not restrictive These modifications and variations are obvious to those skilled in the art and are intended to be included within the scope of the invention as defined by the appended claims.

Claims

An LED driving device, comprising: an input unit I, a rectifying and filtering unit II, a self-oscillating power supply unit III, an off unit IV and an output unit V, wherein:

Input unit I for AC voltage input;

a rectifying and filtering unit II connected to the input unit I for converting an alternating current voltage into a direct current voltage;

a self-oscillating power supply unit III connected to the rectifying and filtering unit II for converting the DC voltage into a high-frequency DC voltage;

The turn-off unit IV is connected to the self-oscillation power supply unit III for turning off the switching element (206) in the self-oscillation power supply unit III;

The output unit V is connected to the self-oscillation power supply unit III for filtering the high frequency DC voltage and supplying power to the load.
The LED driving device according to claim 1, wherein the shutdown unit IV comprises a first acquisition component (411), a second acquisition component (422), a control component (433), and a shutdown component (444). , power supply component (455), wherein:

The first acquisition component (411) is configured to collect a reference level signal;

The second collecting component (422) is configured to collect a level feedback signal;

The control component (433) is configured to compare a reference level signal of the first acquisition component (411) with a level feedback signal of the second acquisition component (422), and according to the comparison result Send corresponding control signals;

The shut-off element (444) is configured to receive a control signal from the control element (433) to turn off the switching element (206) in the self-oscillation power supply unit III;

The power supply element (455) is configured to supply power to the shutdown element (444) and the control element (433).
The LED driving device according to claim 2, wherein the self-oscillation power supply unit III includes a damping element (207), and the second acquisition element (422) is configured to collect the damping element (207) Level feedback signal.
The LED driving apparatus according to claim 2, wherein said control signal comprises: when said level feedback signal is greater than a reference level signal, said control element (433) generates a turn-off control signal to said turn-off Element (444); when the level feedback signal is less than the reference level signal, the control element (433) does not generate a shutdown control signal.
The LED driving device according to claim 2, wherein the reference level signal is provided by an internal power supply of the chip or by an external power source.