TWI551025B - Lighting power conversion device - Google Patents

Description

Lighting power conversion device

The present invention relates to a power conversion device, and more particularly to an illumination power conversion device capable of converting an AC input voltage into a DC output voltage for use by a light emitting diode unit.

Referring to Fig. 1, the conventional illumination power conversion device is composed of a boost type AC-DC converter 4 with a power-correcting function of the former stage and a half-bridge LLC resonant DC-DC converter 5 of the latter stage, due to the conventional The front and rear stages of the lighting power conversion device need to have a separate controller, so at least three power switches are needed to complete the lighting power conversion device. Therefore, the circuit is complicated and the number of components is also More, resulting in higher circuit costs.

Accordingly, it is an object of the present invention to provide an illumination power conversion apparatus that can make a circuit structure relatively simple and reduce the cost of the circuit.

Therefore, the illumination power conversion device of the present invention is adapted to be electrically connected between an input power source and a light emitting diode unit, and convert an AC input voltage from the input power source to generate a DC output voltage. For use in the light emitting diode unit, the lighting power conversion device includes an input unit, a transformer, a switch, an inductor, a capacitor, a first discharge diode, a second discharge diode, and an output unit.

The input unit is electrically connected to the input power to receive the input voltage, and is used for filtering noise and rectifying to generate a rectified voltage.

The transformer is electrically connected to the input unit to receive the rectified voltage, and includes a primary side winding having a first end and a second end, and a secondary side winding having a first end and a second end.

The switch includes a first end electrically connected to the second end of the primary side winding, and a second end, and the switch is controlled to switch between a conducting state and a non-conducting state.

The inductor includes a first end electrically coupled to the second end of the switch and a second end electrically coupled to the input unit.

The capacitor includes a first end and a second end electrically connected to the second end of the switch.

The first discharge diode includes an anode electrically connected to the second end of the inductor, and a cathode electrically connected to the first end of the capacitor.

The second discharge diode includes an anode electrically connected to the first end of the capacitor, and a cathode electrically connected to the first end of the primary side winding.

The output unit is coupled in parallel with the secondary winding and generates the output voltage to drive the LED unit.

The effect of the present invention is that an illumination power conversion device that requires at least three switches, such as a conventional one, can be completed with only one switch architecture, so that the number of component components is smaller and the circuit cost is lower.

1‧‧‧ input unit

11‧‧‧Filter circuit

12‧‧‧Rectifier circuit

2‧‧‧Transformers

3‧‧‧Output unit

4‧‧‧Boost AC-DC Converter

5‧‧‧DC-DC converter

6‧‧‧Input power supply

9‧‧‧Lighting diode unit

C‧‧‧ capacitor

Cr‧‧‧Resonance Capacitor

CO‧‧‧ output capacitor

D1‧‧‧First Rectifier Diode

D2‧‧‧Secondary rectifier diode

D3‧‧‧ third rectifier diode

D4‧‧‧4th rectifying diode

D5‧‧‧First discharge diode

D6‧‧‧Second discharge diode

D7‧‧‧ output diode

L‧‧‧Inductance

Lf‧‧‧Resonant Inductance

Lm‧‧‧Magnetic Inductance

n _p ‧‧‧ primary winding

n _s ‧‧‧secondary winding

S‧‧ switch

V _AC ‧‧‧ input voltage

V _REC (t)‧‧‧Rectified voltage

VO‧‧‧ output voltage

Other features and effects of the present invention will be apparent from the following description of the drawings. FIG. 1 is a flow chart illustrating one embodiment of a conventional illumination power conversion device; FIG. 2 is a circuit diagram illustrating An embodiment of the illumination power conversion device of the present invention; FIG. 3 is a timing diagram illustrating a timing pattern of the embodiment of the illumination power conversion device of the present invention; and FIG. 4 is a circuit diagram illustrating the implementation of the illumination power conversion device of the present invention. FIG. 5 is a circuit diagram illustrating a circuit diagram of the embodiment of the illumination power conversion device of the present invention in mode 2; and FIG. 6 is a circuit diagram illustrating the embodiment of the illumination power conversion device of the present invention in a mode Three circuit diagrams.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same reference numerals.

Referring to FIG. 2, an embodiment of the illumination power conversion device of the present invention is adapted to be electrically connected between an input power source 6 and a light-emitting diode unit 9, and convert an AC input voltage V _AC from the input power source 6. For generating a DC output voltage VO for use by the LED unit 9, and the illumination power conversion device includes an input unit 1, a transformer 2, a switch S, an inductor L, a capacitor C, and a first A discharge diode D5, a second discharge diode D6, and an output unit 3.

The input unit 1 is electrically connected to the input power source 6 to receive the input voltage V _AC , and is used for filtering noise and rectifying to generate a rectified voltage V _REC (t), and includes a filter circuit 11 and a rectifier circuit 12, The filter circuit 11 is electrically connected to the input power source 6 to receive the input voltage V _AC and used to filter out the noise of the input voltage V _AC to generate a filtered voltage (not shown). The rectifier circuit 12 is electrically connected to the filter. The circuit 11 receives the filtered voltage and rectifies the filtered voltage to obtain a pulsed DC rectified voltage V _REC (t).

The filter circuit 11 has a resonant inductor Lf and a resonant capacitor Cr. The resonant inductor Lf has a first end electrically connected to the input power source 6, and a second end, and the resonant capacitor Cr has an electrical connection. a first end of the second end of the resonant inductor Lf, and a second end.

The rectifier circuit 12 has a first rectifying diode D1, a second rectifying diode D2, a third rectifying diode D3, and a fourth rectifying diode D4.

The first rectifying diode D1 has an anode electrically connected to the first end of the resonant capacitor Cr, and a cathode.

The second rectifying diode D2 has a cathode electrically connected to the anode of the first rectifying diode D1, and an anode.

The third rectifying diode D3 has a cathode electrically connected to the cathode of the first rectifying diode D1, and an anode electrically connected to the second end of the resonant capacitor Cr.

The fourth rectifying diode D4 has a cathode electrically connected to the second end of the resonant capacitor Cr, and an electrical connection to the second rectifying diode The anode of the anode of D2.

The transformer 2 is electrically connected to the input unit 1 to receive the rectified voltage V _REC (t), and includes a primary side winding n _p and a secondary side winding n _s , the primary side winding n _p and the secondary side winding n _s Each has a first end and a second end, and the first end and the second end are a polarity point end and a non-polar point end, respectively.

The switch S includes a first end, a second end electrically connected to the second end of the primary side winding n _p , and a control end for switching between the conductive state and the non-conductive state, and in this embodiment The switch S is an N-type power semiconductor transistor, and the first end of the switch S is a drain, the second end is a source, and the control terminal is a gate.

The inductor L includes a first end electrically connected to the second end of the switch, and a second end electrically connected to the anode of the fourth rectifying diode D4 of the input unit 1.

The capacitor C includes a first end and a second end electrically connected to the second end of the switch S.

The first discharge diode D5 includes an anode electrically connected to the second end of the inductor L, and a cathode electrically connected to the first end of the capacitor C

The second discharge diode D6 includes an anode electrically connected to the first end of the capacitor, and a cathode electrically connected to the first end of the primary side winding n _p .

The output unit 3 is connected in parallel with the secondary winding n _s and generates the output voltage VO to drive the LED unit 9. The output unit 3 includes an output diode D7 and an output capacitor CO.

D7 anode having a second end electrically connected to the secondary winding of n _s, and a cathode of the output diode.

The output capacitor CO is connected in parallel to the LED unit 9 and has a first end electrically connected to the cathode of the output diode D7 and providing the output voltage, and a first end electrically connected to the secondary winding n _s The second end of one end.

Referring to FIG. 3, it is an operation timing diagram of the embodiment, wherein the parameters V _GS and V _DS are the voltage difference between the control end of the switch S and the second end and the first end and the second end, respectively. The parameters V _L and V _Lm represent the voltage across the inductor L and a magnetizing inductance Lm (not shown), respectively, and the parameters i _L and i _Lm represent the current flowing through the inductor L and the exciting inductor Lm, respectively, parameter i _D5 i _D6 and i _D7 represent currents flowing through the first discharge diode D5, the second discharge diode D6, and the output diode D7, respectively. According to the switching of the switch S, the embodiment will alternately drive the LED unit 9 in three modes, and the magnetizing inductance Lm of the transformer 2 will be drawn in the following modes in the following modes. The elements that are turned on are indicated by solid lines, and the elements that are not turned on by dashed lines. Each mode is described below for each mode, and it is assumed that the output capacitor CO and the capacitor C have completed the operation of storing energy in the third mode of the previous round.

Mode 1 (time: t0~t1): Referring to FIG. 4 at the same time, V _GS is a high potential at this time, so the switch S is in a conducting state, and the first discharging diode D5 is not conducting, so that the capacitor C Providing a current to form a current i _D6 flowing through the second discharge diode D6 via the second discharge diode D6 to charge the magnetizing inductance Lm, and a current related to the rectified voltage V _REC (t) also the magnetizing inductance Lm and the inductor L is charged via the switch S is turned on, thus the magnetizing inductance L current I _Lm and Lm is the inductor current i _L are linear rising trend.

However, a voltage across the secondary winding n _s at this time is still insufficient to turn on the output diode D7. Therefore, the output capacitor CO supplies the output voltage VO to drive the LED unit 9.

Mode 2 (time: t1~t2):

Referring also to FIG. 5, at this time, V _GS is a low potential, so the switch S is in a non-conducting state, and the second discharge diode D6 is also non-conducting. At this time, the inductor L provides a current through the first discharge. The diode D5 forms a current i _D5 flowing through the first discharge diode D5 to charge the capacitor C.

The magnetizing inductance Lm provides a current through the output diode D7 to form a current i _D7 flowing through the output diode _{D7 to} be discharged to the output capacitor CO and the light emitting diode unit 9.

Mode three (time: t2~t3):

Referring to FIG. 6, V _{GS is} still at the low potential, so the switch S is still in a non-conducting state, so the second discharge diode D6 is also not turned on, and the potential of the capacitor C and the potential of the inductor L at this time The potential difference does not make the first discharge diode D5 conductive, so the first discharge diode D5 turns non-conductive.

However, since the potential difference between the potential of the exciting inductor Lm and the potential of the output capacitor CO can still turn on the output diode D7, the exciting inductor Lm continuously supplies the current through the output diode D7 to flow through the output. The current i _{D7 of the} polar body D7 is discharged to the output capacitor CO and the light emitting diode unit 9, so that the light emitting diode unit 9 is continuously driven and the output capacitor CO is continuously charged. When the mode 3 ends, Go back to mode one.

In summary, the simple circuit architecture of the present embodiment requires only one switch S to achieve the same efficiency as the conventional AC-to-DC lighting power conversion device, and has the advantages of low circuit cost and power correction function. Therefore, the object of the present invention can be achieved.

The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications made by the patent application scope and patent specification content of the present invention, All remain within the scope of the invention patent.

1‧‧‧ input unit

11‧‧‧Filter circuit

12‧‧‧Rectifier circuit

2‧‧‧Transformers

3‧‧‧Output unit

6‧‧‧Input power supply

9‧‧‧Lighting diode unit

C‧‧‧ capacitor

Cr‧‧‧Resonance Capacitor

CO‧‧‧ output capacitor

D1‧‧‧First Rectifier Diode

D2‧‧‧Secondary rectifier diode

D3‧‧‧ third rectifier diode

D4‧‧‧4th rectifying diode

D5‧‧‧First discharge diode

D6‧‧‧Second discharge diode

D7‧‧‧ output diode

L‧‧‧Inductance

Lf‧‧‧Resonant Inductance

n _p ‧‧‧ primary winding

n _s ‧‧‧secondary winding

S‧‧ switch

V _AC ‧‧‧ input voltage

V _REC (t)‧‧‧Rectified voltage

VO‧‧‧ output voltage

Claims (10)

An illumination power conversion device is adapted to be electrically connected between an input power source and a light emitting diode unit, and convert an AC input voltage from the input power source to generate a DC output voltage for the The illumination power conversion device comprises: an input unit electrically connected to the input power to receive the input voltage, and used for filtering noise and rectifying to generate a rectified voltage; a transformer electrically connecting the The input unit receives the rectified voltage and includes a primary side winding having a first end and a second end, and a secondary side winding having a first end and a second end; a switch including an electrical connection a first end of the second end of the primary winding, and a second end, and the switch is controlled to switch between a conducting state and a non-conducting state; an inductor comprising a first end electrically connected to the second end of the switch And a second end electrically connected to the input unit; a capacitor comprising a first end, and a second end electrically connected to the second end of the switch; a first discharge diode An anode electrically connected to the second end of the inductor, and a cathode electrically connected to the first end of the capacitor; a second discharge diode including an anode electrically connected to the first end of the capacitor, and an electrical connection a cathode of the first end of the primary winding; and an output unit coupled in parallel with the secondary winding and generating the output voltage to drive the LED unit. The lighting power conversion device of claim 1, wherein the input sheet The element includes: a filter circuit electrically connected to the input power source to receive the input voltage, and configured to filter out noise of the input voltage to generate a filtered voltage; and a rectifying circuit electrically connected to the filter circuit to receive the filtered voltage And rectifying the filtered voltage to obtain a rectified voltage. The illumination power conversion device of claim 2, wherein the filter circuit has: a resonant inductor having a first end electrically connected to the input power source, and a second end; and a resonant capacitor having an electrical connection a first end of the second end of the resonant inductor, and a second end. The illumination power conversion device of claim 3, wherein the rectifier circuit has: a first rectifying diode having an anode electrically connected to the first end of the resonant capacitor, and a cathode; and a second rectifying diode a cathode having a cathode electrically connected to the first rectifying diode, and an anode; a third rectifying diode having a cathode electrically connected to the cathode of the first rectifying diode, and an electrical connection An anode of the second end of the resonant capacitor; and a fourth rectifying diode having a cathode electrically connected to the second end of the resonant capacitor and an anode electrically connected to the anode of the second rectifying diode. The illumination power conversion device of claim 4, wherein the output unit comprises: an output diode having an anode electrically connected to the second end of the secondary winding, and a cathode; and an output capacitor connected in parallel The light emitting diode unit has a first end electrically connected to the cathode of the output diode and providing the output voltage, and a second end electrically connected to the first end of the secondary side winding. The illumination power conversion device of claim 5, wherein when the switch is turned on, a current associated with the rectified voltage charges the transformer and the inductor via the switch, and the capacitor provides a current via the The two discharge diodes charge the transformer. The illumination power conversion device of claim 6, wherein when the switch is not conducting, the inductor provides a current to charge the capacitor via the first discharge diode, and the transformer provides a current via the output The diode is discharged to the output capacitor and the light emitting diode unit. The illumination power conversion device according to claim 7, wherein the first discharge diode is not turned on when the switch is not turned on and the potential difference between the potential of the capacitor and the potential of the inductor cannot turn on the first discharge diode The body is turned off, but the transformer continues to provide the current to be discharged to the output capacitor and the LED unit via the output diode. The illumination power conversion device of claim 1, wherein the primary side winding and the first end and the second end of the secondary side winding are a polarity point end and a non-polar point end, respectively. The lighting power conversion device of claim 1, wherein the switch is An N-type power semiconductor transistor, and the first end of the switch is a drain and the second end is a source.