TWI540940B - Power adjusting circuit - Google Patents

Description

Power adjustment circuit

The invention provides a power supply adjusting circuit, in particular to a power adjusting circuit for adjusting the luminous intensity of the light emitting module.

Solid-state illumination sources such as Light-Emitting Diodes (LEDs), Organic Light-Emitting Diodes (OLEDs), and Polymer Light Emitting Diodes (PLEDs) with input current And the characteristics of the input voltage is nonlinear. In detail, when the input voltage supplied by the drive circuit to the solid state illumination source is lower than the cut-in voltage of the solid state illumination source, the input current of the solid state illumination source is zero. When the input voltage supplied by the drive circuit to the solid state illumination source begins to rise above the cut-in voltage of the solid state illumination source, the input current of the solid state illumination source will increase rapidly as the input voltage increases.

Therefore, before the input voltage of the solid-state illumination source is lower than the cut-in voltage of the solid-state illumination source, the voltage provided by the driving circuit cannot make the solid-state illumination source emit light, and the illumination intensity of the solid-state illumination source cannot be adjusted, thereby causing the driving circuit to adjust the solid-state illumination. The order of the light source illumination intensity is reduced, and the dimming resolution is lowered.

The invention provides a power supply adjusting circuit for solving the driving The circuit can adjust the order of the luminous intensity of the solid-state illumination source to be reduced, and the dimming resolution is reduced.

The power supply adjusting circuit disclosed in the present invention is configured to generate a first driving voltage to drive the first lighting module. The power adjustment circuit includes a first power conversion module and a second power conversion module. The first power conversion module is configured to generate a voltage and a second converted electrical energy according to the first converted electrical energy. The second power conversion module is electrically connected to the first power conversion module. The second power conversion module is configured to output a portion of the second converted electrical energy at the first modulated voltage, and adjust a voltage level of the first modulated voltage according to the first control signal. The sum of the first driving voltage and the first modulation voltage. The voltage is less than the cut-in voltage of the first lighting module.

According to the power supply adjusting circuit disclosed in the present invention, the present invention uses the sum of the voltage and the first modulated voltage as the first driving voltage to drive the first lighting module. Since the voltage can make the first driving voltage of the first lighting module close to the cutting voltage of the first lighting module, only a small portion of the order of the first modulation voltage is used to make the first driving voltage The voltage level exceeds the voltage level of the cut-in voltage, and most of the order is used to adjust the voltage level of the first driving voltage to change the luminous intensity of the first light-emitting module. Accordingly, the present invention increases the order of adjusting the illumination intensity of the first illumination module, thereby improving the dimming resolution of the first illumination module.

The above description of the disclosure and the following description of the embodiments of the present invention are intended to illustrate and explain the spirit and principles of the invention, and to provide further explanation of the scope of the invention.

10, 20, 20a, 20b‧‧‧ power adjustment circuit

11, 21, 21a, 21b‧‧‧ first power conversion module

111, 211, 211a, 211b‧‧‧ AC to DC converter

1112, 2112a, 2112b‧‧‧ rectification unit

1114, 2114a, 2114b‧‧‧ first control unit

1116, 2116a, 2116b‧‧‧ first switch unit

113, 213, 213a~213b‧‧‧ capacitor

115, 215‧‧‧ first output

117, 217‧‧‧ second output

13, 23, 23a, 23b‧‧‧ second power conversion module

131, 231a, 231b, 251a, 251b‧‧‧ voltage generating unit

133, 233a, 233b, 253a, 253b‧‧‧ second control unit

135, 235a, 235b, 255a, 255b‧‧‧ second switching unit

25, 25a, 25b‧‧‧ third power conversion module

30‧‧‧Lighting module

40, 40a, 40b‧‧‧ first lighting module

50, 80a, 80b‧‧‧ AC power supply

60, 60a, 60b‧‧‧ second lighting module

Vdc, Vdc', Vdc_0, Vdc_a, Vdc_b‧‧‧ voltage

VLED‧‧‧ drive voltage

VLED1, VLED_1a, VLED_1b‧‧‧ first drive voltage

VLED2, VLED_2a, VLED_2b‧‧‧second driving voltage

Vac, Vac_a, Vac_b‧‧‧ AC voltage

Vin, V1_a, V2_a‧‧‧ input voltage

Vo, Vo’‧‧‧ modulated voltage

Vo1, Vo_1a, Vo_1b‧‧‧ first modulation voltage

Vo2, Vo_2a, Vo_2b‧‧‧ second modulation voltage

Vf, Vf', Vf1, Vf_1a, Vf_1b‧‧‧ cut-in voltage

Vf2, Vf_2a, Vf_2b‧‧‧ cut-in voltage

P1, P1_0‧‧‧ first conversion energy

P2, P2_0‧‧‧ second conversion energy

D1~D2, D5~D8, D3_a~D4_a, D3_b~D4_b‧‧‧ diode

R1~R3, R4_a~R5_a, R4_b~R5_b, R6~R7‧‧‧ resistor

C1, C2_a~C2_b, C3~C6‧‧‧ capacitor

Iin, I1_a, I2_a, I1_b, I2_b‧‧‧ input current

ILED _, ILED'‧‧‧ working current

ILED ₁ ‧‧‧First operating current

ILED ₂ ‧‧‧second operating current

Lp, Lp_1a, Lp_2a, Lp_1b, Lp_2b‧‧‧ primary side coil

Ls, Ls_1a, Ls_2a, Ls_1b, Ls_2b‧‧‧ secondary coil

Np1, Np2‧‧‧ primary side coil

Ns1, Ns2‧‧‧ secondary side coil

L1~L3‧‧‧Inductance

SC‧‧‧Control signal

SC1, SC_1a, SC_1b‧‧‧ first control signal

SC2, SC_2a, SC_2b‧‧‧ second control signal

SR, SF, SF_a, SF_b‧‧‧ feedback signals

SR_1a, SR_1b‧‧‧ first feedback signal

SR_2a, SR_2b‧‧‧ second feedback signal

FIG. 1 is a functional block diagram of a power supply adjusting circuit according to an embodiment of the invention.

FIG. 2 is a graph showing relationship between driving voltage and operating current according to an embodiment of the invention.

FIG. 3 is a graph showing driving voltage and operating current according to another embodiment of the present invention.

FIG. 4 is a circuit diagram of a power supply adjusting circuit according to an embodiment of the invention.

Figure 5 is a functional block diagram of a power supply adjusting circuit according to still another embodiment of the present invention.

Figure 6 is a circuit diagram of a power supply adjusting circuit according to still another embodiment of the present invention.

Figure 7 is a circuit diagram of a power supply adjusting circuit according to another embodiment of the present invention.

The detailed features and advantages of the present invention are set forth in the Detailed Description of the Detailed Description of the <RTIgt; </ RTI> <RTIgt; </ RTI> </ RTI> </ RTI> <RTIgt; The objects and advantages associated with the present invention can be readily understood by those skilled in the art. The following examples are intended to further illustrate the aspects of the invention, but not any The views limit the scope of the invention.

Referring to FIG. 1 to FIG. 3 , FIG. 1 is a functional block diagram of a power supply adjusting circuit according to an embodiment of the invention, and FIG. 2 is a driving voltage according to an embodiment of the invention. FIG. 3 is a graph showing relationship between driving voltage and operating current according to another embodiment of the present invention. As shown, the power conditioning circuit 10 is configured to generate the lighting module 30. The power adjustment circuit 10 has a first power conversion module 11 and a second power conversion module 13 . The first power conversion module 11 is configured to generate a voltage Vdc (such as, but not limited to, a fixed voltage) and a second converted power P2 according to the first converted power P1. The first converted electrical energy P1 may be provided by an external power supply, such as the illustrated AC power supply 50 or other suitable power supply. The first converted electrical energy P1 can be, for example, an alternating voltage Vac. The AC power supply 50 supplies an AC voltage Vac to the first power conversion module 11, and the first power conversion module 11 converts the AC voltage Vac into a voltage Vdc and a second converted power P2.

In the embodiment shown in FIG. 1, the first power conversion module 11 has an AC-to-DC converter 111 and a capacitor 113. The AC to DC converter 111 has a first output terminal 115 and a second output terminal 117. The potential difference between the first output terminal 115 and the second output terminal 117 of the AC-DC converter 111 is a voltage Vdc, and both ends of the capacitor 113 are electrically connected to the first output terminal 115 of the AC-DC converter 111 and the first The two output terminals 117 can be used to stabilize the potential difference between the first output terminal 115 and the second output terminal 117, so that the potential difference between the first output terminal 115 and the second output terminal 117 does not change much.

The second power conversion module 13 is electrically connected to the first output end 115 of the AC to DC converter 111, and the second power conversion module 13 is used to modulate the second converted power P2 generated by the AC to DC converter 111. The voltage Vo is output, and the voltage level of the modulation voltage Vo is adjusted according to the control signal SC. For example, the second converted electrical energy P2 can be the input current Iin, and the second electrical energy conversion module 13 is a DC-to-DC converter. The second power conversion module 13 converts the input current Iin, and outputs the converted input current Iin to the modulation voltage Vo, and adjusts the voltage level of the modulation voltage Vo according to the control signal SC. The second power conversion module 13 adjusts the voltage level of the modulation voltage Vo according to the control signal SC, for example, by means of Pulse Width Modulation (PWM), which will be described in detail later.

The voltage Vdc generated by the first power conversion module 11 and the modulation voltage Vo generated by the second power conversion module 13 are provided together to the light emitting module 30 for the light emitting module 30 to drive and adjust the luminous intensity. In other words, the sum of the voltage Vdc and the modulation voltage V0, that is, the driving voltage VLED outputted by the power supply adjusting circuit 10, is used to drive the light emitting module 30.

In one embodiment, the AC to DC converter 111 is a rectifying unit and a DC/DC converter. The DC-DC converter in the AC-to-DC converter 111 is a boost converter, a buck converter, a Buck-Boost Converter, and a return converter. The flyback converter or other suitable type of DC-to-DC converter is not limited in this embodiment. The second power conversion module 13 is also a boost converter, a buck converter, and a down/boost converter. Converter, flyback converter or other suitable type of DC to DC converter.

In this embodiment, the voltage level of the voltage Vdc is less than the voltage level of the cut-in voltage Vf of the light-emitting module 30, as shown in FIG. In other embodiments, the voltage level of the voltage Vdc' is equal to the voltage level of the cut-in voltage Vf of the light-emitting module 30, as shown in FIG. According to the relationship between the driving voltage and the operating current shown in FIG. 2, when the modulation voltage Vo is adjusted so that the sum of the voltage Vdc and the voltage Vdc is substantially equal to the cutting voltage Vf of the light-emitting module 30, the light-emitting module 30 starts to emit light. And as the modulation voltage Vo changes, the operating current ILED of the light-emitting module 30 increases. When the operating current ILED of the light-emitting module 30 increases, the luminous intensity of the light-emitting module 30 increases as the operating current ILED increases. Therefore, the luminous intensity of the light-emitting module 30 can be adjusted by adjusting the voltage level of the modulation voltage Vo.

However, those skilled in the art can understand that the cut-in voltage of the light-emitting module 30 generally refers to the voltage level point that the light-emitting module 30 is turned on, and the voltage level point that the light-emitting module 30 turns on is not necessarily as shown in FIG. The cut-in voltage Vf or the cut-in voltage Vf' is shown. When the voltage Vdc' is substantially equal to the cut-in voltage Vf' of the light-emitting module 30, the light-emitting module 30 increases as the modulation voltage Vo' provided by the second power conversion module 13 increases, thereby adjusting the light-emitting mode. The luminous intensity of group 30. Therefore, the voltage Vdc' referred to in this embodiment is smaller than the cut-in voltage Vf of the light-emitting module 30, and actually covers the technical range in which the voltage Vdc' is equal to the cut-in voltage Vf or the cut-in voltage Vf' of the light-emitting module 30.

In one embodiment, the upper limit of the modulation voltage Vo is related to the rated voltage of the light-emitting module 30, that is, the maximum input voltage that the light-emitting module 30 can tolerate. In more detail, the sum of the upper limit value of the modulation voltage Vo and the voltage Vdc is equal to the rated voltage of the light-emitting module 30. In addition, since the first power conversion module 11 is electrically connected to the second power conversion module 13 in this embodiment, the second power conversion module 13 outputs a portion of the second converted power P2 as the modulation voltage Vo. It can be considered that the second power conversion module 13 outputs all the second converted electric energy P2 with the modulation voltage Vo. All the second converted electric energy P2 referred to herein refers to an ideal case, and in actual operation, the first operation The two power conversion modules 13 will output some of the second converted power P2 before outputting the modulated voltage Vo.

For a clearer description, please refer to FIG. 4, which is a circuit diagram of a power supply adjusting circuit according to an embodiment of the invention. As shown in FIG. 4, the input end of the power supply adjusting circuit 10 is electrically connected to the AC power supply 50. The output end of the power adjustment circuit 10 is electrically connected to the light emitting module 30. The output of the power conditioning circuit 10 generates a driving voltage VLED to drive the lighting module 30.

The power adjustment circuit 10 has a first power conversion module 11 and a second power conversion module 13 . The first power conversion module 11 has an AC to DC converter 111 and a capacitor 113. The AC-to-DC converter 111 has a rectification unit 1112, a first control unit 1114, a first switching unit 1116, a primary side coil Lp, a diode D1, a resistor R1, and a resistor R2. The second power conversion module 13 has a voltage generating unit 131, a second control unit 133, a second switching unit 135, a diode D2, a capacitor C1, an inductor L1, and a resistor R3.

The rectifying unit 1112 rectifies the AC voltage Vac supplied from the AC power supply 50 to generate DC power. When the first switch unit When the 1116 is selectively turned on by the first control unit 1114, the DC supply power generated by the rectifying unit 1112 is supplied to the primary side coil Lp and the capacitor 113 to store the primary side coil Lp and the capacitor 113. When the first switching unit 1116 is selectively turned off by the first control unit 1114, the primary side coil Lp releases the stored electrical energy to the resistor R1 and the resistor R2, and maintains the voltage across the resistor R1 and the resistor R2 with the capacitor 113. Is the voltage Vdc.

When the primary side coil Lp in the first power conversion module 11 has a current, the secondary coil Ls in the second power conversion module 13 generates an input current Iin based on the principle of electromagnetic mutual inductance. The voltage generating unit 131 of the second power conversion module 13 generates an input voltage Vin according to the input current Iin. When the second switching unit 135 is selectively turned on by the second control unit 133, the input voltage Vin charges the capacitor C1 and the inductor L1. When the second switching unit 135 is selectively non-conducted by the second control unit 133, the inductor L1 and the capacitor C1 release the stored electric energy to adjust the potential difference between the capacitor C1 of the second electric energy conversion module 13 Voltage Vo.

In other words, in the case of the AC to DC converter 111, when the first switching unit 1116 is turned on, the AC power supply 50 supplies the AC voltage Vac to the rectifying unit 1112. The rectifying unit 1112 outputs electric energy via the current path PI1 in the drawing, and when the first switching unit 1116 is not turned on, the primary side coil Lp discharges electric energy via the current path PI2 in the drawing. The AC-to-DC converter 111 adjusts the conduction and non-conduction of the first switching unit 116 such that the average potential difference between the node N1 and the node N2 is the voltage Vdc.

In the second power conversion module 13, when the second switching unit 135 is turned on, the voltage generating unit 131 outputs power via the current path PI3 in the drawing, and when the second switching unit 135 is not turned on, the inductor L1 is in the figure. The current path PI4 releases electrical energy. The second power conversion module 13 adjusts the conduction and non-conduction of the second switching unit 135 so that the average potential difference between the node N3 and the node N4 is the modulation voltage Vo.

At this time, the light-emitting module 30 is electrically connected between the node N2 and the node N4, and the light-emitting module 30 is driven by the potential difference between the node N2 and the node N4. That is, the potential difference between the node N2 and the node N4 is the sum of the voltage Vdc generated by the alternating current to the direct current converter 111 and the modulated voltage Vo generated by the second power conversion module 13. The sum of the voltage Vdc and the modulation voltage Vo is used as the driving voltage VLED to drive the light emitting module 30.

On the other hand, in one embodiment, the modulation voltage Vo is modulated by providing the control signal SC to the second control unit 133, and the second control unit 133 adjusts the voltage level of the modulation voltage Vo according to the indication of the control signal SC. quasi. The control signal SC is an 8-bit number signal in a binary format, a 32-bit number signal in a hexadecimal format, or a signal in another suitable format, which is not limited in this embodiment. The control signal SC has a 256-order number to control the second power conversion module 13 to adjust the voltage level of the modulation voltage Vo.

In an embodiment, the 0th to 35th steps of the control signal SC indicate the voltage level of the modulation voltage Vo generated by the second control unit 133, and the voltage Vdc. The sum of the voltage levels does not cause the illumination module 30 to emit light. Starting from the 36th stage of the control signal SC, the voltage level of the modulation voltage Vo and the voltage Vdc is summed to start to illuminate the illumination module 30. Therefore, from the 36th to the 256th steps of the control signal SC, the voltage level sum of the modulation voltage Vo and the voltage Vdc can drive the illumination module 30 to emit light, and the illumination module 30 changes according to the class of the control signal SC. light intensity.

In more detail, when the control signal SC is at the 0th order, the modulation voltage Vo generated by the second power conversion module 13 is about 0 volts (Voltage, V), and the operating current ILED of the illumination module 30 is about 0 amps ( Ampere, A). When the control signal SC is at the 36th stage, the operating current ILED of the light-emitting module 30 begins to increase. When the control signal SC is at the 256th stage, the modulation voltage Vo generated by the second power conversion module 13 is about 10V, so that the operating current ILED of the light-emitting module 30 reaches the maximum current value, about 0.3A. Therefore, in this embodiment, the effective dimming order of the control signal SC is about 220 steps, and the voltage of each order modulation is about 0.045V, in other words, the least significant bit of the control signal SC (LSB) ) is equal to 0.45% of the adjustable voltage range.

In other embodiments, when the control signal SC is designed to be at the 0th order, the operating current ILED of the light-emitting module 30 begins to increase. When the control signal SC is at the 256th stage, the modulation voltage Vo generated by the second power conversion module 13 is about 10V, and the operating current ILED of the illumination module 30 is about 0.3A. At this time, the effective dimming order of the control signal SC is about 256 steps, and the voltage of each step modulation is about 0.039V, and the LSB of the control signal SC is equal to 0.39% of the adjustable voltage range, so as to achieve better resolution effect. .

In another embodiment, in addition to providing the control signal SC to the second control unit 133, the second control unit 133 can also adjust the voltage level of the modulation voltage Vo according to the feedback signal SR. . The feedback signal SR is related to the voltage level of the modulation voltage Vo. In the embodiment shown in Fig. 4, the feedback signal SR is generated based on the voltage across the resistor R3. Since the current flowing through the capacitor C1 also flows through the resistor R3. Therefore, the current flowing through the capacitor C1 causes the capacitor C1 to generate the modulation voltage Vo, and the same current flows through the resistor R3, so that the resistor R3 has a voltage across the voltage, so the feedback signal SR is related to the voltage level of the modulation voltage Vo. . By detecting the voltage across the resistor R3, the second control unit 133 further adjusts the voltage level of the modulation voltage Vo according to the voltage level of the current modulation voltage Vo, and allows the voltage level of the modulation voltage Vo to conform to the control. Signal SC indication.

In addition, in the first power conversion module 11, the first control unit 1114 can also adjust the voltage level of the voltage Vdc according to the feedback signal SF. In the embodiment shown in FIG. 4, the feedback signal SF is a voltage division generated by the resistor R1 and the resistor R2 according to the voltage output by the capacitor C1. In other words, the feedback signal SF is the voltage divider V1 and the resistor R2 are divided by the voltage Vdc. The voltage level is generated to cause the first power conversion module 11 to obtain the voltage level of the current voltage Vdc and adjust the voltage Vdc. The embodiment does not limit the manner in which the first power conversion module 11 and the second power conversion module 13 generate the feedback signal SF and the feedback signal SR, and does not limit the necessity of generating the feedback signal SF and the feedback signal SR. That is to say, in the embodiment shown in FIG. 4, the feedback signal SF and the feedback signal SR may be canceled to be sent to the first control unit 1114 and the second control unit 133.

Referring to FIG. 5, FIG. 5 is a functional block diagram of a power supply adjusting circuit according to still another embodiment of the present invention. As shown in FIG. 5, the power adjustment circuit 20 is configured to generate the first driving voltage VLED1 and the second driving voltage VLED2 to drive the first lighting module 40 and the second lighting module 60. The power adjustment circuit 20 includes a first power conversion module 21, a second power conversion module 23, and a third power conversion module 25. The first power conversion module 21 is configured to generate a voltage Vdc_0 and a second converted power P2_0 according to the first converted power P1_0 provided by the external AC power supply 80.

This embodiment is substantially the same as the embodiment shown in FIG. 1. For example, the first power conversion module 21 has an AC-to-DC converter 211 and a capacitor 213. The AC to DC converter 211 has a first output 215 and a second output 217. . The potential difference between the first output terminal 215 and the second output terminal 217 of the AC-to-DC converter 211 is a voltage Vdc_0, and the capacitor 213 is electrically connected between the first output terminal 215 and the second output terminal 217, and can be used to stabilize the first The potential difference between the output terminal 215 and the second output terminal 217 does not cause a large change in the potential difference between the first output terminal 215 and the second output terminal 217.

The first embodiment of the present embodiment is different from the embodiment shown in FIG. 1 . In this embodiment, the first output end 215 of the AC-to-DC converter 211 is electrically connected to the second power conversion module 23 . The third power conversion module 25 is connected. The second converted power P2_0 generated by the first power conversion module 21 is partially supplied to the second power conversion module 23, and the other portion is supplied to the third power conversion module 25.

The second power conversion module 23 is configured to convert a portion of the second converted electrical energy P2_0 is outputted by the first modulation voltage Vo1, and the voltage level of the first modulation voltage Vo1 is adjusted according to the first control signal SC1. The third power conversion module 25 is configured to output another portion of the second converted power P2_0 at the second modulation voltage Vo2, and adjust the voltage level of the second modulation voltage Vo2 according to the second control signal SC2. The voltage Vdc_0 generated by the first power conversion module 21 and the first modulation voltage Vo1 generated by the second power conversion module 23 are provided together to the first lighting module 40 for driving by the first lighting module 40, and The illumination intensity of the first illumination module 40 is changed by adjusting the first modulation voltage Vo1. The voltage Vdc_0 generated by the first power conversion module 21 and the second modulation voltage Vo2 generated by the third power conversion module 25 are provided together to the second lighting module 60 for driving by the second lighting module 60, and The illumination intensity of the second illumination module 60 is changed by adjusting the second modulation voltage Vo2. In other words, the sum of the voltage Vdc_0 and the first modulation voltage Vo1, that is, the first driving voltage VLED1 output by the power supply adjusting circuit 20, is used to drive the first lighting module 40. The sum of the voltage Vdc_0 and the second modulation voltage Vo2 is the second driving voltage VLED2 outputted by the power supply adjusting circuit 20 for driving the second lighting module 60.

In this embodiment, the voltage level of the voltage Vdc_0 provided by the first power conversion module 21 is smaller than the voltage level of the cut-in voltage Vf1 of the first light-emitting module 40 and the voltage level of the cut-in voltage Vt2 of the second light-emitting module 60. quasi. When the voltage level of the first modulation voltage Vo1 is adjusted to be equal to the sum of the voltage Vdc_0 substantially equal to the cut-in voltage Vf1 of the first light-emitting module 40, the first light-emitting module 40 starts to emit light, and along with the first modulation voltage Vo1 is changed, a first light-emitting module of the first change with operating current ILED ₁ 40, to adjust the light emission intensity of the first light emitting module 40 according to. When the voltage level of the second modulation voltage Vo2 is adjusted to be equal to the sum of the voltage Vdc_0 substantially equal to the cut-in voltage Vf2 of the second lighting module 60, the second lighting module 60 starts to emit light, and with the second modulation voltage The change of Vo2 causes the second operating current ILED _{2 of the} second lighting module 60 to change accordingly, thereby adjusting the luminous intensity of the second lighting module 60.

In one embodiment, the upper limit of the first modulation voltage Vo1 is related to the rated voltage of the first lighting module 40, that is, the maximum input voltage that the first lighting module 40 can tolerate. The upper limit value of the second modulation voltage Vo2 is related to the rated voltage of the second lighting module 60, that is, the maximum input voltage that the second lighting module 60 can tolerate. In more detail, the sum of the upper limit value of the first modulation voltage Vo1 and the voltage Vdc_0 is equal to the rated voltage of the first light emitting module 40. The sum of the upper limit value of the second modulation voltage Vo2 and the voltage Vdc_0 is equal to the rated voltage of the second lighting module 60.

In an ideal case, the power of the second converted power P2_0 generated by the first power conversion module 21 in this embodiment is substantially equal to the sum of the input powers of the second power conversion module 23 and the third power conversion module 25. In the actual operation, there is a partial power loss in the power conversion. Therefore, the power of the second converted power P2_0 is not completely equal to the second power conversion module 23 and the third power conversion module 25 due to the loss of the power conversion. The sum of the input powers should still be covered by the technical scope of the present invention.

In addition, in one embodiment, the maximum converted power value of the second power conversion module 23 or the maximum converted power value of the third power conversion module 25 is substantially equal to the power value of the second converted power P2_0. For example, the first electrical energy transfer The power of the second converted electrical energy P2_0 generated by the replacement module 21 may be 20 watts (Watt, W), wherein 15W is supplied to the first lighting module 40 and the second lighting module 60 with the voltage Vdc_0, and the other 5W is partially provided. The second power conversion module 23 performs power conversion by the second power conversion module 23, and another part of the 5W is supplied to the third power conversion module 25, and the third power conversion module 25 performs power conversion. In this example, the input power of the second power conversion module 23 and the third power conversion module 25 may be up to 5 W. Therefore, in this embodiment, the second power conversion module 23 and the third power conversion module 25 uses a converter with a maximum conversion power of 5W. In other words, in the embodiment, the power capacity requirements of the second power conversion module 23 and the third power conversion module 25 are small, so that the amount of conversion loss can be reduced, and the second power conversion module 23 and the third power conversion module 25 can be reduced. The volume occupied can also be reduced. The description that the power of the second converted electric energy P2_0 is 20 watts and the input power of the second electric energy conversion module 23 and the third electric energy conversion module 25 may be at most 5 W is for convenience of explanation and is not intended to limit the present invention. The way it can be implemented.

In a practical example, the first light emitting module 40 and the second light emitting module 60 may be composed of different numbers and colors of light emitting diodes. The first control signal SC1 and the second control signal SC2 for controlling the second power conversion module 23 and the third power conversion module 25 may be provided by the same control device or different control devices. The control device generates the first control signal SC1 and the second control signal SC2 according to the illumination intensity, color, color temperature or other requirements, so that the second power conversion module 23 and the third power conversion module 25 receive different powers. The second conversion power P2_0, and generates different first modulation voltage Vo1 and second modulation voltage Vo2, thus making the first hair The first driving voltage VLED1 and the second driving voltage VLED2 received by the optical module 40 and the second lighting module 60 are different. Thereby, the first lighting module 40 and the second lighting module 60 can generate different luminous intensities. The first light emitting module 40 and the second light emitting module 60 may separately provide light, or may be mixed to form light of various color temperatures or colors.

In other examples, the second power conversion module 23 and the third power conversion module 25 can also receive the second converted power P2_0, and generate different according to the first control signal SC1 and the second control signal SC2, respectively. The first modulation voltage Vo1 and the second modulation voltage Vo2 are not limited herein.

Please refer to FIG. 6. FIG. 6 is a schematic circuit diagram of a power supply adjusting circuit according to still another embodiment of the present invention. As shown in Fig. 6, the input end of the power supply adjusting circuit 20a is electrically connected to the AC power supply 80a. The first output end of the power supply adjusting circuit 20a is electrically connected to the first lighting module 40a, and the second output end is electrically connected to the second lighting module 60a. The first output terminal of the power adjustment circuit 20a generates a first driving voltage VLED_1a to drive the first lighting module 40a, and the second output generates a second driving voltage VLED_2a to drive the second lighting module 60a.

The power adjustment circuit 20a has a first power conversion module 21a, a second power conversion module 23a, and a third power conversion module 25a. The first power conversion module 21a has an AC-to-DC converter 211a and a capacitor 213a. The AC-to-DC converter 211a has a rectifying unit 2112a, a first control unit 2114a, a first switching unit 2116a, a primary side coil Lp_1a, a primary side coil Lp_2a, a diode D3_a, a diode D4_a, a capacitor C2_a, a resistor R4_a, and a resistor. R5_a. Second power conversion The module 23a has a voltage generating unit 231a, a second control unit 233a, a second switching unit 235a, a diode D5, a capacitor C3, an inductor L2, and a resistor R6. The third power conversion module 25a has a voltage generating unit 251a, a second control unit 253a, a second switching unit 255a, a diode D6, a capacitor C4, an inductor L3, and a resistor R7.

The rectifying unit 2112a rectifies the AC voltage Vac_a supplied from the AC power supply 80a to generate DC power. When the first switching unit 2116a is selectively turned on by the first control unit 2114a, the DC supply power generated by the rectifying unit 2112a is supplied to the primary side coil Lp_1a, the primary side coil Lp_2a, the capacitor 213a, and the capacitor C2_a. The primary side coil Lp_1a, the primary side coil Lp_2a, the capacitor 213a, and the capacitor C2_a are stored. When the first switching unit 2116a is selectively turned off by the first control unit 2114a, the primary side coil Lp_1a releases the stored electrical energy to the resistor R4_a and the resistor R5_a, and maintains the voltage across the resistor R4_a and the resistor R5_a with the capacitor 213a. Therefore, the voltage across the resistor R4_a and the resistor R5_a does not change much. The AC-to-DC converter 211a is adjusted in conduction and non-conduction by the first switching unit 2116a, so that the average potential difference across the capacitor 213a is the voltage Vdc_a. On the other hand, when the first switching unit 2116a is selectively turned off by the first control unit 2114a, the primary side coil Lp_2a, the capacitor C2_a and the diode D4_a form another loop, the primary side coil Lp_2a and The capacitor C2_a starts to release the stored electric energy, and the primary side coil Lp_2a has a current.

When the primary side coil Lp_1a and the primary side coil Lp_2a in the first power conversion module 21a have a current passing through, based on the principle of electromagnetic mutual inductance, the second electric The secondary side coil Ls_1a in the energy conversion module 23a generates an input current I1_a, and the secondary side coil Ls_2a in the third power conversion module 25a generates an input current I2_a. In the present embodiment, the secondary side coil Lp_1a and the secondary side coil Ls_1a in the second power conversion module 23a are not limited to one set, and the primary side coil Lp_2a and the secondary side coil Ls_2a in the third power conversion module 25a are not limited. A set, or the primary side coil Lp_1a and the secondary side coil Ls_2a in the third power conversion module 25a are a group, and the primary side coil Lp_2a and the secondary side coil Ls_1a in the second power conversion module 23a are a group. .

The voltage generating unit 231a of the second power conversion module 23a generates the input voltage V1_a according to the input current I1_a. When the second switching unit 235a is selectively turned on by the second control unit 233a, the input voltage V1_a charges the capacitor C3 and the inductor L2, and the potential of the capacitor C3 of the second power conversion module 23a has a potential difference. When the second switching unit 235a is selectively turned off by the second control unit 233a, the inductor L2 and the capacitor C3 release the stored electric energy, so that the capacitor C3 of the second electric energy conversion module 23a has a potential difference across the capacitor C3. The second power conversion module 23a is turned on and off by the second switching unit 235a, so that the average potential difference across the capacitor C3 is the first modulation voltage Vo_1a.

The voltage generating unit 251a of the third power conversion module 25a generates the input voltage V2_a according to the input current I2_a. When the second switching unit 255a is selectively turned on by the second control unit 253a, the input voltage V2_a charges the capacitor C4 and the inductor L3, so that both ends of the capacitor C4 have a potential difference. When the second switching unit 255a is selectively controlled to be non-conductive by the second control unit 253a, The sense L3 and the capacitor C4 release the stored electrical energy, so that both ends of the capacitor C4 have a potential difference. The third power conversion module 25a is turned on and off by the second switching unit 255a, so that the average potential difference across the capacitor C4 is the second modulation voltage Vo_2a.

The voltage Vdc_a generated by the first power conversion module 21a and the first modulation voltage Vo_1a generated by the second power conversion module 23a are supplied to the first light emitting module 40a for driving the first light emitting module 40a, and The illumination intensity of the first illumination module 40a is changed by adjusting the first modulation voltage Vo_1a. That is, the first light-emitting module 40a is electrically connected between the node N5_a and the node N6_a, and the potential difference between the node N5_a and the node N6_a is the voltage level sum of the voltage Vdc_a and the first modulation voltage Vo_1a, as the first A driving voltage VLED_1a drives the first lighting module 40a.

The voltage Vdc_a generated by the first power conversion module 21a and the second modulation voltage Vo_2a generated by the third power conversion module 25a are provided together to the second lighting module 60a for driving the second lighting module 60a. The illumination intensity of the second illumination module 60a is changed by adjusting the second modulation voltage Vo_2a. That is, the second light-emitting module 60a is electrically connected between the node N5_a and the node N7_a, and the potential difference between the node N5_a and the node N7_a is the voltage level sum of the voltage Vdc_a and the second modulation voltage Vo_2a, as the first The second driving voltage VLED_2a drives the second lighting module 60a. In addition, in this embodiment, the voltage level of the voltage Vdc_a provided by the first power conversion module 21a is smaller than the voltage level of the cut-in voltage Vf_1a of the first light-emitting module 40a and the cut-in voltage Vf_2a of the second light-emitting module 60a. Voltage level.

On the other hand, the second control unit 233a in one embodiment can adjust the voltage level of the first modulation voltage Vo_1a according to the first control signal SC_1a and the first feedback signal SR_1a. The first feedback signal SR_1a is related to the voltage level of the first modulation voltage Vo_1a. As shown in FIG. 6, the first feedback signal SR_1a is generated according to the voltage across the resistor R6. By detecting the voltage across the resistor R6, the second control unit 233a obtains the voltage level of the current first modulation voltage Vo_1a, and adjusts the voltage level of the first modulation voltage Vo_1a to make the first modulation voltage. The voltage level of Vo_1a can meet the indication of the first control signal SC_1a.

The second control unit 253a can adjust the voltage level of the second modulation voltage Vo_2a according to the second control signal SC_2a and the second feedback signal SR_2a. The second feedback signal SR_2a is related to the voltage level of the second modulation voltage Vo_2a. As shown in Fig. 6, the second feedback signal SR_2a is generated according to the voltage across the resistor R7. By detecting the voltage across the resistor R7, the second control unit 253a obtains the voltage level of the current second modulation voltage Vo_2a, and adjusts the voltage level of the second modulation voltage Vo_2a to make the second modulation voltage. The voltage level of Vo_2a can meet the indication of the second control signal SC_2a. In addition, in one embodiment, the first control unit 2114a in the first power conversion module 21a adjusts the voltage level of the voltage Vdc_a according to the feedback signal SF_a as in the embodiment of FIG. 4, and details are not described herein.

Please refer to FIG. 7. FIG. 7 is a schematic circuit diagram of a power supply adjusting circuit according to another embodiment of the present invention. As shown in FIG. 7, the power adjustment circuit 20b has a first power conversion module 21b, a second power conversion module 23b, and a third power conversion module 25b, wherein the first power conversion module 21b and the sixth figure The first power conversion modules 21a are shown to be substantially identical. Different from the embodiment shown in FIG. 6, the second power conversion module 23b and the third power conversion module 25b. The second power conversion module 23b includes a voltage generating unit 231b, a second control unit 233b, a second switching unit 235b, a primary side coil Np1, a secondary side coil Ns1, a diode D7, and a capacitor C5. The third power conversion module 25b includes a voltage generating unit 251b, a second control unit 253b, a second switching unit 255b, a primary side coil Np2, a secondary side coil Ns2, a diode D8, and a capacitor C6.

When the primary side coil Lp_1b and the primary side coil Lp_2b of the first power conversion module 21b have a current, the secondary side coil Ls_1b of the second power conversion module 23b generates an input current I1_b based on the principle of electromagnetic mutual inductance. The secondary side coil Ls_2b in the third power conversion module 25b generates an input current I2_b.

The voltage generating unit 231b in the second power conversion module 23b generates the input voltage V1_b according to the input current I1_b. When the second switching unit 235b is selectively turned on by the second control unit 233b, the voltage generating unit 231b, the second control unit 233b, and the primary side coil Np1 form a loop, and a current is formed on the primary side coil Np1. At this time, based on the principle of electromagnetic mutual inductance, an induced current is generated on the secondary side coil Ns1, and a potential difference is formed across the capacitor C5. When the second switching unit 235b is selectively turned off by the second control unit 233b, the secondary side coil Ns1 releases the stored electric energy so that both ends of the capacitor C5 have a potential difference. The second power conversion module 23b is turned on and off by the second switching unit 235b, so that the average potential difference between the two ends of the capacitor C5 is the first modulation voltage Vo_1b, and the capacitor C5 is used to make the first modulation voltage Vo_1b The voltage level will not change much Amplitude.

The voltage generating unit 251b in the third power conversion module 25b generates an input voltage V2_b according to the input current I2_b. When the second switching unit 255b is selectively turned on by the second control unit 253b, the voltage generating unit 251b, the second control unit 253b, and the primary side coil Np2 form a loop, and a current is formed on the primary side coil Np2. At this time, based on the principle of electromagnetic mutual inductance, an induced current is generated on the secondary side coil Ns2, and both ends of the capacitor C6 have a potential difference. When the second switching unit 255b is selectively turned off by the second control unit 253b, the secondary side coil Ns2 discharges the stored electric energy so that both ends of the capacitor C6 have a potential difference. The third power conversion module 25b is turned on and off by the second switching unit 255b, so that the average potential difference between the two ends of the capacitor C6 is the second modulation voltage Vo_2b, and the capacitor C6 is used to make the second modulation voltage Vo_2b The voltage level does not change much.

In the second power conversion module 23b, the second control unit 233b controls the length of the second switching unit 235b and the number of turns of the primary side coil Np1 and the secondary side coil Ns1 to adjust the first modulation voltage. The voltage level of Vo_1b. Further, in the third power conversion module 25b, the second control unit 253b controls the length of the on-time of the second switching unit 255b and the number of turns of the primary side coil Np2 and the secondary side coil Ns2 to adjust the second modulation voltage Vo_2b. The voltage level.

The voltage Vdc_b generated by the first power conversion module 21b and the first modulation voltage Vo_1b generated by the second power conversion module 23b are supplied to the first light emitting module 40b for driving by the first light emitting module 40b, and To adjust the first modulation The voltage Vo_1b changes the luminous intensity of the first light emitting module 40b. That is, the first light-emitting module 40b is electrically connected between the node N5_b and the node N6_b, and the potential difference between the node N5_b and the node N6_b is the voltage level sum of the voltage Vdc_b and the first modulation voltage Vo_1b, as the first A driving voltage VLED_1b drives the first lighting module 40b. The voltage Vdc_b generated by the first power conversion module 21b and the second modulation voltage Vo_2b generated by the third power conversion module 25b are provided together to the second lighting module 60b for driving by the second lighting module 60b, and The illumination intensity of the second illumination module 60b is changed by adjusting the second modulation voltage Vo_2b. That is, the second light-emitting module 60b is electrically connected between the node N5_b and the node N7_b, and the potential difference between the node N5_b and the node N7_b is the voltage level sum of the voltage Vdc_b and the second modulation voltage Vo_2b, as the first The second driving voltage VLED_2b drives the second lighting module 60b. In this embodiment, the voltage level of the voltage Vdc_b provided by the first power conversion module 21b is smaller than the voltage level of the cut-in voltage Vf_1b of the first light-emitting module 40b and the voltage level of the cut-in voltage Vf_2b of the second light-emitting module 60b. quasi.

In one embodiment, the first control unit 2114b of the first power conversion module 21b adjusts the voltage level of the voltage Vdc_b according to the feedback signal SF_b as in the embodiment of FIG. 4, and details are not described herein. The second control unit 233b in one embodiment can adjust the voltage level of the first modulation voltage Vo_1b according to the first control signal SC_1b and the first feedback signal SR_1b. The first feedback signal SR_1b directly adjusts the voltage level of the first modulation voltage Vo_1b by detecting the voltage level of the first driving voltage VLED_1b on the first lighting module 40b.

The second control unit 253b can be based on the second control signal SC_2b and the The second feedback signal SR_2b adjusts the voltage level of the second modulation voltage Vo_2b. The second feedback signal SR_2b directly adjusts the voltage level of the second modulation voltage Vo_2b by detecting the voltage level of the second driving voltage VLED_2b on the second lighting module 60b.

In summary, the present invention utilizes the sum of the voltage and the first modulation voltage as the first driving voltage to drive the first lighting module. Since the voltage can make the first driving voltage of the first lighting module close to the cutting voltage of the first lighting module, only a small portion of the order of the first modulation voltage is used to make the first driving voltage The voltage level exceeds the voltage level of the cut-in voltage, and most of the order is used to adjust the voltage level of the first driving voltage to change the luminous intensity of the first light-emitting module. Accordingly, the present invention not only increases the order of adjusting the illumination intensity of the first illumination module, but also improves the dimming resolution of the first illumination module, and also reduces the electrical energy required to be converted by the second electrical energy conversion module. Therefore, the loss caused by the power conversion is reduced, and the overall benefit of the power adjustment circuit of the present invention is improved.

Although the present invention has been disclosed above in the foregoing embodiments, it is not intended to limit the invention. It is within the scope of the invention to be modified and modified without departing from the spirit and scope of the invention. Please refer to the attached patent application for the scope of protection defined by the present invention.

10‧‧‧Power adjustment circuit

11‧‧‧First power conversion module

111‧‧‧AC to DC converter

113‧‧‧ Capacitance

115‧‧‧ first output

117‧‧‧second output

13‧‧‧Second power conversion module

30‧‧‧Lighting module

50‧‧‧AC power supply

P1‧‧‧First conversion energy

P2‧‧‧Second conversion energy

Vdc‧‧‧ voltage

VLED‧‧‧ drive voltage

Vo‧‧‧ modulation voltage

SC‧‧‧Control signal

Claims (11)

A power adjustment circuit for generating at least one first driving voltage to drive a first lighting module, the power conditioning circuit comprising: a first power conversion module for generating a voltage according to a first converted electrical energy a second conversion power; and a second power conversion module electrically connected to the first power conversion module, configured to output a portion of the second converted power to a first modulated voltage, and according to a first Controlling a signal, adjusting a voltage level of the first modulation voltage; wherein the first driving voltage is a sum of the voltage and the first modulation voltage, and the voltage is less than a cut-in voltage of the first lighting module. The power conditioning circuit of claim 1, wherein the first power conversion module comprises an AC to DC converter and a capacitor, the AC to DC converter comprising a first output end and a second output end, The capacitor is electrically connected between the first output end and the second output end, and the second power conversion module is electrically connected to the first output end. The power adjustment circuit of claim 2, wherein the AC to DC converter adjusts the voltage according to a first feedback signal, the first feedback signal being related to a voltage output by the capacitor. The power adjustment circuit of claim 2, further comprising a third power conversion module electrically connected to the first output of the AC to DC converter, the AC to DC converter providing another portion of the second conversion Power to the third power conversion module, the third power conversion module is configured to receive the second converted power The second modulation voltage output. The power adjustment circuit of claim 4, wherein the third power conversion module adjusts a voltage level of the second modulation voltage according to a second control signal, and a sum of the voltage and the second modulation voltage A second driving voltage is used to drive a second lighting module. The power supply adjusting circuit of claim 5, wherein an upper limit value of the first driving voltage is associated with a rated voltage of the first lighting module, and an upper limit value of the second driving voltage is associated with the second lighting mode The rated voltage of the group. The power adjustment circuit of claim 5, wherein the voltage is less than a cut-in voltage of the first light-emitting module and a cut-in voltage of the second light-emitting module. The power adjustment circuit of claim 5, wherein the input power of the second power conversion module and the input power of the third power conversion module are substantially equal to the power of the second converted power. The power adjustment circuit of claim 5, wherein the maximum conversion power of the second power conversion module or the maximum conversion power of the third power conversion module is substantially equal to the power of the second converted power. The power adjustment circuit of claim 1, wherein the second power conversion module further adjusts the first modulation voltage according to a second feedback signal and the first control signal, wherein the second feedback signal is related to the The first modulation voltage. The power conditioning circuit of claim 1, wherein the voltage is a fixed voltage.