An adaptive dimming circuit

Abstract

The present invention relates to the technical field of LED lighting, and discloses an adaptive dimming circuit with relatively stable signal switching and high reliability, including a power driving circuit (203), a DC filtering circuit (300), a first dimming circuit (700), a first optocoupler (500), a second dimming circuit (800) and a second optocoupler (600); when the signal value of the first control signal is less than that of the second control signal, the power driving circuit (203) adjusts the brightness of the lamp (400) according to the first control signal output by the first dimming circuit (700); when the signal value of the first control signal is greater than that of the second control signal, the power driving circuit (203) adjusts the brightness of the lamp (400) according to the second control signal output by the second dimming circuit (800).

Description

Technical Field

[0001] The present invention relates to the technical field of LED lighting, and more specifically, to an adaptive dimming circuit. Background Art

[0002] LED dimming circuits are relatively common power circuits in industry or households. Currently, the existing two-in-one or multi-in-one dimming power supplies on the market usually use a single-chip microcomputer to process two or more output dimming signals. After the dimming signals are integrated and processed by the single-chip microcomputer, a dimming signal is output to control the output of the LED power supply, thereby achieving dimming. However, during the signal processing process, it is necessary to convert between digital and analog signals, and signal conversion errors and processing time delays may occur during this process, thereby affecting the dimming effect; moreover, the above dimming circuit requires the cooperation of hardware and software, resulting in a relatively high manufacturing cost.

[0003] Therefore, how to avoid signal conversion errors and processing time delays to ensure the dimming effect has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an adaptive dimming circuit with relatively stable signal switching and high reliability in view of the above-mentioned defect that in the prior art, signal conversion between digital and analog signals is required during the signal processing process, and signal conversion errors and processing time delays may occur during this process, thereby affecting the dimming effect.

[0005] The technical solution adopted by the present invention to solve its technical problems is to construct an adaptive dimming circuit, comprising:

[0006] A power driving circuit, which is arranged in the dimming circuit and is used for outputting a driving signal;

[0007] A DC filtering circuit, whose input end is coupled to the output end of the power driving circuit, is used for receiving the driving signal input by the power driving circuit, and the driving signal is used for controlling the working state of the lamp;

[0008] A first dimming circuit, one signal input end of which is connected to the output end of the dimming controller, is used for receiving a first regulation signal;

[0009] A first optocoupler, whose input end is coupled to the output end of the first dimming circuit, is used for receiving the first regulation signal;

[0010] A second dimming circuit, one signal input end of which is connected to the output end of the dimming controller, is used for receiving a second regulation signal;

[0011] A second optocoupler, whose input end is coupled to the output end of the second dimming circuit, is used for receiving the second regulation signal; wherein,

[0012] The signal input terminals of the power driving circuit are respectively connected to the output terminals of the first opto-coupler and the second opto-coupler, and are used for receiving the first regulation signal and the second regulation signal;

[0013] When the signal value of the first regulation signal is less than that of the second regulation signal, the power driving circuit adjusts the brightness of the lamp according to the first regulation signal output by the first dimming circuit;

[0014] When the signal value of the first regulation signal is greater than that of the second regulation signal, the power driving circuit adjusts the brightness of the lamp according to the second regulation signal output by the second dimming circuit.

[0015] In some embodiments, the first opto-coupler and the second opto-coupler connected in parallel are connected in series with the input terminal of the power driving circuit.

[0016] In some embodiments, the power driving circuit includes a first controller, and the input terminals of the first controller are respectively connected to the output terminals of the first opto-coupler and the second opto-coupler.

[0017] In some embodiments, the first dimming circuit includes a tangent signal input circuit and a first control circuit,

[0018] The signal input terminal of the tangent signal input circuit is coupled to the output terminal of the dimming controller for receiving the first regulation signal,

[0019] The input terminal of the first control circuit is connected to the output terminal of the tangent signal input circuit,

[0020] The output terminal of the first control circuit is coupled to the signal input terminal of the first opto-coupler.

[0021] In some embodiments, the first control circuit includes a first amplifier and a first output voltage sampling and voltage dividing circuit. The non-inverting input terminal of the first amplifier is connected to the output terminal of the tangent signal input circuit for receiving the first regulation signal,

[0022] The inverting input terminal of the first amplifier is connected to the output terminal of the first output voltage sampling and voltage dividing circuit for receiving a voltage signal,

[0023] The output terminal of the first amplifier is connected to the signal input terminal of the first opto-coupler.

[0024] In some embodiments, the second dimming circuit includes a 0-10V signal input circuit and a second control circuit,

[0025] The signal input terminal of the 0-10V signal input circuit is coupled to the output terminal of the dimming controller for receiving the second regulation signal.

[0026] The input terminal of the second control circuit is connected to the output terminal of the 0-10V signal input circuit.

[0027] The output terminal of the second control circuit is coupled to the signal input terminal of the second opto-coupler.

[0028] In some embodiments, the second control circuit includes a second amplifier and a second output voltage sampling and voltage dividing circuit. The non-inverting input terminal of the second amplifier is connected to the output terminal of the 0-10V signal input circuit for receiving the second regulation signal.

[0029] The inverting input terminal of the second amplifier is connected to the output terminal of the second output voltage sampling and voltage dividing circuit for receiving a voltage signal.

[0030] The output terminal of the second amplifier is connected to the signal input terminal of the second opto-coupler.

[0031] In some embodiments, a transformer isolation circuit is further included. One end of the transformer isolation circuit is connected to the output terminal of the power drive circuit.

[0032] The output terminal of the transformer isolation circuit is coupled to the input terminal of the DC filtering circuit.

[0033] In some embodiments, a constant voltage / constant current circuit is further included. One input terminal of the constant voltage / constant current circuit is connected to the output terminal of the DC filtering circuit.

[0034] The other input terminal of the constant voltage / constant current circuit is connected to the 2.5V power supply terminal.

[0035] The output terminal of the constant voltage / constant current circuit is coupled to the input terminal of the power drive circuit.

[0036] In some embodiments, the constant voltage / constant current circuit includes a third amplifier and a third opto-coupler.

[0037] The non-inverting input terminal of the third amplifier is connected to the 2.5V power supply terminal.

[0038] The inverting input terminal of the third amplifier is connected to the output terminal of the DC filtering circuit.

[0039] One end of the third opto-coupler is coupled to the output terminal of the third amplifier.

[0040] The output terminal of the third opto-coupler is coupled to the input terminal of the power drive circuit.

[0041] In the adaptive dimming circuit of the present invention, it includes a power driving circuit, a DC filtering circuit, a first dimming circuit, a first opto-coupler, a second dimming circuit, and a second opto-coupler. Among them, the signal input terminals of the power driving circuit are respectively connected to the output terminals of the first opto-coupler and the second opto-coupler, and it is used to receive a first regulation signal and a second regulation signal; when the signal value of the first regulation signal is less than that of the second regulation signal, the power driving circuit adjusts the brightness of the lamp according to the first regulation signal output by the first dimming circuit; when the signal value of the first regulation signal is greater than that of the second regulation signal, the power driving circuit adjusts the brightness of the lamp according to the second regulation signal output by the second dimming circuit. Compared with the prior art, the first opto-coupler and the second opto-coupler are respectively arranged in the two dimming circuits, and the power driving circuit selects the one with the lower signal value among the regulation signals output by the first opto-coupler and the second opto-coupler to adjust the brightness of the lamp. During the control process, the other party does not affect its normal operation, so as to realize adaptive dimming in two dimming modes, which can effectively solve the problems that when using a single-chip microcomputer to process signals, there are errors in signal conversion and processing time delay, thus affecting the dimming effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The present invention will be further described below in conjunction with the drawings and embodiments. In the drawings:

[0043] Figure 1 is a framework diagram of an embodiment of the adaptive dimming circuit provided by the present invention;

[0044] Figure 2 is a circuit schematic diagram of an embodiment of the power factor correction, power driving circuit, and transformer isolation circuit provided by the present invention;

[0045] Figure 3 is a circuit schematic diagram of an embodiment of the DC filtering circuit provided by the present invention;

[0046] Figure 4 is a circuit schematic diagram of an embodiment of the first dimming circuit provided by the present invention;

[0047] Figure 5 is a circuit schematic diagram of an embodiment of the second dimming circuit provided by the present invention;

[0048] Figure 6 is a circuit schematic diagram of an embodiment of the constant voltage / constant current circuit provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0049] In order to have a clearer understanding of the technical features, objectives, and effects of the present invention, the specific embodiments of the present invention will now be described in detail with reference to the drawings.

[0050] As Figures 1-6As shown, in the first embodiment of the adaptive dimming circuit of the present invention, the adaptive dimming circuit 10 includes an AC / DC filtering circuit 100, a power factor correction, power driving circuit and transformer isolation circuit 200 (including a power driving circuit 203), a DC filtering circuit 300, a first optocoupler 500, a second optocoupler 600, a first dimming circuit 700, and a second dimming circuit 800.

[0051] Among them, the AC / DC filtering circuit 100 is used to receive the voltage on the mains side, and after rectification and filtering, it outputs to the power factor correction, power driving circuit and transformer isolation circuit 200 and the first dimming circuit 700 respectively.

[0052] The power factor correction, power driving circuit and transformer isolation circuit 200 includes:

[0053] A power factor correction circuit 201, which is used to detect and calculate the power factor when the AC / DC filtering circuit 100 is working;

[0054] A transformer isolation circuit 202, which is used to receive the current / voltage signal output by the AC / DC filtering circuit 100 and step down the current / voltage signal to output a voltage suitable for the operation of the subsequent circuit;

[0055] A power driving circuit 203, which is used to receive a control signal and perform dimming control on the lamp 400 according to the input control signal.

[0056] The DC filtering circuit 300 is used to receive the driving signal or control signal output by the power factor correction, power driving circuit and transformer isolation circuit 200. Among them, the driving signal is used to trigger the lamp 400, and the control signal is used to adjust the brightness when the lamp 400 is working.

[0057] The first dimming circuit 700 is used to receive the first control signal (or LED power tangent signal) input by a tangent controller (belonging to a front-edge tangent or trailing-edge tangent dimmer, not shown), and process the input first control signal (or LED power tangent signal) (adjust its voltage).

[0058] The first optocoupler 500 has an isolation function. It is used to receive the first control signal (or LED power tangent signal) processed by the first dimming circuit 700 and then output it to the power driving circuit 203.

[0059] The second dimming circuit 800 is used to receive the second control signal (or 0-10V signal) input by a dimming controller (corresponding to an MCU), and process the input second control signal (or 0-10V signal) (adjust its voltage).

[0060] The second opto-coupler 600 has an isolation function. It is used to receive the second regulation signal (or 0-10V signal) processed by the second dimming circuit 800 and then output it to the power drive circuit 203.

[0061] Specifically, as Figure 2 shown, the power drive circuit 203 is configured in the adaptive dimming circuit and is used to receive the voltage signal output by the previous-stage circuit (corresponding to the AC-DC filtering circuit 100). After being processed by the power drive circuit 203, it forms a drive signal that can be used to control the conduction or shutdown of the lamp 400.

[0062] Furthermore, the input end of the DC filtering circuit 300 is coupled to the output end of the power drive circuit 203 and is used to receive the drive signal input by the power drive circuit 203. The drive signal is used to control the working state of the lamp 400.

[0063] Specifically, power is supplied to the AC-DC filtering circuit 100, and the power factor correction, power drive circuit, transformer isolation circuit 200, DC filtering circuit 300, and lamp 400 are powered on and start to work. At this time, both the first dimming circuit 700 and the second dimming circuit 800 are at the maximum value, the output of the DC filtering circuit 300 is at the maximum value, and the state of the lamp 400 (corresponding to LED1--LEDN) is the brightest.

[0064] At this time, neither the first dimming circuit 700 nor the second dimming circuit 800 is connected to the dimming controller (corresponding to the MCU).

[0065] Furthermore, one signal input end of the first dimming circuit 700 is connected to the output end of the dimming controller (corresponding to the MCU) and is used to receive the first regulation signal, process the first regulation signal, and then output it to the first opto-coupler 500.

[0066] The input end of the first opto-coupler 500 is coupled to the output end of the first dimming circuit 700 and is used to receive the first regulation signal and output the first regulation signal to the power drive circuit 203.

[0067] One signal input end of the second dimming circuit 800 is connected to the output end of the dimming controller (corresponding to the MCU) and is used to receive the second regulation signal, process the second regulation signal, and then output it to the second opto-coupler 600.

[0068] The input end of the second opto-coupler 600 is coupled to the output end of the second dimming circuit 800 and is used to receive the second regulation signal and output the second regulation signal to the power drive circuit 203.

[0069] Specifically, the signal input terminals of the power driving circuit 203 are respectively connected to the output terminals of the first opto-coupler 500 and the second opto-coupler 600, and are used to receive the first regulation signal and the second regulation signal output by the first opto-coupler 500 and the second opto-coupler 600.

[0070] When the signal value of the first regulation signal is less than that of the second regulation signal, the power driving circuit 203 adjusts the brightness of the lamp 400 according to the first regulation signal output by the first dimming circuit 700;

[0071] When the signal value of the first regulation signal is greater than that of the second regulation signal, the power driving circuit 203 adjusts the brightness of the lamp 400 according to the second regulation signal output by the second dimming circuit 800.

[0072] Specifically, during the dimming process controlled by different signals of the adaptive dimming circuit 10, the power factor correction, the power driving circuit, the transformer isolation circuit 200, and the DC filtering circuit 300 are controlled by the regulation signal with the lower signal value among the regulation signals output by the first dimming circuit 700 or the second dimming circuit 800. Therefore, when the regulation signal output by the first dimming circuit 700 is less than the regulation signal output by the second dimming circuit 800, the power factor correction, the power driving circuit, and the transformer isolation circuit 200 select the regulation signal output by the first dimming circuit 700 to adjust the brightness of the lamp 400; and vice versa.

[0073] For example, the first dimming circuit 700 of the LED power supply is connected to a tangent controller (belonging to a leading-edge tangent or trailing-edge tangent dimmer), and controls the power driving circuit 203 through the first opto-coupler 500, so that the DC filtering circuit 300 changes following the first dimming circuit 700, and the voltage value or current value of the DC filtering circuit 300 is proportional to the first dimming circuit 700. When the first dimming circuit 700 changes from the maximum value to the minimum value, the DC filtering circuit 300 changes from the maximum value to the minimum value, and the brightness of the lamp 400 changes from 100% to 0% accordingly;

[0074] On the other hand, when the first dimming circuit 700 changes from the minimum value to the maximum value, the DC filtering circuit 300 changes from the minimum value to the maximum value, and the brightness of the lamp 400 changes from 0% to 100% accordingly; during this process, the second dimming circuit 800 maintains the maximum value, and the power factor correction, the power driving circuit, the transformer isolation circuit 200, the DC filtering circuit 300, and the lamp 400 are not controlled by the second dimming circuit 800.

[0075] The second dimming circuit 800 of the LED power supply is connected to a 0-10V controller (corresponding to 810). Through the second optocoupler 600 and the power driving circuit 203, the DC filtering circuit 300 changes following the second dimming circuit 800. The voltage value or current value of the DC filtering circuit 300 changes in a proportional relationship with the second dimming circuit 800. When the second dimming circuit 800 changes from the maximum value to the minimum value, the DC filtering circuit 300 changes from the maximum value to the minimum value, and the brightness of the lamp 400 changes from 100% to 0% accordingly.

[0076] On the other hand, when the second dimming circuit 800 changes from the minimum value to the maximum value, the DC filtering circuit 300 changes from the minimum value to the maximum value, and the brightness of the lamp 400 changes from 0% to 100% accordingly. During this process, the first dimming circuit 700 maintains the maximum value, and the power factor correction, power driving circuit, transformer isolation circuit 200, DC filtering circuit 300, and lamp 400 are not controlled by the first dimming circuit 700.

[0077] Using this technical solution, a dimming control circuit with two or more dimming signals for adaptive switching can eliminate the use of a single-chip microcomputer to process signals. Different signals are switched using hardware (opto-coupler), and the output voltage or output current of the LED power supply is controlled to achieve dimming. Since the entire process is controlled by analog signals, the smoothness of the dimming process is effectively improved, and no dimming frequency and dimming levels are generated during the dimming process. The dimming effect is quite excellent, and the cost is relatively low.

[0078] In some embodiments, to ensure the reliability of signal input, the first optocoupler 500 and the second optocoupler 600 connected in parallel can be connected in series with the input end of the power driving circuit 203.

[0079] Such as Figure 2 、 Figure 4 And Figure 5 As shown, one input end of the first optocoupler 500 (corresponding to U5A and U5B) is connected to the output end of the first dimming circuit 700 for receiving the first regulation signal (or the LED power supply tangent signal) output by the first dimming circuit 700. The output of the first optocoupler 500 (corresponding to U5A and U5B) is connected to the input end of the power driving circuit 203, and the first regulation signal (or the LED power supply tangent signal) is input into the power driving circuit 203.

[0080] One input terminal of the second opto-coupler 600 (corresponding to U4A and U4B) is connected to the output terminal of the second dimming circuit 800 for receiving the second regulation signal (or 0-10V signal) output by the second dimming circuit 800. The output of the second opto-coupler 600 (corresponding to U4A and U4B) is connected to the input terminal of the power drive circuit 203, and the second regulation signal (or 0-10V signal) is input into the power drive circuit 203.

[0081] The power drive circuit 203 then selects the one with the lower signal value as the regulation signal for regulating the brightness of the lamp 400 according to the input regulation signal.

[0082] In some embodiments, in order to improve the reliability and stability of signal output, a first controller U101 and a second field effect transistor VT203 may be provided in the power drive circuit 203. Among them, the first controller U101 has the functions of signal value comparison, selection and regulation.

[0083] The second field effect transistor VT203 has the function of a switch.

[0084] Specifically, the input terminal (corresponding to pin 2) of the first controller U101 is respectively connected to the output terminals of the first opto-coupler 500 and the second opto-coupler 600 through the tenth resistor R210 for receiving the regulation signals output by the first opto-coupler 500 and the second opto-coupler 600, and then comparing the signal values of the input regulation signals, and selecting the one with the smaller signal value as the regulation signal for regulating the brightness of the lamp 400.

[0085] Further, the gate of the second field effect transistor VT203 is connected to the output terminal (corresponding to pin 5) of the first controller U101 through the twenty-second resistor R222 and the fifth diode VD205 connected in parallel. The drain of the second field effect transistor VT203 is connected to one end of the transformer isolation circuit 202 (belonging to the power factor correction, power drive circuit and transformer isolation circuit 200). The source of the second field effect transistor VT203 is connected to the feedback terminal (corresponding to pin 3) of the first controller U101 through the seventeenth resistor R217.

[0086] When the first optocoupler 500 or the second optocoupler 600 inputs a regulation signal to the first controller U101, the pulse signal output from the output terminal (corresponding to pin 5) of the first controller U101 is input to the gate of the second field-effect transistor VT203 through the twenty-second resistor R222 and the fifth diode VD205, and a positive voltage is applied to the drain of the second field-effect transistor VT203. The second field-effect transistor VT203 is triggered to conduct. At this time, the regulation signal output by the first controller U101 passes through the transformer isolation circuit 202 (which belongs to the power factor correction, power drive circuit and transformer isolation circuit 200) and the DC filtering circuit 300 to regulate the brightness of the lamp 400.

[0087] In some embodiments, as Figure 4 shown, in order to improve the reliability and stability of signal output, a tangent signal input circuit 701 and a first control circuit 702 can be provided in the first dimming circuit 700. Among them, the tangent signal input circuit 701 is used to obtain the first regulation signal (or the LED power supply tangent signal) and perform voltage regulation on the first regulation signal (or the LED power supply tangent signal).

[0088] The first control circuit 702 is used to receive the processed first regulation signal (or the LED power supply tangent signal), and then output it to the signal input terminal of the first optocoupler 500.

[0089] Specifically, the signal input terminal of the tangent signal input circuit 701 is coupled to the output terminal of the dimming controller (the subsequent circuit corresponding to the ACI terminal) to receive the first regulation signal (or the LED power supply tangent signal) and perform voltage regulation processing on the first regulation signal (or the LED power supply tangent signal).

[0090] Further, the input terminal (corresponding to the TD-2.5V terminal) of the first control circuit 702 is connected to the output terminal (corresponding to the TD-2.5V terminal) of the tangent signal input circuit 701 through the fifty-fourth resistor R726 and the fifty-fifth resistor R727, and the output terminal of the first control circuit 702 is connected to the signal input terminal (corresponding to the U5A side) of the first optocoupler 500.

[0091] In some embodiments, in order to improve the reliability of the output regulation signal, a first amplifier U9C and a first output voltage sampling and voltage dividing circuit (formed by the fifty-sixth resistor R728, the fifty-seventh resistor R729, the fifty-ninth resistor R731, the sixtieth resistor R732 and the sampling resistor VR2) can be provided in the first control circuit 702. Among them, the first output voltage sampling and voltage dividing circuit is used to obtain the voltage or current signal at the output terminal (corresponding to V+ and V-) of the DC filtering circuit 300, and after processing it, obtain a reference voltage (corresponding to TD).

[0092] Specifically, the non-inverting input terminal of the first amplifier U9C (corresponding to pin 8) is connected to the output terminal of the tangent signal input circuit 701 (corresponding to the TD-2.5V terminal) through the fifty-fourth resistor and the fifty-fifth resistor R727, for receiving the first control signal (or the LED power tangent signal).

[0093] The inverting input terminal of the first amplifier U9C (corresponding to pin 9) is connected to the output terminal of the first output voltage sampling and voltage dividing circuit (corresponding to the TDIN terminal), for receiving the voltage signal (or the reference voltage). The output terminal of the first amplifier U9C (corresponding to pin 10) is connected to the signal input terminal of the first optocoupler 500 (corresponding to one end of U5B) through the ninth diode VD702.

[0094] It should be noted that the cathode of the ninth diode VD702 is connected to the output terminal of the first amplifier U9C (corresponding to pin 10), and the anode of the ninth diode VD702 is connected to the signal input terminal of the first optocoupler 500 (corresponding to one end of U5B).

[0095] Specifically, when power is supplied to the L / N terminal, after passing through the AC-DC filtering circuit 100, the power factor correction circuit 201 starts to work, obtaining a DC voltage of about 430V, and the factor at this time is greater than 0.9.

[0096] The power drive circuit 203 is powered on and starts to work, and delivers electrical energy to the secondary DC filtering circuit 300 through the transformer T2C of the transformer isolation circuit 202. After passing through the DC filtering circuit 300, it is output to the lamp 400 to light up the lamp 400. Since no tangent controller (belonging to the leading-edge tangent or trailing-edge tangent dimmer) and 0-10V controller are connected, the circuit output is the set maximum value, and the lamp brightness is 100%.

[0097] Tangent dimming principle: When a tangent controller (belonging to the leading-edge tangent or trailing-edge tangent dimmer) is connected to the L / N terminal, the tangent signal input circuit 701 and the first control circuit 702 start to be controlled.

[0098] Among them, the tangent current maintaining circuit composed of the twenty-ninth resistor R701, the thirtieth resistor R702, the thirty-first resistor R703, the thirty-second resistor R704, the thirty-third resistor R705, the thirty-fourth resistor R706, the forty-ninth resistor R721, the fiftieth resistor R722, the fifty-first resistor R723, the fifty-second resistor R724, the fifty-third resistor R725, the fifty-fourth resistor R726, the nineteenth capacitor C701, the twenty-second capacitor C704, the eighth diode VD701, the third field effect transistor VT701, the second triode VT702, the fifth triode VT705 and the sixth triode VT706 provides a maintaining current for the tangent controller (belonging to the dimming controller MCU), so that the tangent controller (belonging to the front-edge tangent or trailing-edge tangent dimmer) can be tangent normally during 0-100% dimming;

[0099] The tangent input circuit is composed of the forty-fourth resistor R716, the forty-fifth resistor R717, the forty-third resistor R715, the forty-second resistor R714, the forty-sixth resistor R718, the forty-eighth resistor R720, the thirty-eighth resistor R710, the forty-first resistor R713, the forty-seventh resistor R719, the thirty-fifth resistor R707, the thirty-seventh resistor R709, the twentieth capacitor C702, the twenty-first capacitor C703, the fourth triode VT704 and the fourth optocoupler U8A. When the tangent controller (belonging to the front-edge tangent or trailing-edge tangent dimmer) is tangent at 0-100%, the AC waveform after tangency at the AC end is attenuated by the thirty-fifth resistor R707, the thirty-sixth resistor R708 and the thirty-seventh resistor R709 and then the pulsed signal inverted by the third triode VT703 is input to the input end of the fourth optocoupler U8A, transmitted to the output end through the fourth optocoupler U8A, and inverted again by the forty-second resistor R714, the forty-first resistor R713, R712 and the fourth triode VT704, so that the phase of the collector of the fourth triode VT704 is consistent with the phase of the fourth optocoupler U8A;

[0100] Among them, the forty-fourth resistor R716, the forty-fifth resistor R717, the forty-third resistor R715, the forty-sixth resistor R718, the forty-eighth resistor R720, the forty-seventh resistor R719, the twentieth capacitor C702 and the twenty-first capacitor C703 form a low-pass filtering voltage dividing circuit. The pulsed signal at the collector of the fourth triode VT704 is filtered by the forty-third resistor R715, the forty-sixth resistor R718, the twentieth capacitor C702 and the twenty-first capacitor C703, and a DC voltage of 0-2.5V is obtained at TD-2.5V.

[0101] Among them, the twenty-ninth resistor R701 and the forty-eighth resistor R720 are pull-down resistors for adjusting the maximum voltage, and the forty-fourth resistor R716 and the forty-fifth resistor R717 are pull-up resistors for adjusting the minimum voltage; at this time, the pulse voltage between 0 - 2.5V is proportional to the base voltage of the third triode VT703. When the tangent controller (belonging to the dimming controller MCU) tangents from 0 - 100%, the voltage at TD - 2.5V also changes from 0 - 2.5V accordingly;

[0102] The sixty-first resistor R733, the sixty-second resistor R734, the fifty-fifth resistor R727, the fifty-sixth resistor R728, the ninth diode VD702, the twenty-third capacitor C705, the first optocoupler (corresponding to U5A and U5B), and the first amplifier U9C form an error amplification feedback loop.

[0103] The fifty-seventh resistor R729, the fifty-eighth resistor R730, the fifty-ninth resistor R731, and the sixtieth resistor R732 form an output voltage sampling voltage division circuit, VR2 is a current sampling circuit, and the output voltage or current control can be switched. The sixty-first resistor R733 and the sixty-second resistor R734 supply power to the first optocoupler (corresponding to U5A and U5B). The non-inverting input terminal (corresponding to pin 8) of the first amplifier U9C is connected to the TD - 2.5V terminal through the fifty-fifth resistor R727, and the inverting input terminal (corresponding to pin 9) of the first amplifier U9C is connected to the TDIN terminal;

[0104] When the voltage at the TD - 2.5V terminal changes from 0 - 2.5V, through the control of the error amplification feedback loop, the output voltage also changes proportionally, causing the brightness of the lamp to change from 0 - 100% to achieve dimming;

[0105] Conversely, when the tangent controller (belonging to the leading-edge tangent or trailing-edge tangent dimmer) tangents from 100 - 0%, the brightness of the lamp 400 also changes from 100 - 0% to achieve cyclic dimming; during this process, the second dimming circuit 800 does not participate in the work and is not affected by the second dimming circuit 800.

[0106] In some embodiments, as Figure 5 shown, in order to improve the reliability and stability of signal output, the second dimming circuit 800 may include a 0 - 10V signal input circuit 801 and a second control circuit 802. Among them, the 0 - 10V signal input circuit 801 is used to obtain the second regulation signal (or 0 - 10V signal) and adjust the voltage of the second regulation signal (or 0 - 10V signal).

[0107] The second control circuit 802 is used to receive the processed second regulation signal (or 0 - 10V signal) and then output it to the second optocoupler 600.

[0108] Specifically, the signal input terminal of the 0-10V signal input circuit 801 (corresponding to the connection terminal of the sixty-sixth resistor R805 and the sixty-seventh resistor R806) is coupled to the output terminal of the 0-10V controller (belonging to the dimming controller MCU) (corresponding to D+), which is used to receive the second regulation signal (or 0-10V signal) and perform voltage regulation processing on the second regulation signal (or 0-10V signal).

[0109] Further, the input terminal of the second control circuit 802 (corresponding to the 0-10V 2.5V terminal) is connected to the output terminal of the 0-10V signal input circuit (corresponding to the 0-10V - 2.5V terminal) through the seventy-eighth resistor R816, and is used to receive the second regulation signal (or 0-10V signal). The output terminal of the second control circuit 802 is coupled to the signal input terminal of the second optocoupler 600 (corresponding to the U4A side).

[0110] In some embodiments, in order to improve the reliability of the output regulation signal, a second amplifier U9D and a second output voltage sampling and voltage dividing circuit (formed by connecting the seventy-second resistor R811 - the fifty-ninth resistor R814 and the sampling resistor VR1) may be provided in the second control circuit 802. Among them, the second output voltage sampling and voltage dividing circuit is used to obtain the voltage or current signal at the output terminal of the DC filtering circuit 300 (corresponding to V+ and V-), and after processing it, a reference voltage (corresponding to 10VIN) is obtained.

[0111] The non-inverting input terminal of the second amplifier U9D (corresponding to pin 12) is connected to the output terminal of the 0-10V signal input circuit 801 (corresponding to the 0-10V 2.5V terminal) through the resistor R815, and is used to receive the second regulation signal;

[0112] The inverting input terminal of the second amplifier U9D (corresponding to pin 13) is connected to the output terminal of the second output voltage sampling and voltage dividing circuit (corresponding to the 10VIN terminal), and is used to receive the voltage signal (or reference voltage) output by the second output voltage sampling and voltage dividing circuit. The output terminal of the second amplifier U9D (corresponding to pin 14) is connected to the signal input terminal of the second optocoupler 600 (corresponding to the U4B side) through the diode VD801.

[0113] It should be noted that the cathode of the diode VD801 is connected to the output terminal of the second amplifier U9D (corresponding to pin 14), and the anode of the diode VD801 is connected to the signal input terminal of the second optocoupler 600 (one end of the U4B).

[0114] Specifically, the 0-10V dimming principle: When a 0-10V controller 810 is connected to the D + / D- terminals, the second dimming circuit 800 starts to be controlled.

[0115] Among them, the sixty-fourth resistor R802, the sixty-fifth resistor R803, the sixty-sixth resistor R805, the sixty-sixth resistor R804, the fourth amplifier U9A, and the third zener diode VS801 form a 10V power supply circuit to provide 10V voltage to the D+ terminal, which is compatible with active or passive 10V voltage controllers.

[0116] The sixty-seventh resistor R806, the sixty-eighth resistor R807, the sixty-ninth resistor R808, the seventieth resistor R809, the seventy-first resistor R810, the seventy-second resistor R811, and the twenty-fifth capacitor C802 form a voltage dividing and filtering circuit.

[0117] When the voltage at the D+ terminal is 10V, the voltage at the 0 - 10V - 2.5V terminal is 2.5V.

[0118] The seventy-first resistor R810 and the seventy-second resistor R811 are pull-down resistors that can adjust the maximum value of the 0 - 10V - 2.5V terminal; the sixty-ninth resistor R808 and the seventieth resistor R809 are pull-up resistors that can adjust the minimum value.

[0119] The seventy-eighth resistor R816, the seventy-ninth resistor R816, the eightieth resistor R818, the eighty-first resistor R819, the twenty-sixth capacitor C803, the twenty-seventh capacitor C804, the twelfth diode VD801, the second optocoupler (corresponding to U4B), and the second amplifier U9D form an error amplification feedback loop.

[0120] Among them, the seventy-fourth resistor R812, the seventy-fifth resistor R813, the seventy-sixth resistor R814, and the seventy-seventh resistor R815 are an output voltage sampling and voltage dividing circuit, VR1 is a current sampling circuit, and the output voltage or current control can be switched. The eightieth resistor R818 and the eighty-first resistor R819 supply power to the second optocoupler (corresponding to U4B). The non-inverting input terminal (corresponding to pin 12) of the second amplifier U9D is connected to the 0 - 10V - 2.5V terminal through the seventy-eighth resistor R816, and the inverting input terminal (corresponding to pin 13) of U9D is connected to the 10VIN terminal;

[0121] When the 0 - 10V controller adjusts from 0 - 10V, the voltage at the 0 - 10V - 2.5V terminal changes from 0 - 2.5V accordingly. Through the control of the error amplification feedback loop, the output voltage also changes proportionally, making the brightness of the lamp 400 change from 0 - 100%, realizing dimming; conversely, when the 0 - 10V controller adjusts from 10 - 0V, the brightness of the lamp 400 also changes from 100 - 0%, realizing cyclic dimming. In this process, the first dimming circuit 700 does not participate in the work and is not affected by the first dimming circuit 700.

[0122] In some embodiments, such as Figure 2As shown, in order to improve the stability of the operation of the lamp 400, a transformer isolation circuit 202 can be provided on the output side of the power drive circuit 203, which has the functions of voltage transformation and voltage isolation.

[0123] Specifically, the input end of the transformer isolation circuit 202 is connected to the output end of the AC-DC filtering circuit 100 for obtaining a voltage signal. One end of the transformer isolation circuit 202 is connected to the output end of the power drive circuit 203, forming a current loop on the primary side of the transformer isolation circuit 202.

[0124] The output end of the transformer isolation circuit 202 is coupled to the input end of the DC filtering circuit 300, and the current signal is coupled to the DC filtering circuit 300 side.

[0125] Specifically, the transformer isolation circuit 202 is provided with a transformer T2C. Among them, one end (corresponding to pin 1) of the primary winding of the transformer T2C is connected to the output end of the AC-DC filtering circuit 100 for obtaining a voltage signal, and the other end (corresponding to pin 3) of the primary winding of the transformer T2C is connected to the output end of the power drive circuit 203, forming a current loop on the primary side of the transformer T2C.

[0126] The magnetic windings (corresponding to pins 9 and 10) of the transformer T2C are respectively connected to the input end of the DC filtering circuit 300, and the voltage / current after voltage transformation is output to one side of the DC filtering circuit 300.

[0127] In some embodiments, as Figure 6 shown, in order to improve the safety of the operation of the lamp 400, a constant voltage / constant current circuit 900 can be provided in the circuit, which is used to control the stability of the output current or voltage of the dimming circuit, and avoid the lamp 400 being affected by voltage fluctuations and affecting its operation reliability.

[0128] Specifically, one input end of the constant voltage / constant current circuit 900 is connected to the output end (corresponding to V+ and V- terminals) of the DC filtering circuit 300 for obtaining the voltage / current signal output by the DC filtering circuit 300.

[0129] The other input end of the constant voltage / constant current circuit 900 is connected to the 2.5V power supply terminal, and the output end (corresponding to the U6B side) of the constant voltage / constant current circuit 900 is coupled to the input end (corresponding to the U6A side) of the power drive circuit 203.

[0130] Further, the constant voltage / constant current circuit 900 includes a third amplifier U9B and a third optocoupler (corresponding to U6A and U6B). Among them, the non-inverting input terminal (corresponding to pin 5) of the third amplifier U9B is connected to the 2.5V power supply terminal, and the inverting input terminal (corresponding to pin 6) of the third amplifier U9B is connected to the output terminal of the DC filtering circuit 300 (corresponding to V+ and V- terminals). One end (corresponding to pin 2) of the third optocoupler (corresponding to U6A and U6B) is connected to the output terminal (corresponding to pin 7) of the third amplifier U9B through a diode VD901, and the output terminal of the third optocoupler (corresponding to the U6B side) is connected to the input terminal of the power drive circuit 203 (corresponding to the U6A side).

[0131] That is, the constant voltage / constant current circuit 900 processes the voltage / current signal output by the DC filtering circuit 300 and then inputs it into the first controller U101 through the third optocoupler (corresponding to U6A and U6B). The first controller U101 adjusts the output current / voltage according to the feedback voltage / current signal.

[0132] In some embodiments, in order to improve the reliability of the power supply, a power factor correction circuit 201 may be provided in the adaptive dimming circuit. Among them, the power factor correction circuit 201 is used to detect the output side of the AC / DC filtering circuit 100.

[0133] When the mains power is connected to the L / N terminal, after being processed by the AC / DC filtering circuit 100, the power factor correction circuit 201 starts to work, obtains a DC voltage of about 430V, and after being analyzed and processed by the second controller U201 in the power factor correction circuit 201, the power factor during the operation of the circuit is obtained, and the power factor is greater than 0.9.

[0134] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the spirit and scope protected by the present invention and the claims. All of these are within the protection scope of the present invention.

Claims

1. An adaptive dimming circuit, characterized in that, Comprising: A power drive circuit, which is configured in the dimming circuit and is used to output a drive signal; A DC filtering circuit, whose input end is coupled to the output end of the power drive circuit, is used to receive the drive signal input by the power drive circuit, and the drive signal is used to control the working state of the lamp; A first dimming circuit, one signal input end of which is connected to the output end of the dimming controller, is used to receive a first regulation signal and process the input first regulation signal; A first opto-coupler, whose input end is coupled to the output end of the first dimming circuit, is used to receive the first regulation signal processed by the first dimming circuit; A second dimming circuit, one signal input end of which is connected to the output end of the dimming controller, is used to receive a second regulation signal and process the input second regulation signal; A second opto-coupler, whose input end is coupled to the output end of the second dimming circuit, is used to receive the second regulation signal processed by the second dimming circuit; wherein, The signal input end of the power drive circuit is respectively connected to the output ends of the first opto-coupler and the second opto-coupler, and is used to receive the first regulation signal and the second regulation signal; When the signal value of the processed first regulation signal is less than the signal value of the processed second regulation signal, the power drive circuit adjusts the brightness of the lamp according to the first regulation signal output by the first dimming circuit; When the signal value of the processed first regulation signal is greater than the signal value of the processed second regulation signal, the power drive circuit adjusts the brightness of the lamp according to the second regulation signal output by the second dimming circuit; The first dimming circuit includes a tangent signal input circuit and a first control circuit. The signal input end of the tangent signal input circuit is coupled to the output end of the dimming controller and is used to receive the first regulation signal. The input end of the first control circuit is connected to the output end of the tangent signal input circuit, and the output end of the first control circuit is coupled to the signal input end of the first opto-coupler; The first control circuit includes a first amplifier and a first output voltage sampling and voltage dividing circuit. The non-inverting input end of the first amplifier is connected to the output end of the tangent signal input circuit and is used to receive the first regulation signal. The inverting input end of the first amplifier is connected to the output end of the first output voltage sampling and voltage dividing circuit and is used to receive a voltage signal. The output end of the first amplifier is connected to the signal input end of the first opto-coupler; The second dimming circuit includes a 0-10V signal input circuit and a second control circuit. The signal input end of the 0-10V signal input circuit is coupled to the output end of the dimming controller and is used to receive the second regulation signal. The input end of the second control circuit is connected to the output end of the 0-10V signal input circuit, and the output end of the second control circuit is coupled to the signal input end of the second opto-coupler; The second control circuit includes a second amplifier and a second output voltage sampling and voltage-dividing circuit. The non-inverting input terminal of the second amplifier is connected to the output terminal of the 0-10V signal input circuit for receiving the second regulation signal. The inverting input terminal of the second amplifier is connected to the output terminal of the second output voltage sampling and voltage-dividing circuit for receiving a voltage signal. The output terminal of the second amplifier is connected to the signal input terminal of the second optocoupler.

2. The adaptive dimming circuit according to claim 1, wherein The first optocoupler and the second optocoupler connected in parallel are connected in series with the input terminal of the power driving circuit.

3. The adaptive dimming circuit according to claim 2, wherein The power driving circuit includes a first controller. The input terminals of the first controller are respectively connected to the output terminals of the first optocoupler and the second optocoupler.

4. The adaptive dimming circuit according to claim 1, wherein It further includes a transformer isolation circuit. One end of the transformer isolation circuit is connected to the output terminal of the power driving circuit, The output terminal of the transformer isolation circuit is coupled to the input terminal of the DC filtering circuit.

5. The adaptive dimming circuit according to claim 4, wherein It further includes a constant voltage / constant current circuit. One input terminal of the constant voltage / constant current circuit is connected to the output terminal of the DC filtering circuit, The other input terminal of the constant voltage / constant current circuit is connected to the 2.5V power supply terminal, The output terminal of the constant voltage / constant current circuit is coupled to the input terminal of the power driving circuit.

6. The adaptive dimming circuit according to claim 5, wherein The constant voltage / constant current circuit includes a third amplifier and a third optocoupler, The non-inverting input terminal of the third amplifier is connected to the 2.5V power supply terminal, The inverting input terminal of the third amplifier is connected to the output terminal of the DC filtering circuit, One end of the third optocoupler is coupled to the output terminal of the third amplifier, The output terminal of the third optocoupler is coupled to the input terminal of the power driving circuit.

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