All-in-one dimming circuit meeting Class2

Abstract

The utility model discloses an all-in-one light modulation circuit satisfying Class2, comprising a power supply input end, a plurality of mutually independent output channels and an all-in-one light modulation module, the all-in-one light modulation module comprises at least one of a silicon controlled rectifier light modulation module, a PWM light modulation module, a DALI light modulation module and a 0-10V light modulation module, each output channel comprises a sampling circuit, an amplifying circuit, a comparison circuit, a signal control circuit, a switching circuit and a power supply output end, the output end of the all-in-one dimming module is electrically connected with the switching circuit to carry out dimming control, the output power of each output channel is less than or equal to 100W, and the current of each output channel is less than or equal to 5A.

Description

TECHNICAL FIELD

[0001] The utility model relates to LED drive power supply technical field, especially a multi-in-one light adjusting circuit satisfying Class2. BACKGROUND

[0002] The power supply for LED lighting can be the power supply evaluated by UL1310 (Class2 power unit), UL60950-1 (Power Supply), UL1012 (non Class 2 power unit) and the like standards, wherein the CLASS2 considers the current and energy. If confirmed as the CLASS2 circuit, some accessory requirements used in connection with the circuit can be reduced, such as reducing the fireproof shell in the lamp, the insulation of LED wiring and the like, so as to reduce the lamp design requirements and the lamp design cost. For the LED drive power supply defined as the Class2 output authentication, the following basic electrical properties need to be satisfied: the output voltage satisfies UL8750, and the output current and the power under the normal or abnormal conditions need to satisfy UL1310. The power energy of the output of the existing high-power LED drive power supply is greater than 100W, and the current is greater than 5A, so that there is a safety hidden danger in application. In order to improve the safety reliability, a plurality of power supplies less than 100W can be selected to be applied, or a power supply with multiple outputs and satisfying Class2 is selected to be applied. Then the number of power supplies used in the former increases, the wiring becomes complex, and the cost also increases by the same proportion. The cost of the power supply in the latter is very expensive and not universal, which is equivalent to professional customization, and cannot satisfy the application requirements of the LED. CONTENT OF THE UTILITY MODEL

[0003] The utility model aims at at least solving one of the technical problems in the prior art, and provides a multi-in-one light adjusting circuit which can change a conventional power supply not satisfying Class2 into a low-cost power supply satisfying Class2.

[0004] The multi-in-one dimming circuit satisfying Class 2 according to the embodiment of the utility model, including power input end, multiple independent output channels and multi-in-one dimming module, the multi-in-one dim light module includes at least one of silicon controlled dimming module, PWM dimming module, DALI dimming module and 0-10V dimming module, the output channel includes sampling circuit, amplification circuit, comparison circuit, signal control circuit, switch circuit and power output end, the output end of the multi-in-one dimming module is electrically connected with the switch circuit to carry out dimming control, and the output power of each output channel is less than or equal to 100W, and the current is less than or equal to 5A;The power output end is electrically connected with the power input end and the switch circuit respectively, the input end of the sampling circuit is electrically connected with the power output end to sample the current signal of load, the output end of the sampling circuit is electrically connected with the input end of the amplification circuit to amplify the current signal obtained by sampling to obtain an amplified signal, the amplification circuit is electrically connected with the comparison circuit to compare the amplified signal with a reference signal to obtain a comparison signal, and the signal control circuit is electrically connected with the comparison circuit to control the on-off state of the switch circuit according to the comparison signal to realize overload and short-circuit protection.

[0005] The multi-in-one dimming circuit satisfying Class 2 according to the embodiment of the utility model has at least the following beneficial effects: the utility model divides a conventional power supply with large power into multiple independent output channels (each channel output power is less than or equal to 100W, and the current is less than or equal to 5A) satisfying Class 2, the output power of each output channel can be independently set by changing the parameters of the sampling module, and the output channels do not interfere with each other, a conventional power supply not satisfying Class 2 is changed into a multi-output power supply satisfying Class 2, multiple dimming modes are compatible, and application is facilitated.

[0006] Additional aspects and advantages of the utility model will be partially given in the following description, partially become obvious from the following description, or be understood by the practice of the utility model. BRIEF DESCRIPTION OF DRAWINGS

[0007] The specific embodiments of the present application will be further described below with reference to the accompanying drawings.

[0008] Figure 1 is the principle block diagram of the multi-in-one dimming circuit satisfying Class 2;

[0009] Figure 2 is the circuit principle diagram of the multi-in-one dimming circuit satisfying Class 2;

[0010] Figure 3 is the circuit principle diagram of the silicon controlled dimming module. DETAILED DESCRIPTION

[0011] This part will describe the specific embodiments of the present application in detail, the preferred embodiments of the present application are shown in the drawings, the role of the drawings is to supplement the description of the text part with graphics, so that people can intuitively and visually understand each technical feature and the overall technical scheme of the present application, but it cannot be understood as the limitation of the protection scope of the present application.

[0012] In the description of the present application, it is understood that the orientation description, such as the orientation or position relationship of the upper, lower, front, rear, left, right and the like indicated by the drawings, is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, therefore it cannot be understood as the limitation of the present application.

[0013] In the description of the present application, the meaning of several is one or more, the meaning of multiple is two or more, greater than, less than, more than and the like are understood as not including the number, above, below, within and the like are understood as including the number. If it is described to the first, second, it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.

[0014] Reference Figures 1 to 2This utility model discloses a Class 2 all-in-one dimming circuit, comprising a power input terminal, a power supply circuit 20, and multiple independent output channels 10. Each output channel 10 includes a sampling circuit 11, an amplification circuit 12, a comparator circuit 13, a signal control circuit 15, a switching circuit 16, and a power output terminal. The power supply circuit 20 is electrically connected to the power input terminal to convert the input voltage into an operating voltage to power the sampling circuit 11, the amplification circuit 12, the comparator circuit 13, the signal control circuit 15, and the switching circuit 16, respectively. The output power of each output channel 10 is ≤100W. The current is ≤5A; the power output terminal is electrically connected to the power input terminal and the switching circuit 16 respectively; the input terminal of the sampling circuit 11 is electrically connected to the power output terminal to sample the current signal of the load; the output terminal of the sampling circuit 11 is electrically connected to the input terminal of the amplifier circuit 12 to amplify the sampled current signal to obtain an amplified signal; the amplifier circuit 12 is electrically connected to the comparator circuit 13 to compare the amplified signal with the reference signal to obtain a comparison signal; the signal control circuit 15 is electrically connected to the comparator circuit 13 to control the on / off state of the switching circuit 16 according to the comparison signal to achieve overload and short circuit protection.

[0015] This invention divides a high-power conventional power supply into multiple independent output channels that meet Class 2 requirements (each channel has an output power ≤100W and a current ≤5A). The output power of each channel can be independently set by changing the parameters of the sampling module, without interference. This transforms a conventional power supply that does not meet Class 2 requirements into a multi-output power supply that meets Class 2 requirements, while also being compatible with various dimming methods for ease of application. For example, a 300W 24V power supply can be converted into four independent output channels: one 100W channel, one 30W channel, one 80W channel, and one 90W channel. Each output channel operates independently. If one of the 30W channels experiences an overload, it will perform overload protection based on a comparison signal, while the other three channels continue to operate normally. This is equivalent to obtaining four or even more independent Class 2 power supplies with overload or short-circuit protection, making LED applications much more convenient. Even if this 300W conventional power supply does not have overload or short circuit protection, this circuit transformation can provide independent protection for each output channel. This is equivalent to the 300W conventional power supply also having overload protection, improving the safety of the application, making it more convenient and cost-effective in LED driver applications.

[0016] like Figure 2 As shown, in a specific application, it includes four output channels 10. Each output channel 10 has a positive output terminal and a negative output terminal, and a positive input terminal and a negative input terminal. The power input terminal can be constant voltage or constant current. The positive input terminal is electrically connected to the four positive output terminals respectively, and the four negative input terminals are grounded. The power supply circuit 20 can be a DC-DC topology, such as...Figure 2 The linear LDO output operating voltage VCC is used to power each circuit, and the circuit structures of the four output channels 10 are the same, but the specific parameters in the circuits are different according to the respective power. Take the specific circuit of one of the output channels 10 as an example: the switching circuit 16 includes a MOS tube Q1, a resistor R1, and a resistor R2, the D pole of the MOS tube Q1 is electrically connected with the negative output end, the G pole of the MOS tube Q1 is electrically connected with one end of the resistor R2, the other end of the resistor R2 is electrically connected with one end of the resistor R1 and the signal control circuit 15 respectively, the other end of the resistor R1 is electrically connected with the power supply circuit 20 to input the operating voltage VCC, and the S pole of the MOS tube Q1 is electrically connected with the sampling circuit 11. The sampling circuit 11 includes a resistor R6, one end of the resistor R6 is electrically connected with the S pole of the MOS tube Q1 and the input end of the amplifying circuit 12 respectively, and the other end of the resistor R6 is grounded. The amplifying circuit 12 includes an operational amplifier U1, a resistor R8, a resistor R10, and a capacitor C4, the positive input end of the operational amplifier U1 is electrically connected with the R6 of the sampling circuit 11, the negative input end of the operational amplifier U1 is electrically connected with one end of the resistor R8, one end of the resistor R10, and one end of the capacitor C4 respectively, the other end of the resistor R8 and the other end of the capacitor C4 are electrically connected with the output end of the operational amplifier U1 respectively, the output end of the operational amplifier U1 is electrically connected with the comparing circuit 13, and the other end of the resistor R10 is grounded. The comparing circuit 13 includes a comparator U2, a resistor R5, a capacitor C1, and a reference circuit 13, the output end of the amplifying circuit 12 is electrically connected with the positive input end of the comparator U2 and one end of the capacitor C1 through the series connection of the resistor R5 respectively, the other end of the capacitor C1 is electrically connected with the output end of the comparator U2, the reference circuit 13 is electrically connected with the negative input end of the comparator U2, and the output end of the comparator U2 is electrically connected with the delay circuit 14.

[0017] The reference circuit 13 includes a resistor R9, a resistor R11, and a capacitor C5, one end of the resistor R9 is electrically connected with the power supply circuit 20 to input the operating voltage VCC, the other end of the resistor R9 is electrically connected with one end of the resistor R11, one end of the capacitor C5, and the negative input end of the comparator U2 respectively, the other end of the resistor R11 and the other end of the capacitor C5 are grounded respectively. The signal control circuit 15 includes a MOS tube Q2 and the delay circuit 14, the delay circuit 14 includes a diode D1, a resistor R7, and a capacitor C3, the anode of the diode D1 is electrically connected with the output end of the comparing circuit 13, the cathode of the diode D1 is electrically connected with one end of the resistor R7, one end of the capacitor C3, and the G pole of the MOS tube Q2 respectively, the other end of the resistor R7, the other end of the capacitor C3, and the S pole of the MOS tube Q2 are grounded respectively, and the D pole of the MOS tube Q2 is electrically connected with the switching circuit 16.

[0018] When the power output terminal works normally, the power-on makes the MOS tube Q1 conduct, and a voltage is generated on the resistor R6, which is the sampling signal (load current signal). The greater the value of the resistor R6, the smaller the corresponding load current and output power. That is, the output power of the output channel 10 can be adjusted by adjusting the size of the resistor R6, so that the output power is not greater than 100W and the output current is not greater than 5A, so as to meet the Class 2. The sampling signal is sent to the operational amplifier U1 through the resistor R4 for signal amplification, and the amplification factor is determined by the parameters of the operational amplifier U1, the resistor R8, the resistor R10 and the capacitor C4. The amplified signal is sent to the voltage comparator U2 through the resistor R5, and the reference of U2 is determined by the resistor R9, the resistor R11 and the capacitor C5 in the reference circuit 13. When working normally, the amplified signal is smaller than the reference voltage of U2, and the 7th pin of U2 outputs low level. At this time, the MOS tube Q2 is cut off, and the working voltage VCC drives the MOS tube Q1 to normally conduct through the resistor R1 and the resistor R2, and the load works normally.

[0019] When the power output terminal is overloaded, the sampling signal generated on the resistor R6 is sent to the operational amplifier U1 through the resistor R4, and then to the voltage comparator U2 through the resistor R5. At this time, the amplified signal is greater than the reference voltage, and the 7th pin of U2 outputs high level. At this time, the high level charges the capacitor C3 through the diode D1. When the voltage of the capacitor C3 reaches the turn-on voltage of the MOS tube Q2, the MOS tube Q2 is turned on, which pulls down the driving voltage of the MOS tube Q1, so that the MOS tube Q1 is cut off, and the output is turned off, protecting the LED. After the MOS tube Q1 is cut off, the sampling signal generated on the resistor R6 is zero, and after amplification, the voltage comparator U2 still outputs low level, and the diode D1 is in reverse cut-off. The capacitor C3 and the resistor R7 form a discharge circuit, and the discharge time is determined by the parameters of the capacitor C3 and the resistor R7. When the voltage of the capacitor C3 drops to the cut-off voltage of the MOS tube Q2, the MOS tube Q2 is cut off, and the MOS tube Q1 is turned on again, and the LED is lit again. Similarly, if overloaded again, the above steps will be repeated, and the opening and closing time interval of the LED will be determined by the capacitor C3 and the resistor R7. The flashing of the LED will prompt that the overload state needs to be checked and eliminated. The LED is in the process of closing-lighting-overload-closing, effectively protecting the overheating and overheating damage of the LED caused by overload. If the power output terminal is in a short circuit state, Q1 will be turned off again in an instant after Q1 is turned on, and will be in intermittent trial conduction all the time. The LED does not light (the conduction time is too short, and the brightness cannot be observed by the naked eye) until the short circuit is restored, and the LED restores the light. At the same time of the above process, other channels can also be overloaded or short-circuited at the same time, and the phenomenon is the same as above. When the fault is eliminated and restored to normal, each channel is independent and complementary to each other.

[0020] The utility model discloses reduce the threshold of CLASS2 application, and the ordinary power supply and CLASS2 principle are combined, and the application that satisfies CLASS2 is realized, and the overload application of LED is effectively protected, the service life of LED is promoted, the risk of drive due to overload overheating is reduced, the application versatility of drive is promoted, and production replacement is more convenient.

[0021] As Figure 3In some embodiments, the controllable silicon dimming module includes a controllable silicon dimmer, a controllable silicon freewheeling module 31, a controllable silicon sampling module 32, an isolation module 33 and a dimming control module 34. In practical applications, the power input end can be connected to the live wire and the zero line. The controllable silicon dimmer is electrically connected to the input end of the controllable silicon freewheeling module 31. The output end of the controllable silicon freewheeling module 31 is electrically connected to the input end of the controllable silicon sampling module 32. The output end of the controllable silicon sampling module 32 is electrically connected to one end of the isolation module 33. The other end of the isolation module 33 is electrically connected to the input end of the dimming control module 34. The output end of the dimming control module 34 is electrically connected to the switching circuit to output the PWM signal. The dimming signal of the controllable silicon dimmer is transmitted to the controllable silicon sampling module 32 through the controllable silicon freewheeling module 31. The controllable silicon sampling module 32 can convert the dimming signal into a square wave signal to control the dimming control module to output the PWM signal. The controllable silicon freewheeling module 31 includes a diode D2, a constant current IC U3, a resistor R50 and a MOS tube Q3. The anode of the diode D2 is electrically connected to the controllable silicon dimmer. The cathode of the diode D2 is electrically connected to one end of the constant current IC U3. The other end of the constant current IC U3 is electrically connected to the drain of the MOS tube Q3 through the series connection of the voltage dividing resistor R50. The source of the MOS tube Q3 is grounded. The gate of the MOS tube Q3 is electrically connected to the controllable silicon sampling module 32. The controllable silicon sampling module 32 includes a MOS tube Q4, a resistor R100 and a resistor R30. One end of the resistor R100 and the gate of the MOS tube Q4 are electrically connected. The other end of the resistor R100 is electrically connected to the cathode of the diode D2. The source of the MOS tube Q4 is grounded. One end of the resistor R30 is connected to the VCC voltage. The drain of the MOS tube Q4 is electrically connected to the other end of the resistor R30 and the isolation module 33, respectively. The isolation module 33 uses an optical coupler U4. The dimming control module 34 includes an integration circuit and a main control chip U5. The integration circuit includes a MOS tube Q5, a resistor R20, a resistor R40 and a capacitor C10. One output end of the isolation circuit is electrically connected to the drain of the MOS tube Q3 and one end of the resistor R20 through the series connection of the resistor R40, respectively. The other end of the resistor R20 is electrically connected to one end of the capacitor C10 and the input end of the main control chip U5, respectively. The other end of the capacitor C10 and the source of the MOS tube Q5 are grounded, respectively. The other output end of the isolation module 33 is electrically connected to the gate of the MOS tube Q5 through the series connection of the resistor.Wherein U3 is a linear constant current IC, the constant current is slightly greater than the thyristor freewheeling value, generally greater than 20mA, the current is determined by the constant current IC U3, ZD1 is a voltage stabilizing tube for protecting the MOS drive electrode, generally a 12V voltage stabilizing tube is used, the resistance R100 provides a bias voltage for the MOS tube conduction, when the thyristor dimmer is turned on, the MOS tube Q3 is turned on, the MOS tube Q4 is also turned on, at this time the optocoupler U4 is cut off, the optocoupler U4 emitter output high level passes through the resistance R90 to control the MOS tube Q5 to be turned on, and the low level output through the resistance R20, when the thyristor dimmer is not turned on, the VIN node connected with one end of the resistance R100 has no voltage, the MOS tube Q4 is cut off, the optocoupler U4 is turned on, the optocoupler U4 emitter output low level passes through the resistance R90 to control the MOS tube Q5 to be cut off, at this time the 5V voltage charges the capacitor C10 through the resistance R40 and the resistance R20 to form an integral circuit 0, by adjusting the parameters, a smooth voltage value can be obtained on the capacitor C10, and the voltage value is controlled by the thyristor conduction angle, the main control chip U5 outputs a PWM signal from the 3-pin to drive the MOS tube Q1 according to the voltage value on the capacitor C10, so that the brightness of the LED is adjusted.

[0022] That is, by sampling the dimming signal of the thyristor dimmer, the thyristor conduction state is maintained through the thyristor freewheeling module, the conduction angle signal of the dimming signal is obtained through the thyristor sampling module, and the signal isolation processing of the isolation module is sent to the dimming control module to control the output PWM, so that changing the conduction angle of the thyristor is equivalent to changing the brightness of the LED. Since the thyristor dimming part is not connected with the live wire, whether it is 100% load or 10% load, the power supply can input complete AC signals through the zero line and the live line, and is not affected by the thyristor dimming part, the harmonic and PF value are well controlled, and the EMC standard of the power supply is met, and the power can be linearly output in any state of the thyristor dimming, and is not limited by the conduction angle of the thyristor. And during dimming, the dimming signal comes from the thyristor freewheeling module and the sampling module, and is not affected by the power size, regardless of the conduction angle of the thyristor dimmer, the dimming signal is stable, avoiding the difficulty of low brightness flicker in traditional thyristor dimming, and the response speed of dimming is fast, and the dimming can also be linear, because in the entire dimming range, the power supply is in normal working state, only the load changes.

[0023] Those skilled in the art can easily understand that the above preferred modes can be freely combined and superimposed without conflict.

[0024] The above is only a preferred embodiment of the utility model, and does not limit the patent range of the utility model, and any equivalent structural transformation made by using the utility model specification and the attached drawings, or direct or indirect application in other related technical fields is included in the patent protection range of the utility model.

Claims

1. A multi-in-one dimming circuit satisfying Class 2, characterized by, The utility model relates to a multi-in-one dimming module, and a multi-in-one dimming module includes at least one of a silicon controlled rectifier dimming module, a PWM dimming module, a DALI dimming module and a 0-10V dimming module, and the output channel (10) includes a sampling circuit (11), an amplification circuit (12), a comparison circuit (13), a signal control circuit (15), a switching circuit (16) and a power output end, the output end of the multi-in-one dimming module is electrically connected with the switching circuit to carry out dimming control, the output power of each output channel (10) is less than or equal to 100W, and the current is less than or equal to 5A. The power output end is electrically connected with the power input end and the switching circuit (16) respectively, the input end of the sampling circuit (11) is electrically connected with the power output end to sample the current signal of a load, the output end of the sampling circuit (11) is electrically connected with the input end of the amplification circuit (12) to amplify the current signal to obtain an amplified signal, the amplification circuit (12) is electrically connected with the comparison circuit (13) to compare the amplified signal with a reference signal to obtain a comparison signal, and the signal control circuit (15) is electrically connected with the comparison circuit (13) to control the on-off state of the switching circuit (16) according to the comparison signal to realize overload and short-circuit protection.

2. The multi-in-one dimming circuit satisfying Class 2 according to claim 1, characterized in that: The power output end includes a positive output end and a negative output end, the power input end includes a positive input end and a negative input end, the positive input end is electrically connected with the positive output end, the negative input end is grounded, the switching circuit (16) includes a MOS tube Q1, a resistor R1 and a resistor R2, the D pole of the MOS tube Q1 is electrically connected with the negative output end, the G pole of the MOS tube Q1 is electrically connected with one end of the resistor R2, the other end of the resistor R2 is electrically connected with one end of the resistor R1 and the signal control circuit (15) respectively, the other end of the resistor R1 is electrically connected with the power supply circuit to input a working voltage VCC, and the S pole of the MOS tube Q1 is electrically connected with the sampling circuit (11).

3. The multi-in-one dimming circuit satisfying Class 2 according to claim 2, characterized in that: The sampling circuit (11) includes a resistor R6, one end of the resistor R6 is electrically connected with the S pole of the MOS tube Q1 and the input end of the amplification circuit (12) respectively, and the other end of the resistor R6 is grounded.

4. The multi-in-one dimming circuit satisfying Class 2 according to claim 3, characterized in that: The amplification circuit (12) includes an operational amplifier U1, a resistor R8, a resistor R10 and a capacitor C4, the positive input end of the operational amplifier U1 is electrically connected with the sampling circuit (11) R6, the negative input end of the operational amplifier U1 is electrically connected with one end of the resistor R8, one end of the resistor R10 and one end of the capacitor C4 respectively, the other end of the resistor R8 and the other end of the capacitor C4 are electrically connected with the output end of the operational amplifier U1 respectively, the output end of the operational amplifier U1 is electrically connected with the comparison circuit (13), and the other end of the resistor R10 is grounded.

5. The multi-in-one dimming circuit satisfying Class 2 according to claim 1, characterized by: The comparison circuit (13) comprises a comparator U2, a resistor R5, a capacitor C1 and a reference circuit (131), the output of the amplification circuit (12) is connected with the positive input of the comparator U2 and one end of the capacitor C1 through the resistor R5 in series, the other end of the capacitor C1 is connected with the output of the comparator U2, the reference circuit (131) is connected with the negative input of the comparator U2, and the output of the comparator U2 is connected with the delay circuit.

6. The multi-in-one dimming circuit satisfying Class 2 according to claim 5, characterized in that: The reference circuit (131) comprises a resistor R9, a resistor R11 and a capacitor C5, one end of the resistor R9 is connected with the power supply circuit to input the working voltage VCC, the other end of the resistor R9 is connected with one end of the resistor R11, one end of the capacitor C5 and the negative input of the comparator U2 respectively, the other end of the resistor R11 and the other end of the capacitor C5 are grounded respectively.

7. The multi-in-one dimming circuit satisfying Class 2 according to claim 1, characterized by: The signal control circuit (15) comprises a MOS tube Q2, a diode D1, a resistor R7 and a capacitor C3, the anode of the diode D1 is connected with the output of the comparison circuit (13), the cathode of the diode D1 is connected with one end of the resistor R7, one end of the capacitor C3 and the G pole of the MOS tube Q2 respectively, the other end of the resistor R7, the other end of the capacitor C3 and the S pole of the MOS tube Q2 are grounded respectively, and the D pole of the MOS tube Q2 is connected with the switch circuit (16).

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