Power supply circuit meeting Class2 standard
By dividing the high-power power supply into multiple independent output channels and employing sampling, amplification, comparison, and signal control circuits, the problem of LED driver power supplies not meeting the Class 2 standard is solved, thereby improving safety and cost-effectiveness.
Patent Information
- Application Number
- CN202422749802.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-11
- Publication Date
- 2025-12-19
- Estimated Expiration
- 2034-11-11
AI Technical Summary
Existing high-power LED driver power supplies do not meet the Class 2 standard, posing safety hazards and incurring high costs. Using multiple power supplies of less than 100W or custom-made power supplies will increase wiring complexity and costs.
The high-power power supply is divided into multiple independent output channels, each with an output power of ≤100W and a current of ≤5A. Overload and short-circuit protection are achieved by using sampling, amplification, comparison and signal control circuits to form a multi-output power supply that meets the Class 2 standard.
It achieves independent protection for each output channel, improving safety and ease of use, reducing costs, and is suitable for LED driver applications.
Smart Images
Figure CN223694028U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to LED drive power supply technical field, especially a power circuit satisfying Class2 standard. 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 CLASS 2 considers current and energy. If confirmed as CLASS 2 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 Class2 output authentication, the following basic electrical properties need to be satisfied: the output voltage satisfies UL8750, and the output current and its power limit under 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 hazard in application. In order to improve safety and reliability, a plurality of power supplies less than 100W can be selected for application, or a power supply with multiple outputs and satisfying Class2 can be selected for application. Then the number of power supplies used in the former increases, the wiring becomes complex, and the cost also increases. The cost of the power supply in the latter is very high and not universal, which is equivalent to professional customization, and cannot meet the application requirements of 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 power circuit capable of changing a conventional power supply not satisfying Class2 into a low-cost power supply satisfying Class2 standard.
[0004] The power supply circuit satisfying the Class 2 standard according to the embodiment of the present application comprises a power input end and a plurality of mutually independent output channels, the output channel comprises a sampling circuit, an amplification circuit, a comparison circuit, a signal control circuit, a switch circuit and a power output end, the output power of each output channel is ≤100W, and the current is ≤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 the 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 power supply circuit satisfying the Class 2 standard according to the embodiment of the present application has at least the following beneficial effects: the present application divides a conventional power supply with large power into a plurality of independent output channels (each channel output power ≤100W, current ≤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 channels do not interfere with each other, so that a conventional power supply not satisfying Class 2 is changed into a multi-channel output power supply satisfying Class 2. For example, a 300W 24V power supply is changed into four independent output channels of 100W, 30W, 80W and 90W, each output channel works independently, and if the 30W output channel is overloaded, the 30W output channel will be protected according to the comparison signal, and the other three channels work normally, which is equivalent to obtaining four or even more independent power supplies satisfying Class 2 with overload or short circuit protection, which makes it more convenient to apply LED. Even if the conventional 300W power supply does not have overload or short circuit protection, the independent protection of each output channel can be met after the circuit transformation, which is equivalent to that the 300W conventional power supply also has overload protection function, improves the safety of application, is more convenient in LED driving application and has lower cost.
[0006] Additional aspects and advantages of the present application will be described in the following description, some of which will become apparent to those skilled in the art from the following description. BRIEF DESCRIPTION OF DRAWINGS
[0007] The specific embodiments of the present application will be further described below with reference to the accompanying drawings;
[0008] Fig. 1 is a principle block diagram of the power supply circuit satisfying the Class 2 standard;
[0009] Fig. 2 is a circuit schematic diagram of a power supply circuit satisfying Class 2 standard. DETAILED DESCRIPTION
[0010] This part will describe the specific embodiments of the utility model in detail, the preferred embodiments of the utility model 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 utility model, but it cannot be understood as the limitation of the protection scope of the utility model.
[0011] In the description of the utility model, it is understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc., is based on the orientation or position relationship shown in the drawings, only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as the limitation of the utility model.
[0012] In the description of the utility model, the meaning of several is one or more, the meaning of multiple is more than two, greater than, less than, more than, etc. are understood as not including the number, above, below, etc. are understood as including the number. If the first, the second is described, it is only used for distinguishing technical features for the purpose, 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.
[0013] Referring to Figs. 1-2 , the utility model discloses a power supply circuit satisfying Class 2 standard, comprising power input end, power supply circuit 20 and multiple independent output channels 10, output channel 10 includes sampling circuit 11, amplifier circuit 12, comparison circuit 13, signal control circuit 15, switch circuit 16 and power output end, power supply circuit 20 is electrically connected with power input end to convert input voltage into working voltage to power sampling circuit 11, amplifier circuit 12, comparison circuit 13, signal control circuit 15 and switch circuit 16 respectively;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 switch 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 load, the output end of the sampling circuit 11 is electrically connected with the input end of the amplifier circuit 12 to amplify the current signal obtained by sampling to obtain an amplified signal, the amplifier circuit 12 is electrically connected with the comparison circuit 13 to compare the amplified signal with the reference signal to obtain a comparison signal, the signal control circuit 15 is electrically connected with the comparison circuit 13 to control the on-off state of the switch circuit 16 according to the comparison signal to realize overload and short-circuit protection.
[0014] The utility model discloses a conventional power supply of one big power is divided into meeting the multiple independent output channel 10 of Class2 (every channel output power is less than or equal to 100W, current is less than or equal to 5A), and the output power of every output channel 10 can be independently set through the parameter of sampling module change, and do not interfere with each other, i. e. the conventional power supply of one not meeting Class2 becomes a multiple output power supply meeting Class2. Such as 1 100W, 1 30W, 1 80W, 1 90W four independent output channel 10 of 24V power supply of 300W, every output channel 10 independently works, suppose 30W overload among them, then 30W output channel 10 will carry out overload protection according to comparison signal, and other three channels work normally, equivalent to obtained four or even more independent power supply meeting Class2 with overload or short-circuit protection, this will make the application LED more convenient. Even if this 300W conventional power supply does not have overload or short-circuit protection, can meet the independent protection of every output channel 10 through such circuit transformation, and 300W conventional power supply also has overload protection function equivalently, improves the security of application, and it is more convenient in LED drive application, and the cost is lower.
[0015] As shown in Fig. 2 In specific application, including four output channels 10, the power supply output end of every output channel 10 includes positive output end and negative output end, and the power supply input end includes positive input end and negative input end, and the power supply input end can be constant voltage or constant current, the positive input end is electrically connected with four positive output ends respectively, four negative input ends are grounded, and the power supply circuit 20 can be DC-DC topology structure, as shown in Fig. 2The linear LDO output operating voltage VCC is used to power each circuit. The circuit structure of each of the four output channels 10 is the same, except that the specific parameters in the circuit are different according to the respective power. Taking the specific circuit of one of the output channels 10 as an example: the switching circuit 16 includes a MOS transistor Q1, a resistor R1 and a resistor R2. The D terminal of the MOS transistor Q1 is electrically connected to the negative output terminal. The G terminal of the MOS transistor Q1 is electrically connected to one end of the resistor R2. The other end of the resistor R2 is electrically connected to one end of the resistor R1 and the signal control circuit 15, respectively. The other end of the resistor R1 is electrically connected to the power supply circuit 20 to input the operating voltage VCC. The S terminal of the MOS transistor Q1 is electrically connected to the sampling circuit 11. The sampling circuit 11 includes a resistor R6. One end of the resistor R6 is electrically connected to the S terminal of the MOS transistor Q1 and the input terminal of the amplifying circuit 12, respectively. 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 terminal of the operational amplifier U1 is electrically connected to the R6 of the sampling circuit 11. The negative input terminal of the operational amplifier U1 is electrically connected to 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 to the output terminal of the operational amplifier U1, respectively. The output terminal of the operational amplifier U1 is electrically connected to the comparison circuit 13. The other end of the resistor R10 is grounded. The comparison circuit 13 includes a comparator U2, a resistor R5, a capacitor C1 and a reference circuit 13. The output terminal of the amplifying circuit 12 is electrically connected to the positive input terminal of the comparator U2 and one end of the capacitor C1 through the series-connected resistor R5, respectively. The other end of the capacitor C1 is electrically connected to the output terminal of the comparator U2. The reference circuit 13 is electrically connected to the negative input terminal of the comparator U2. The output terminal of the comparator U2 is electrically connected to the delay circuit 14.
[0016] The reference circuit 13 includes a resistor R9, a resistor R11 and a capacitor C5. One end of the resistor R9 is electrically connected to the power supply circuit 20 to input the operating voltage VCC. The other end of the resistor R9 is electrically connected to one end of the resistor R11, one end of the capacitor C5 and the negative input terminal 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 transistor 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 to the output terminal of the comparison circuit 13. The cathode of the diode D1 is electrically connected to one end of the resistor R7, one end of the capacitor C3 and the G terminal of the MOS transistor Q2, respectively. The other end of the resistor R7, the other end of the capacitor C3 and the S terminal of the MOS transistor Q2 are grounded, respectively. The D terminal of the MOS transistor Q2 is electrically connected to the switching circuit 16.
[0017] 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 to meet 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 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.
[0018] 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 still outputs zero. At this time, the comparator U2 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 the overload. If the power output terminal is in a short circuit state, Q1 will be turned off again in an instant when 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.
[0019] The utility model discloses reduce the threshold of CLASS2 application, and the ordinary power supply and CLASS2 principle are combined, and CLASS2 application is realized, and the LED overload application is effectively protected, the suitable 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.
[0020] Those skilled in the art can understand that the above preferred modes can be freely combined and superimposed without conflict.
[0021] The above is only the 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 drawing contents, or direct or indirect application in other related technical fields is included in the patent protection range of the utility model.
Claims
1. A power supply circuit satisfying Class 2 standards, characterized by comprising: The application relates to a power supply input end and a plurality of mutually independent output channels (10), the output channels (10) comprising a sampling circuit (11), an amplification circuit (12), a comparison circuit (13), a signal control circuit (15), a switching circuit (16) and a power supply output end, the output power of each of the output channels (10) being less than or equal to 100 W and the current being less than or equal to 5 A; the power supply output end is electrically connected with the power supply input end and the switching circuit (16) respectively, the input end of the sampling circuit (11) is electrically connected with the power supply 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 sampled 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. The power supply output end comprises a positive output end and a negative output end, the power supply input end comprises 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) comprises 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 a 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).
2. The power supply circuit satisfying Class 2 standards according to claim 1, characterized by: The sampling circuit (11) comprises 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.
3. The power supply circuit satisfying Class 2 standards according to claim 2, characterized by: The amplification circuit (12) comprises 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.
4. The power supply circuit satisfying Class 2 standards according to claim 3, characterized by: The comparison circuit (13) comprises a comparator U2, a resistor R5, a capacitor C1 and a reference circuit (131), the output end of the amplification circuit (12) is electrically connected with the positive input end of the comparator U2 and one end of the capacitor C1 through the resistor R5 in series connection, the other end of the capacitor C1 is electrically connected with the output end of the comparator U2, the reference circuit (131) is electrically connected with the negative input end of the comparator U2, and the output end of the comparator U2 is electrically connected with a delay circuit.
5. The power supply circuit satisfying Class 2 standards according to claim 1, characterized by: 6. The power supply circuit satisfying Class 2 standards according to claim 5, characterized by: The reference circuit (131) comprises a resistor R9, a resistor R11 and a capacitor C5, one end of the resistor R9 is electrically connected with the power supply circuit to input the working 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.
7. The power supply circuit satisfying Class 2 standards 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 electrically connected with the output end of the comparison 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 switch circuit (16).