Detection system of LED driving power supply

Abstract

The utility model relates to the technical field of LED driving power supplies, in particular to a detection system of an LED driving power supply, which comprises a load condition detection unit, a two-in-one detection unit, a dummy load unit, a microcontroller unit and a main circuit of the LED driving power supply. The main circuit is used for generating voltage signals; the on-load condition detection unit is used for receiving the voltage signal, generating a level signal and transmitting the level signal to the microcontroller unit; the two-in-one detection unit is used for receiving the voltage signal, generating a short circuit detection signal and a load detection signal and transmitting the signals to the microcontroller unit; the dummy load unit is used for being connected in parallel with the output end of the main circuit after being controlled to be conducted by the microcontroller unit; the problems of circuit complexity and high power consumption caused by independent arrangement of a detection circuit and high power consumption caused by long-term parallel connection of dummy load circuits are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of LED driving power supplies, in particular to a detection system for an LED driving power supply. Background Art

[0002] In order to ensure that the LED lamp can be stably lit and dimmed under different load conditions, the LED driving power supply needs to be provided with a short-circuit protection circuit (used to execute the short-circuit protection strategy when detecting a short-circuit fault in the LED driving power supply), a load detection circuit (used to detect whether there is a load), a load condition detection circuit (used to detect the load condition, that is, the dimming condition), and a dummy load circuit connected in parallel at the output end (used to enhance the circuit current and improve the detection accuracy), so as to maintain the normal operation of the LED lamp, protect the LED lamp and the LED driving power supply, and extend the service life of the LED lamp and the LED driving power supply.

[0003] However, separately setting the short-circuit protection circuit, the load detection circuit, and the load condition detection circuit will result in a complex and repetitive circuit structure of the detection system of the LED driving power supply, with more components, and excessive power consumption. More importantly, the dummy load circuit is only required to enhance the circuit current and improve the detection accuracy when the output end of the LED driving power supply is dimmed by 1% - 30%. When the dimming is greater than 30%, the dummy load circuit is not required. Therefore, when the dummy load circuit is connected in parallel at the output end and is in a working state for a long time, the power consumption will be greatly increased when the dimming is greater than 30%. Summary of the Utility Model

[0004] Aiming at the above defects, the purpose of the utility model is to provide a detection system for an LED driving power supply, which solves the problems of complex circuit and large power consumption caused by separately setting the detection circuit, and the problem of large power consumption caused by the long-term parallel connection of the dummy load circuit.

[0005] To achieve this purpose, the utility model adopts the following technical solutions:

[0006] A detection system for an LED driving power supply includes a load condition detection unit, a two-in-one detection unit, a dummy load unit, a microcontroller unit, and the main circuit of the LED driving power supply; the input end of the load condition detection unit, the input end of the two-in-one detection unit, and the negative pole of the dummy load unit are all electrically connected to the output detection end of the main circuit, the positive pole of the dummy load unit is electrically connected to the positive pole of the main circuit, the output end of the load condition detection unit, the short-circuit detection output end and the load detection output end of the two-in-one detection unit are respectively electrically connected to the first input end, the second input end, and the third input end of the microcontroller unit, and the control end of the microcontroller unit is electrically connected to the control end of the dummy load unit;

[0007] The main circuit is used to generate a voltage signal;

[0008] The load condition detection unit is configured to receive the voltage signal and generate a level signal for transmission to the microcontroller unit;

[0009] The two-in-one detection unit is configured to receive the voltage signal and generate a short-circuit detection signal and a load detection signal for transmission to the microcontroller unit;

[0010] The dummy load unit is configured to be connected in parallel to the output end of the main circuit after being controlled by the microcontroller unit to be turned on.

[0011] Furthermore, the microcontroller unit is configured to control the dummy load unit to be turned on or off according to the level signal.

[0012] Furthermore, the two-in-one detection unit includes an operational amplifier U901B, a resistor R905, a resistor R906, a resistor R907, a diode D1, a diode D2, a short-circuit detection module, and a load detection module; one end of the resistor R907 serves as the input end of the two-in-one detection unit, the output end of the short-circuit detection module serves as the short-circuit detection output end of the two-in-one detection unit, and the output end of the load detection module serves as the load detection output end of the two-in-one detection unit;

[0013] The other end of the resistor R907 is electrically connected to the positive input terminal of the operational amplifier U901B, one end of the resistor R905 and one end of the resistor R906 are both electrically connected to the negative input terminal of the operational amplifier U901B, the other end of the resistor R906 is grounded, the other end of the resistor R905 and the cathode of the diode D2 are both electrically connected to the input end of the load detection module, the anodes of the diode D1 and the diode D2 are both electrically connected to the output end of the operational amplifier U901B, and the cathode of the diode D1 is electrically connected to the input end of the short-circuit detection module.

[0014] Furthermore, the load condition detection unit includes an operational amplifier U901A, a resistor R908, a resistor R909, a resistor R910, a resistor R911, a resistor R912, a resistor R913, a capacitor C903, a capacitor C905, and a capacitor C906; one end of the resistor R908 serves as the output end of the load condition detection unit, and one end of the resistor R912 serves as the input end of the load condition detection unit;

[0015] The other end of the resistor R912 and one end of the resistor R913 are both electrically connected to one end of the capacitor C905. The other end of the resistor R913 and one end of the resistor R911 are both electrically connected to one end of the capacitor C906. The other ends of the capacitor C905 and the capacitor C906 are both grounded. The other end of the resistor R911 is electrically connected to the positive input terminal of the operational amplifier U901A. One end of the resistor R909 and one end of the resistor R910 are both electrically connected to the negative input terminal of the operational amplifier U901A. The other end of the resistor R910 and the negative power supply of the operational amplifier U901A are both grounded. The other end of the resistor R908 and the other end of the resistor R909 are both electrically connected to the output terminal of the operational amplifier U901A. The positive power supply of the operational amplifier U901A and the capacitor C903 are both connected to an 8V power supply, and the other end of the capacitor C903 is grounded.

[0016] Further, the short-circuit detection module includes a resistor R901, a resistor R902, and a resistor R903. One end of the resistor R903 is used as the input terminal of the short-circuit detection module, and one end of the resistor R901 is used as the output terminal of the short-circuit detection module.

[0017] The other end of the resistor R903 and one end of the resistor R902 are both electrically connected to the other end of the resistor R901, and one end of the resistor R902 is grounded.

[0018] Further, the load detection module includes a resistor R904 and a capacitor C904. One end of the resistor R904 is used as the input terminal of the load detection module, and the other end of the resistor R904 is used as the output terminal of the load detection module.

[0019] The other end of the resistor R904 is electrically connected to one end of the capacitor C904, and the other end of the capacitor C904 is grounded.

[0020] Further, the dummy load unit includes a load module, a resistor R313, a resistor R314, and a MOS transistor Q304. One end of the resistor R313 is used as the control terminal of the dummy load unit. The source electrode of the MOS transistor Q304 is used as the negative electrode of the dummy load unit, and one end of the load module is used as the positive electrode of the dummy load unit.

[0021] The other end of the resistor R313 and one end of the resistor R314 are both electrically connected to the gate electrode of the MOS transistor Q304. The source electrode of the MOS transistor Q304 and the other end of the resistor R314 are both grounded, and the drain electrode of the MOS transistor Q304 is electrically connected to the other end of the load module.

[0022] Further, the load module includes at least one resistor R309; one end of the resistor R309 serves as one end of the load module, and the other end of the resistor R309 serves as the other end of the load module;

[0023] One ends of all the resistors R309 are commonly connected electrically, and the other ends of all the resistors R309 are commonly connected electrically.

[0024] Further, the main circuit includes a resistor R315, a resistor R316, a resistor R317, a resistor R318, a MOS transistor Q303, a TVS diode TVS301, an inductor M307, an inductor M308, a diode D303, a diode D304, a diode D305, a common-mode inductor LF301, a secondary-side rectifying output circuit of a transformer T1, and a dimming drive circuit; one end of the resistor R315 serves as an output detection end of the main circuit, the positive pole of the secondary-side rectifying output circuit of the transformer T1 serves as the positive pole of the main circuit, and the cathode and anode of the diode D305 serve as the positive dimming output end and the negative dimming output end of the main circuit respectively;

[0025] The other end of the resistor R315 is electrically connected to the negative pole of the secondary-side rectifying output circuit of the transformer T1. One end of the resistor R315, one end of the resistor R316, and one end of the TVS diode TVS301 are all electrically connected to the source electrode of the MOS transistor Q303. The other end of the resistor R316, one end of the resistor R317, and one end of the resistor R318 are all electrically connected to the gate electrode of the MOS transistor Q303. The other end of the resistor R317 is electrically connected to the anode of the diode D303. The cathode of the diode D303 and the other end of the resistor R318 are both electrically connected to the drive end of the dimming drive circuit. The drain electrode of the MOS transistor Q303 and one end of the inductor M307 are both electrically connected to one end of the inductor M308. The other end of the TVS diode TVS301, the anode of the diode D304, the second input end of the common-mode inductor LF301, and the other end of the inductor M307 are all electrically connected to the other end of the inductor M308. The cathode of the diode D304 and the first input end of the common-mode inductor LF301 are both electrically connected to the positive pole of the secondary-side rectifying output circuit of the transformer T1. The first output end and the second output end of the common-mode inductor LF301 are electrically connected to the cathode and anode of the diode D305 respectively.

[0026] The technical solution provided by the present utility model may include the following beneficial effects:

[0027] 1. The signal acquisition can be achieved by sharing one output detection terminal for the three detections of short - circuit detection, load - carrying detection, and load - carrying condition detection, which simplifies the sampling circuit and reduces the circuit power consumption. At the same time, the two - in - one detection unit integrates the short - circuit detection and load - carrying detection circuits, further streamlining the detection circuit and reducing the circuit power consumption.

[0028] 2. Based on the three detection signals of level signal, short - circuit detection signal, and load - carrying detection signal, the micro - controller unit can select the timing of multiple parallel - connected dummy load units at the main - circuit output terminal, so as to enhance the detection current, improve the detectability while reducing the power consumption generated by the dummy load units. Moreover, the selective parallel connection of the dummy load units can be further utilized to maintain the stability of the operation. Description of the Drawings

[0029] Figure 1 It is the schematic diagram of a detection system for an LED driver power supply of one embodiment of the present utility model.

[0030] Figure 2 It is as Figure 1 shown, the circuit diagram of the two - in - one detection unit.

[0031] Figure 3 It is as Figure 1 shown, the circuit diagram of the load - carrying condition detection unit.

[0032] Figure 4 It is as Figure 1 shown, the circuit diagram of the dummy load unit.

[0033] Figure 5 It is as Figure 1 shown, the partial circuit diagram of the main circuit.

[0034] Wherein: main circuit 1, load condition detection unit 2, two-in-one detection unit 3, dummy load unit 4, microcontroller unit 5, operational amplifier U901B, resistor R905, resistor R906, resistor R907, diode D1, diode D2, short-circuit detection module 31, load detection module 32, operational amplifier U901A, resistor R908, resistor R909, resistor R910, resistor R911, resistor R912, resistor R913, capacitor C903, capacitor C905, capacitor C906, resistor R901, resistor R902, resistor R903, resistor R904, capacitor C904, load module 41, resistor R313, resistor R314, MOS transistor Q304, resistor R309, resistor R315, resistor R316, resistor R317, resistor R318, MOS transistor Q303, TVS diode TVS301, inductor M307, inductor M308, diode D303, diode D304, diode D305, common-mode inductor LF301, secondary-side rectification output circuit 11 of transformer T1, dimming drive circuit 12. Detailed implementation manners

[0035] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals indicate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

[0036] In the description of the embodiments of the present invention, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the embodiments of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0037] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific situations.

[0038] The following Figures 1 to 5 , describes a detection system for an LED drive power supply according to an embodiment of the present invention.

[0039] A detection system for an LED driving power supply, comprising a load condition detection unit 2, a two-in-one detection unit 3, a dummy load unit 4, a microcontroller unit 5, and a main circuit 1 of the LED driving power supply; the input end of the load condition detection unit 2, the input end of the two-in-one detection unit 3, and the negative pole of the dummy load unit 4 are all electrically connected to the output detection end of the main circuit 1, the positive pole of the dummy load unit 4 is electrically connected to the positive pole of the main circuit 1, the output end of the load condition detection unit 2, the short-circuit detection output end and the load detection output end of the two-in-one detection unit 3 are respectively electrically connected to the first input end, the second input end, and the third input end of the microcontroller unit 5, and the control end of the microcontroller unit 5 is electrically connected to the control end of the dummy load unit 4;

[0040] The main circuit 1 is used to generate a voltage signal;

[0041] The load condition detection unit 2 is used to receive the voltage signal and generate a level signal for transmission to the microcontroller unit 5;

[0042] The two-in-one detection unit 3 is used to receive the voltage signal and generate a short-circuit detection signal and a load detection signal for transmission to the microcontroller unit 5;

[0043] The dummy load unit 4 is used to be connected in parallel with the output end of the main circuit 1 after being controlled to conduct by the microcontroller unit 5.

[0044] In a preferred embodiment of the detection system for an LED driving power supply proposed by the present utility model, as Figure 1 shown, the load detection system uses the load condition detection unit 2 and the two-in-one detection unit 3 to receive the voltage signal from the output end of the main circuit 1 of the LED driving power supply; the load condition detection unit 2 converts it into a level signal for transmission to the microcontroller unit 5 (such as an MCU), and the microcontroller unit 5 can judge the load condition according to the level of the level signal (that is, the level of the level signal is positively correlated with the dimming size), and the microcontroller unit 5 can also convert the level signal into an output current value for display later (such as display on a display screen, browsing by a client, etc.); the two-in-one detection unit 3 converts it into a short-circuit detection signal (such as a suddenly increased signal can represent a short circuit) and a load detection signal (such as a continuous signal can represent a load) for transmission to the microcontroller unit 5, which are respectively used for judging whether the LED driving power supply is short-circuited and whether there is a load connected to the output end of the LED driving power supply; enabling signal acquisition with only one output detection end for the three detections, streamlining the sampling circuit, reducing the circuit power consumption, and at the same time, the two-in-one detection unit 3 integrates two detection circuits, further streamlining the detection circuit and reducing the circuit power consumption.

[0045] Finally, based on the three detection signals, namely the level signal, the short-circuit detection signal, and the load detection signal, the microcontroller unit 5 can select various timings for the parallel connection of the dummy load unit 4 to the output end of the main circuit 1, thereby enhancing the detected current, improving the detectability, reducing the power consumption generated by the dummy load unit 4, and further using the selective parallel connection of the dummy load unit 4 to maintain the stability of the operation; for example, according to the level of the level signal, when the level signal is low (such as 1%-30% dimming), the microcontroller unit 5 controls the dummy load unit 4 to be incorporated to enhance the detected current; for another example, according to the short-circuit detection signal, when a short-circuit fault occurs in the LED driver power supply and the short-circuit detection signal suddenly changes, the microcontroller unit 5 controls the dummy load unit 4 to disconnect the parallel connection to reduce the load and mitigate the short-circuit damage; other methods of using the three detection signals to control the dummy load unit 4 are within this scope and will not be described one by one here.

[0046] Furthermore, the microcontroller unit 5 is configured to control the conduction or cut-off of the dummy load unit 4 according to the level signal.

[0047] In this embodiment, based on the core function of the dummy load unit 4, which is to parallel the dummy load unit 4 to enhance the detected current and improve the detection accuracy when the output current of the LED driver power supply is weak, the microcontroller unit 5 preferably controls the conduction or cut-off of the dummy load unit 4 according to the level signal, and can freely determine when to turn on the dummy load unit 4 (such as 30% dimming, 25% dimming, etc.) to enhance the detected current when the output current is weaker than a certain value.

[0048] Furthermore, the two-in-one detection unit 3 includes an operational amplifier U901B, a resistor R905, a resistor R906, a resistor R907, a diode D1, a diode D2, a short-circuit detection module 31, and a load detection module 32; one end of the resistor R907 serves as the input end of the two-in-one detection unit 3, the output end of the short-circuit detection module 31 serves as the short-circuit detection output end of the two-in-one detection unit 3, and the output end of the load detection module 32 serves as the load detection output end of the two-in-one detection unit 3;

[0049] The other end of the resistor R907 is electrically connected to the positive input terminal of the operational amplifier U901B, one end of the resistor R905 and one end of the resistor R906 are both electrically connected to the negative input terminal of the operational amplifier U901B, the other end of the resistor R906 is grounded, the other end of the resistor R905 and the cathode of the diode D2 are both electrically connected to the input terminal of the load detection module 32, the anode of the diode D1 and the anode of the diode D2 are both electrically connected to the output terminal of the operational amplifier U901B, and the cathode of the diode D1 is electrically connected to the input terminal of the short-circuit detection module 31.

[0050] In this embodiment, as Figure 2As shown, the operational amplifier U901B, resistor R905, resistor R906, and resistor R907 form a non-inverting amplifier circuit to amplify the voltage signal, which is then used to generate a short-circuit detection signal by the short-circuit detection module 31 and a load detection signal by the load detection module 32 respectively. The amplification factor is set by resistors R905 and R906, and resistor R907 serves to limit the output current of the operational amplifier. It should be noted that diodes D1 and D2 can isolate the short-circuit detection module 31 and the load detection module 32 respectively to prevent signal interference between the two modules.

[0051] Further, the load condition detection unit 2 includes operational amplifier U901A, resistors R908, R909, R910, R911, R912, R913, capacitors C903, C905, and C906; one end of resistor R908 serves as the output end of the load condition detection unit 2, and one end of resistor R912 serves as the input end of the load condition detection unit 2;

[0052] The other end of resistor R912 and one end of resistor R913 are both electrically connected to one end of capacitor C905. The other end of resistor R913 and one end of resistor R911 are both electrically connected to one end of capacitor C906. The other ends of capacitor C905 and capacitor C906 are both grounded. The other end of resistor R911 is electrically connected to the positive input terminal of operational amplifier U901A. One end of resistor R909 and one end of resistor R910 are both electrically connected to the negative input terminal of operational amplifier U901A. The other end of resistor R910 and the negative power supply of operational amplifier U901A are both grounded. The other ends of resistor R908 and resistor R909 are both electrically connected to the output terminal of operational amplifier U901A. The positive power supply of operational amplifier U901A and capacitor C903 are both connected to the 8V power supply, and the other end of capacitor C903 is grounded.

[0053] In this embodiment, as Figure 3 shown, operational amplifier U901A and operational amplifier U901B similarly form a non-inverting amplifier circuit. After the voltage signal is shaped and filtered by the circuit at the positive input terminal of operational amplifier U901A, it is amplified to form a level signal. The level of the level signal changes with the voltage signal. Therefore, transmitting the level signal to the microcontroller unit 5 can identify the load condition.

[0054] Further, the short-circuit detection module 31 includes resistors R901, R902, and R903; one end of resistor R903 serves as the input end of the short-circuit detection module 31, and one end of resistor R901 serves as the output end of the short-circuit detection module 31;

[0055] The other end of resistor R903 and one end of resistor R902 are both electrically connected to the other end of resistor R901, and one end of resistor R902 is grounded.

[0056] In this embodiment, the short-circuit detection module 31 is composed of resistors R901, R902, and R903 to form a protection circuit for the port of the microcontroller unit 5, which is used to receive the output signal of the operational amplifier U901B. And because it does not pass through capacitor filtering, it is more sensitive to instantaneous waveform detection and has a faster response speed; therefore, it is used for short-circuit detection, and the circuit is simple and has low power consumption.

[0057] Furthermore, the load detection module 32 includes resistor R904 and capacitor C904; one end of resistor R904 is used as the input end of the load detection module 32, and the other end of resistor R904 is used as the output end of the load detection module 32;

[0058] The other end of resistor R904 is electrically connected to one end of capacitor C904, and the other end of capacitor C904 is grounded.

[0059] In this embodiment, the load detection module 32 is composed of resistor R904 and capacitor C904 to form a receiving circuit for the port of the microcontroller unit 5, which is used to receive the output signal of the operational amplifier U901B. Based on passing through capacitor filtering, some spike signals will be filtered out and will not flow to the microcontroller unit 5 for detection. Only signals such as dense and increasing in amplitude will cause the load detection signal to rise, and the response speed is slower; therefore, a continuous working signal after loading is required to cause a change in the load detection signal, which is suitable for load detection, and the circuit is simple and has low power consumption.

[0060] Furthermore, the dummy load unit 4 includes a load module 41, resistors R313, R314, and MOS transistor Q304; one end of resistor R313 is used as the control end of the dummy load unit 4, the source of MOS transistor Q304 is used as the negative pole of the dummy load unit 4, and one end of the load module 41 is used as the positive pole of the dummy load unit 4;

[0061] The other end of resistor R313 and one end of resistor R314 are both electrically connected to the gate of MOS transistor Q304, the source of MOS transistor Q304 and the other end of resistor R314 are both grounded, and the drain of MOS transistor Q304 is electrically connected to the other end of the load module 41.

[0062] In this embodiment, as Figure 4As shown, resistor R313, resistor R314 and MOS transistor Q304 form a switching circuit, which is controlled by the microcontroller unit 5. When MOS transistor Q304 is turned on, the load module 41 is connected in parallel to the output terminal of the main circuit 1; otherwise, it is disconnected, without adding a load to the main circuit 1. It should be noted that the load module 41 can be various types of loads, such as electrical devices, load components, etc., which are not limited here.

[0063] Further, the load module 41 includes at least one resistor R309; one end of the resistor R309 is used as one end of the load module 41, and the other end of the resistor R309 is used as the other end of the load module 41;

[0064] One ends of all the resistors R309 are connected in common point electrically, and the other ends of all the resistors R309 are connected in common point electrically.

[0065] In this embodiment, in order to facilitate the integration of the load module 41 into the circuit and reduce the area occupied by the load module 41 on the circuit board, the load module 41 is preferably composed of the resistor R309, and the number of resistors R309 connected in parallel to form the load module 41 can be freely selected according to the load size requirements.

[0066] Further, the main circuit 1 includes resistor R315, resistor R316, resistor R317, resistor R318, MOS transistor Q303, TVS diode TVS301, inductor M307, inductor M308, diode D303, diode D304, diode D305, common mode inductor LF301, the secondary side rectifier output circuit 11 of transformer T1 and the dimming drive circuit 12; one end of the resistor R315 is used as the output detection terminal of the main circuit 1, the positive pole of the secondary side rectifier output circuit 11 of transformer T1 is used as the positive pole of the main circuit 1, and the cathode and anode of the diode D305 are used as the positive dimming output terminal and the negative dimming output terminal of the main circuit 1 respectively;

[0067] The other end of resistor R315 is electrically connected to the negative pole of the rectifier output circuit 11 on the secondary side of transformer T1. One end of resistor R315, one end of resistor R316, and one end of TVS tube TVS301 are all electrically connected to the source electrode of MOS tube Q303. The other end of resistor R316, one end of resistor R317, and one end of resistor R318 are all electrically connected to the gate electrode of MOS tube Q303. The other end of resistor R317 is electrically connected to the anode of diode D303. The cathode of diode D303 and the other end of resistor R318 are both electrically connected to the driving end of the dimming driving circuit 12. The drain electrode of MOS tube Q303 and one end of inductor M307 are both electrically connected to one end of inductor M308. The other end of TVS tube TVS301, the anode of diode D304, the second input terminal of common mode inductor LF301, and the other end of inductor M307 are all electrically connected to the other end of inductor M308. The cathode of diode D304 and the first input terminal of common mode inductor LF301 are both electrically connected to the positive pole of the rectifier output circuit 11 on the secondary side of transformer T1. The first output terminal and the second output terminal of common mode inductor LF301 are respectively electrically connected to the cathode and the anode of diode D305.

[0068] In this embodiment, the output of the LED driving power supply generally needs to be transformed by transformer T1, and the dimming function is realized by the switching of the chopper switch (MOS tube Q303), as Figure 5 shown. Therefore, resistor R315 is arranged between the source electrode of MOS tube Q303 and the ground terminal (SGND) to sample the current signal flowing back to the ground terminal (SGND) of MOS tube Q303 during the chopper switching process. Resistor R315 converts the current signal that is not easy to collect into a voltage signal for the subsequent three detections, accurately reflecting the working state of the LED driving power supply.

[0069] For those of ordinary skill in the art, other components and operations of the detection system of an LED driving power supply according to an embodiment of the present invention are known, and will not be described in detail here.

[0070] In the description of this specification, the descriptions referring to the terms "embodiment", "example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0071] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A detection system for an LED driving power supply, characterized in that: A main circuit including a load condition detection unit, a two-in-one detection unit, a dummy load unit, a microcontroller unit, and an LED driving power supply; the input end of the load condition detection unit, the input end of the two-in-one detection unit, and the negative pole of the dummy load unit are all electrically connected to the output detection end of the main circuit, the positive pole of the dummy load unit is electrically connected to the positive pole of the main circuit, the output end of the load condition detection unit, the short-circuit detection output end and the load detection output end of the two-in-one detection unit are respectively electrically connected to the first input end, the second input end, and the third input end of the microcontroller unit, and the control end of the microcontroller unit is electrically connected to the control end of the dummy load unit; The main circuit is used to generate a voltage signal; The load condition detection unit is used to receive the voltage signal and generate a level signal for transmission to the microcontroller unit; The two-in-one detection unit is used to receive the voltage signal and generate a short-circuit detection signal and a load detection signal for transmission to the microcontroller unit; The dummy load unit is used to be connected in parallel with the output end of the main circuit after being controlled to conduct by the microcontroller unit.

2. The detection system of an LED driving power supply according to claim 1, characterized in that: The microcontroller unit is used to control the dummy load unit to conduct or cut off according to the level signal.

3. The detection system of an LED driving power supply according to claim 1, characterized in that: The two-in-one detection unit includes an operational amplifier U901B, a resistor R905, a resistor R906, a resistor R907, a diode D1, a diode D2, a short-circuit detection module, and a load detection module; one end of the resistor R907 serves as the input end of the two-in-one detection unit, the output end of the short-circuit detection module serves as the short-circuit detection output end of the two-in-one detection unit, and the output end of the load detection module serves as the load detection output end of the two-in-one detection unit; The other end of the resistor R907 is electrically connected to the positive input end of the operational amplifier U901B, one end of the resistor R905 and one end of the resistor R906 are both electrically connected to the negative input end of the operational amplifier U901B, the other end of the resistor R906 is grounded, the other end of the resistor R905 and the cathode of the diode D2 are both electrically connected to the input end of the load detection module, the anode of the diode D1 and the anode of the diode D2 are both electrically connected to the output end of the operational amplifier U901B, and the cathode of the diode D1 is electrically connected to the input end of the short-circuit detection module.

4. A detection system for an LED driving power supply according to claim 1, wherein: The load condition detection unit includes an operational amplifier U901A, a resistor R908, a resistor R909, a resistor R910, a resistor R911, a resistor R912, a resistor R913, a capacitor C903, a capacitor C905, and a capacitor C906; one end of the resistor R908 serves as the output end of the load condition detection unit, and one end of the resistor R912 serves as the input end of the load condition detection unit; The other end of the resistor R912 and one end of the resistor R913 are both electrically connected to one end of the capacitor C905. The other end of the resistor R913 and one end of the resistor R911 are both electrically connected to one end of the capacitor C906. The other ends of the capacitor C905 and the capacitor C906 are both grounded. The other end of the resistor R911 is electrically connected to the positive input terminal of the operational amplifier U901A. One end of the resistor R909 and one end of the resistor R910 are both electrically connected to the negative input terminal of the operational amplifier U901A. The other end of the resistor R910 and the negative power supply of the operational amplifier U901A are both grounded. The other ends of the resistor R908 and the resistor R909 are both electrically connected to the output terminal of the operational amplifier U901A. The positive power supply of the operational amplifier U901A and the capacitor C903 are both connected to the 8V power supply, and the other end of the capacitor C903 is grounded.

5. The detection system of an LED driving power supply according to claim 3, wherein: The short - circuit detection module includes the resistors R901, R902, and R903. One end of the resistor R903 is used as the input terminal of the short - circuit detection module, and one end of the resistor R901 is used as the output terminal of the short - circuit detection module. The other end of the resistor R903 and one end of the resistor R902 are both electrically connected to the other end of the resistor R901, and one end of the resistor R902 is grounded.

6. The detection system of an LED driving power supply according to claim 3, characterized in that: The load - carrying detection module includes the resistor R904 and the capacitor C904. One end of the resistor R904 is used as the input terminal of the load - carrying detection module, and the other end of the resistor R904 is used as the output terminal of the load - carrying detection module. The other end of the resistor R904 is electrically connected to one end of the capacitor C904, and the other end of the capacitor C904 is grounded.

7. The detection system of an LED driving power supply according to claim 1, characterized in that: The dummy load unit includes a load module, the resistors R313, R314, and the MOS transistor Q304. One end of the resistor R313 is used as the control terminal of the dummy load unit. The source electrode of the MOS transistor Q304 is used as the negative electrode of the dummy load unit. One end of the load module is used as the positive electrode of the dummy load unit. The other end of the resistor R313 and one end of the resistor R314 are both electrically connected to the gate electrode of the MOS transistor Q304. The source electrode of the MOS transistor Q304 and the other end of the resistor R314 are both grounded. The drain electrode of the MOS transistor Q304 is electrically connected to the other end of the load module.

8. The detection system of an LED driving power supply according to claim 7, wherein: The load module includes at least one resistor R309. One end of the resistor R309 is used as one end of the load module, and the other end of the resistor R309 is used as the other end of the load module. One ends of all the resistors R309 are electrically connected at a common point, and the other ends of all the resistors R309 are electrically connected at a common point.

9. The detection system of an LED driving power supply according to claim 1, characterized in that: The main circuit includes resistor R315, resistor R316, resistor R317, resistor R318, MOS transistor Q303, TVS diode TVS301, inductor M307, inductor M308, diode D303, diode D304, diode D305, common-mode inductor LF301, the secondary rectifier output circuit of transformer T1, and the dimming drive circuit; one end of resistor R315 is used as the output detection end of the main circuit, the positive electrode of the secondary rectifier output circuit of transformer T1 is used as the positive electrode of the main circuit, and the cathode and anode of diode D305 are respectively used as the positive dimming output end and negative dimming output end of the main circuit; The other end of resistor R315 is electrically connected to the negative electrode of the secondary rectifier output circuit of transformer T1. One end of resistor R315, one end of resistor R316, and one end of TVS diode TVS301 are all electrically connected to the source electrode of MOS transistor Q303. The other end of resistor R316, one end of resistor R317, and one end of resistor R318 are all electrically connected to the gate electrode of MOS transistor Q303. The other end of resistor R317 is electrically connected to the anode of diode D303. The cathode of diode D303 and the other end of resistor R318 are both electrically connected to the drive end of the dimming drive circuit. The drain electrode of MOS transistor Q303 and one end of inductor M307 are both electrically connected to one end of inductor M308. The other end of TVS diode TVS301, the anode of diode D304, the second input end of common-mode inductor LF301, and the other end of inductor M307 are all electrically connected to the other end of inductor M308. The cathode of diode D304 and the first input end of common-mode inductor LF301 are both electrically connected to the positive electrode of the secondary rectifier output circuit of transformer T1. The first output end and the second output end of common-mode inductor LF301 are respectively electrically connected to the cathode and anode of diode D305.

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