Multi-output switching power supply

Abstract

The utility model relates to the technical field of switching power supplies, in particular to a multiplexed output switching power supply, which comprises a main loop, a microcontroller and at least one group of output loops, the output loop comprises a PWM driving chip module, a light modulation output module and a color modulation output module. The output end of the secondary filter module of the main loop is used as a load anode, and the output ends of the dimming output module and the color modulation output module are used as load cathodes; the microcontroller is electrically connected with the PWM driving chip module, and transmits a dimming PWM signal and a toning PWM signal to the PWM driving chip module; and the input ends of the dimming output module and the color modulation output module are electrically connected with the dimming driving end and the color modulation driving end of the PWM driving module respectively. The circuit structure problem and the cost problem of expanding multi-path dimming and toning output are solved.

Description

Technical Field

[0001] This utility model relates to the field of switching power supply technology, and in particular to a multi-output switching power supply. Background Technology

[0002] Currently, the output of a switching power supply is located on the secondary winding of the transformer. After passing through the secondary winding filter module, a dimming chip (including PWM regulation, linear regulation, and digital regulation) and its peripheral circuits achieve single-channel dimming output. Simultaneous dimming and color adjustment are not possible. To increase color adjustment output, a color adjustment chip and its peripheral circuits need to be added to the secondary winding side of the transformer. Therefore, if multiple dimming and color adjustment outputs are to be added, more dimming and color adjustment chips and their peripheral circuits will be required, consuming a large number of chips and components, resulting in a complex circuit structure and huge costs. Utility Model Content

[0003] To address the aforementioned shortcomings, the purpose of this invention is to propose a multi-output switching power supply that solves the circuit structure and cost issues associated with expanding multi-channel dimming and color-tuning outputs.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] A multi-output switching power supply includes a main circuit, a microcontroller, and at least one set of output circuits; the output circuits include a PWM driver chip module, a dimming output module, and a color-tuning output module.

[0006] The output terminal of the secondary side filter module of the main circuit is used as the positive terminal of the load, and the output terminals of the dimming output module and the color-tuning output module are both used as the negative terminal of the load.

[0007] The microcontroller is electrically connected to the PWM driver chip module and transmits dimming PWM signals and color-tuning PWM signals to the PWM driver chip module; the input terminals of the dimming output module and the color-tuning output module are electrically connected to the dimming drive terminal and the color-tuning drive terminal of the PWM driver module, respectively.

[0008] Furthermore, it also includes a switching module, and the output circuit further includes two current detection modules; the microcontroller is electrically connected to the PFC module of the main circuit via the switching module, the microcontroller is electrically connected to the dimming output module via one of the current detection modules, and the microcontroller is also electrically connected to the color tone output module via the other current detection module;

[0009] When the microcontroller detects through the current detection module that the load regulation degree of the dimming output module or the color adjustment output module is less than 5%, the microcontroller drives the switching module to shut down the PFC module of the main circuit.

[0010] Furthermore, the output circuit also includes two short-circuit detection modules; the microcontroller is electrically connected to the dimming output module via one of the short-circuit detection modules, and the microcontroller is also electrically connected to the color-tuning output module via the other short-circuit detection module;

[0011] When the microcontroller detects a short circuit in the dimming output module or the color tone output module through the short circuit detection module, the microcontroller performs a short circuit protection action.

[0012] Furthermore, the dimming output module and the color-tuning output module have the same circuit structure;

[0013] The dimming output module includes resistors R97, R98, and R82, a MOSFET Q11, a diode D13, a capacitor CB1, and an inductor LF4B. One end of resistor R97 is used as the input terminal of the dimming output module, one end and the other end of inductor LF4B are both used as the output terminal of the dimming output module, and one end and the other end of resistor R82 are both electrically connected to the current detection module or the short-circuit detection module.

[0014] The other end of resistor R97 and one end of resistor R98 are both electrically connected to the gate of MOSFET Q11. The other end of resistor R98 is grounded. The drain of MOSFET Q11, one end of capacitor CB1, and the anode of diode D13 are all electrically connected to the other end of inductor LF4B. The other end of capacitor CB1 and the cathode of diode D13 are both connected to the power supply voltage. The source of MOSFET Q11 is electrically connected to one end of resistor R82. The other end of resistor R82 is grounded.

[0015] Furthermore, the current detection module includes resistors R100, R102, R103, R101, R107, and amplifier U9B; the output terminal of amplifier U9B is connected in series with resistor R100 and then electrically connected to the microcontroller; the positive input terminal of amplifier U9B is connected in series with resistor R101 and then electrically connected to one end of resistor R82; the negative input terminal of amplifier U9B is connected in series with resistor R103 and then electrically connected to the other end of resistor R82; resistor R107 is connected in parallel between the positive input terminal of amplifier U9B and ground; resistor R102 is connected in parallel between the negative input terminal and the output terminal of amplifier U9B.

[0016] Furthermore, the short-circuit detection module includes resistors R64, R65, and R68, diode D20, resistors R39, R52, R96, and R108, and amplifier U9A. The output terminal of amplifier U9A is electrically connected to the anode of diode D20. The cathode of diode D20 is connected to the microcontroller via series connection of resistors R65 and R64. Resistor R68 is connected in parallel between the common junction of resistors R65 and R64 and ground. The positive input terminal of amplifier U9A is connected in series with resistor R96 and then electrically connected to one end of resistor R82. The negative input terminal of amplifier U9A is connected in series with resistor R52 and then electrically connected to the other end of resistor R82. Resistor R108 is connected in parallel between the positive input terminal of amplifier U9A and ground. Resistor R39 is connected in parallel between the negative input terminal and the output terminal of amplifier U9A.

[0017] Furthermore, the switching module includes resistors R109, R110, R111, R112, and an optocoupler U15; the anode of the light-emitting diode of the optocoupler U15 is connected in series with resistor R109 and then electrically connected to the microcontroller; the cathode of the light-emitting diode of the optocoupler U15 is grounded; the collector of the photodetector of the optocoupler U15 is connected in series with resistor R112 and then electrically connected to the power supply terminal of the PFC module of the main circuit; the emitter of the photodetector of the optocoupler U15 is connected in series with resistor R111 and then electrically connected to the feedback terminal of the PFC module of the main circuit; and resistor R110 is connected in parallel between the emitter of the photodetector of the optocoupler U15 and ground.

[0018] The technical solution provided by this utility model can include the following beneficial effects: It adds at least one set of output circuits controlled by a microcontroller, and the output circuits (WLED-, CLED-) and the secondary-side filter module output terminal (LED+) of the main circuit of the switching power supply are connected to the load (such as light strips, lamps, lamp circuits, etc.) to achieve multi-channel output dimming and color adjustment; in addition, each set of output circuits receives dimming PWM signals and color adjustment PWM signals from the microcontroller (such as MCU) through a PWM driver chip module, and drives the dimming output module to achieve dimming and the color adjustment output module to achieve color adjustment respectively. Each set of output circuits can achieve dimming and color adjustment simultaneously using only one chip in the PWM driver chip module, greatly reducing the amount of chips and components used, simplifying the circuit structure, and lowering the cost. Attached Figure Description

[0019] Figure 1 This is one embodiment of the principle of a multi-output switching power supply. Figure 1 .

[0020] Figure 2 Is it like this? Figure 1 The circuit diagram of the PWM driver chip module is shown.

[0021] Figure 3 Is it like this? Figure 1 The following describes the principle of a multi-output switching power supply. Figure 2 .

[0022] Figure 4 Is it like this? Figure 1 The circuit diagrams for the dimming output module and the color grading output module are shown.

[0023] Figure 5 Is it like this? Figure 3 The circuit diagram of the current detection module is shown.

[0024] Figure 6 Is it like this? Figure 3 The circuit diagram of the short-circuit detection module is shown.

[0025] Figure 7 Is it like this? Figure 1 The circuit diagram of the switch module shown is shown.

[0026] The components include: main circuit 1, microcontroller 5, PWM driver chip module 2, dimming output module 3, color adjustment output module 4, switch module 6, current detection module 7, short circuit detection module 8, resistors R97, R98, and R82, MOSFET Q11, diode D13, capacitor CB1, inductor LF4B, resistors R100, R102, R103, R101, and R107, amplifier U9B, resistors R64, R65, and R68, diode D20, resistor R39, resistor R52, resistor R96, and resistor R108, amplifier U9A, resistors R109, R110, R111, and R112, and optocoupler U15. Detailed Implementation

[0027] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0028] In the description of embodiments of this utility model, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of embodiments of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0029] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this utility model according to the specific circumstances.

[0030] The following is combined Figures 1 to 7 This describes a multi-output switching power supply according to an embodiment of the present invention.

[0031] A multi-output switching power supply includes a main circuit 1, a microcontroller 5, and at least one set of output circuits; the output circuits include a PWM driver chip module 2, a dimming output module 3, and a color-tuning output module 4.

[0032] The output of the secondary filter module of the main circuit 1 is used as the positive terminal of the load, and the outputs of the dimming output module 3 and the color-tuning output module 4 are both used as the negative terminals of the load.

[0033] The microcontroller 5 is electrically connected to the PWM driver chip module 2, and transmits dimming PWM signals and color-tuning PWM signals to the PWM driver chip module 2; the input terminals of the dimming output module 3 and the color-tuning output module 4 are electrically connected to the dimming drive terminal and the color-tuning drive terminal of the PWM driver module 5, respectively.

[0034] This utility model proposes a preferred embodiment of a multi-output switching power supply, such as... Figure 1As shown, at least one set of output circuits controlled by microcontroller 5 is added. The output circuits (WLED-, CLED-) and the output terminal (LED+) of the secondary side filter module of the main circuit 1 of the switching power supply are connected to the load (such as light strip, lamp, lamp circuit, etc.) to realize multi-channel output dimming and color adjustment. In addition, each set of output circuits receives dimming PWM signals and color adjustment PWM signals from microcontroller 5 (such as MCU) by PWM driver chip module 2, and drives dimming output module 3 to realize dimming and color adjustment output module 4 to realize color adjustment respectively. Each set of output circuits can realize dimming and color adjustment simultaneously using only one chip in PWM driver chip module 2, which greatly reduces the amount of chips and components used, simplifies the circuit structure, and reduces costs.

[0035] It should be noted that the PWM driver chip module 2 is optional. Figure 2 As shown, it consists of chip U12 and its peripheral circuits. The DRVH and DRVL terminals of chip U12 receive dimming PWM signals and color PWM signals, respectively. The INH and INL terminals of chip U12 are connected to dimming output module 3 and color PWM output module 4, respectively.

[0036] It should also be noted that the secondary-side filtering module of the main circuit 1 is usually used to rectify and filter the secondary-side signal of the transformer through an inductor, an RCD absorption circuit, and a filter inductor, and then output the VBUS voltage to provide to the positive terminal of the load (LED+).

[0037] Furthermore, it also includes a switch module 6, and the output circuit also includes two current detection modules 7; the microcontroller 5 is electrically connected to the PFC module of the main circuit 1 via the switch module 6, the microcontroller 5 is electrically connected to the dimming output module 3 via one of the current detection modules 7, and the microcontroller 5 is also electrically connected to the color tone output module 4 via the other current detection module 7.

[0038] When the microcontroller 5 detects through the current detection module 7 that the load regulation degree of the dimming output module 3 or the color adjustment output module 4 is less than 5%, the microcontroller 5 drives the switch module 6 to shut down the PFC module of the main circuit 1.

[0039] When the load dimming or color adjustment is below 5%, the PFC module of main circuit 1 may switch from BCM (critical conduction mode) to DCM (discontinuous conduction mode), or the operating frequency may increase, resulting in severe electromagnetic interference (EMI) on the input safety and rectifier modules of main circuit 1 and poor EMI filtering performance. This is especially true when the switching power supply has multiple outputs. Therefore, the PFC module needs to be turned off at this time to improve the stability of the switching power supply.

[0040] Therefore, in this embodiment, as Figure 1 and 3As shown, by setting the switch module 6 and the current detection module 7, when the dimming or color adjustment degree is lower than 5% (taking dimming as an example, that is, the brightness is lower than 5%), the microcontroller 5 identifies and drives the switch module 6 to shut down the PFC module of the main circuit 1.

[0041] Furthermore, the output circuit also includes two short-circuit detection modules 8; the microcontroller 5 is electrically connected to the dimming output module 3 via one of the short-circuit detection modules 8, and the microcontroller 5 is also electrically connected to the color-tuning output module 4 via the other short-circuit detection module 8.

[0042] When the microcontroller 5 detects a short circuit in the dimming output module 3 or the color adjustment output module 4 through the short circuit detection module 8, the microcontroller 5 performs a short circuit protection action.

[0043] In this embodiment, since the switching power supply has multiple dimming and color-tuning outputs, a short circuit in any one output could cause the power supply to burn out, significantly increasing the probability of burnout. Therefore, a short-circuit detection module 8 is added to each output, which is then identified and executed by the microcontroller 5 to improve the safety and reliability of the switching power supply. Specifically, the short-circuit protection action can be that the microcontroller 5 stops transmitting dimming PWM signals and color-tuning PWM signals to the PWM driver chip module 2 to shut down the power supply output; the form of the short-circuit protection action is not limited here.

[0044] Furthermore, the dimming output module 3 and the color-tuning output module 4 have the same circuit structure;

[0045] The dimming output module 3 includes resistors R97, R98, and R82, MOSFET Q11, diode D13, capacitor CB1, and inductor LF4B. One end of resistor R97 is used as the input terminal of the dimming output module 3, and one and the other ends of inductor LF4B are used as the output terminals of the dimming output module 3. One and the other ends of resistor R82 are electrically connected to the current detection module 7 or the short circuit detection module 8.

[0046] The other end of resistor R97 and one end of resistor R98 are both electrically connected to the gate of MOSFET Q11. The other end of resistor R98 is grounded. The drain of MOSFET Q11, one end of capacitor CB1, and the anode of diode D13 are all electrically connected to the other end of inductor LF4B. The other end of capacitor CB1 and the cathode of diode D13 are both connected to the power supply voltage. The source of MOSFET Q11 is electrically connected to one end of resistor R82. The other end of resistor R82 is grounded.

[0047] In this embodiment, as Figure 4As shown, taking the dimming output module 3 as an example, it consists of resistors R97, R98, and R82, MOSFET Q11, diode D13, capacitor CB1, and inductor LF4B, which form a chopper circuit controlled by the dimming PWM signal to achieve load dimming. The circuit structure is simple and the cost is low. Similarly, the color tone output module 4 also forms a chopper circuit controlled by the color tone PWM signal to achieve load color tone.

[0048] It should be noted that capacitor CB1 and inductor LF4B serve as filters; diode D13 prevents excessive voltage spikes caused by the capacitive characteristics of the load (usually present in lighting fixtures) during transients such as power-on and short circuits. Diode D13 provides a path for voltage spikes, preventing breakdown of MOSFET Q11.

[0049] Furthermore, the current detection module 7 includes resistors R100, R102, R103, R101, R107, and amplifier U9B; the output terminal of amplifier U9B is connected to microcontroller 5 via resistor R100 in series; the positive input terminal of amplifier U9B is connected to one end of resistor R82 via resistor R101 in series; the negative input terminal of amplifier U9B is connected to the other end of resistor R82 via resistor R103 in series; resistor R107 is connected in parallel between the positive input terminal of amplifier U9B and ground; resistor R102 is connected in parallel between the negative input terminal and the output terminal of amplifier U9B.

[0050] In this embodiment, as Figure 5 As shown, the current detection module 7 identifies the current output current through the resistor R82 of the dimming output module 3 (or the resistor R85 of the color adjustment output module 4) to determine the adjustment degree. Therefore, the current detection module 7 consists of an operational amplifier circuit composed of resistors R100, R102, R103, R101, R107 and amplifier U9B to amplify the signal for recognition by the microcontroller 5.

[0051] Furthermore, the short-circuit detection module 8 includes resistors R64, R65, and R68, diode D20, resistors R39, R52, R96, and R108, and amplifier U9A. The output terminal of amplifier U9A is electrically connected to the anode of diode D20. The cathode of diode D20 is connected to microcontroller 5 after being connected in series with resistors R65 and R64. Resistor R68 is connected in parallel between the common junction of resistors R65 and R64 and ground. The positive input terminal of amplifier U9A is connected in series with resistor R96 and then electrically connected to one end of resistor R82. The negative input terminal of amplifier U9A is connected in series with resistor R52 and then electrically connected to the other end of resistor R82. Resistor R108 is connected in parallel between the positive input terminal of amplifier U9A and ground. Resistor R39 is connected in parallel between the negative input terminal and the output terminal of amplifier U9A.

[0052] In this embodiment, as Figure 6 As shown, the short-circuit detection module 8 and the current detection module 7 operate on the same principle, both using operational amplifier circuits to amplify the signal for the microcontroller 5 to recognize. However, based on short-circuit detection, resistors R64, R65, and R68, along with diode D20, are added to the output of amplifier U9A to form a protection circuit to prevent short circuits from impacting the microcontroller 5.

[0053] Furthermore, the switch module 6 includes resistors R109, R110, R111, R112, and an optocoupler U15; the anode of the light-emitting diode of the optocoupler U15 is connected to the microcontroller 5 via a series resistor R109; the cathode of the light-emitting diode of the optocoupler U15 is grounded; the collector of the photodetector of the optocoupler U15 is connected to the power supply terminal of the PFC module of the main circuit 1 via a series resistor R112; the emitter of the photodetector of the optocoupler U15 is connected to the feedback terminal of the PFC module of the main circuit 1 via a series resistor R111; and a resistor R110 is connected in parallel between the emitter of the photodetector of the optocoupler U15 and ground.

[0054] In this embodiment, as Figure 7 As shown, since the microcontroller 5 controls the PFC module located on the primary winding side of the main circuit 1, strong and weak current isolation is required. Therefore, the switching module 6 is preferably composed of an optocoupler U15 and its peripheral circuit. When the microcontroller 5 drives the light-emitting diode of the optocoupler U15 to conduct (via PFC-EN), the photodetector of the optocoupler U15 also conducts, grounding the power supply terminal of the PFC module (such as the VCC terminal of the PFC chip) (via PFC-VCC), thereby turning off the PFC module. At the same time, the turn-off signal is fed back to the feedback terminal of the PFC module (such as the FB terminal of the PFC chip) (via PFC-off), so that the PFC chip can identify the current state.

[0055] Other configurations and operations of a multi-output switching power supply according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0056] In this specification, the terms "embodiment," "example," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0057] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A multi-output switching power supply, characterized in that: It includes a main circuit, a microcontroller, and at least one set of output circuits; the output circuits include a PWM driver chip module, a dimming output module, and a color-tuning output module. The output terminal of the secondary side filter module of the main circuit is used as the positive terminal of the load, and the output terminals of the dimming output module and the color-tuning output module are both used as the negative terminal of the load. The microcontroller is electrically connected to the PWM driver chip module and transmits dimming PWM signals and color-tuning PWM signals to the PWM driver chip module; the input terminals of the dimming output module and the color-tuning output module are electrically connected to the dimming drive terminal and the color-tuning drive terminal of the PWM driver chip module, respectively.

2. The multi-output switching power supply according to claim 1, characterized in that: It also includes a switching module, and the output circuit further includes two current detection modules; the microcontroller is electrically connected to the PFC module of the main circuit via the switching module, the microcontroller is electrically connected to the dimming output module via one of the current detection modules, and the microcontroller is also electrically connected to the color tone output module via the other current detection module; When the microcontroller detects through the current detection module that the load regulation degree of the dimming output module or the color adjustment output module is less than 5%, the microcontroller drives the switching module to shut down the PFC module of the main circuit.

3. A multi-output switching power supply according to claim 2, characterized in that: The output circuit also includes two short-circuit detection modules; the microcontroller is electrically connected to the dimming output module via one of the short-circuit detection modules, and the microcontroller is also electrically connected to the color-tuning output module via the other short-circuit detection module; When the microcontroller detects a short circuit in the dimming output module or the color tone output module through the short circuit detection module, the microcontroller performs a short circuit protection action.

4. A multi-output switching power supply according to claim 3, characterized in that: The dimming output module and the color-correcting output module have the same circuit structure; The dimming output module includes resistors R97, R98, and R82, a MOSFET Q11, a diode D13, a capacitor CB1, and an inductor LF4B. One end of resistor R97 is used as the input terminal of the dimming output module, one end and the other end of inductor LF4B are both used as the output terminal of the dimming output module, and one end and the other end of resistor R82 are both electrically connected to the current detection module or the short-circuit detection module. The other end of resistor R97 and one end of resistor R98 are both electrically connected to the gate of MOSFET Q11. The other end of resistor R98 is grounded. The drain of MOSFET Q11, one end of capacitor CB1, and the anode of diode D13 are all electrically connected to the other end of inductor LF4B. The other end of capacitor CB1 and the cathode of diode D13 are both connected to the power supply voltage. The source of MOSFET Q11 is electrically connected to one end of resistor R82. The other end of resistor R82 is grounded.

5. A multi-output switching power supply according to claim 4, characterized in that: The current detection module includes resistors R100, R102, R103, R101, R107, and amplifier U9B. The output terminal of amplifier U9B is connected in series with resistor R100 and then electrically connected to the microcontroller. The positive input terminal of amplifier U9B is connected in series with resistor R101 and then electrically connected to one end of resistor R82. The negative input terminal of amplifier U9B is connected in series with resistor R103 and then electrically connected to the other end of resistor R82. Resistor R107 is connected in parallel between the positive input terminal of amplifier U9B and ground. Resistor R102 is connected in parallel between the negative input terminal and the output terminal of amplifier U9B.

6. A multi-output switching power supply according to claim 4, characterized in that: The short-circuit detection module includes resistors R64, R65, and R68, diode D20, resistors R39, R52, R96, and R108, and amplifier U9A. The output terminal of amplifier U9A is electrically connected to the anode of diode D20. The cathode of diode D20 is connected to the microcontroller via series connection of resistors R65 and R64. Resistor R68 is connected in parallel with ground between the common junction of resistors R65 and R64. The positive input terminal of amplifier U9A is connected in series with resistor R96 and then electrically connected to one end of resistor R82. The negative input terminal of amplifier U9A is connected in series with resistor R52 and then electrically connected to the other end of resistor R82. Resistor R108 is connected in parallel with ground between the positive input terminal of amplifier U9A. Resistor R39 is connected in parallel between the negative input terminal and the output terminal of amplifier U9A.

7. A multi-output switching power supply according to claim 2, characterized in that: The switching module includes resistors R109, R110, R111, R112, and an optocoupler U15. The anode of the light-emitting diode (LED) of the optocoupler U15 is connected in series with resistor R109 and then electrically connected to the microcontroller. The cathode of the LED of the optocoupler U15 is grounded. The collector of the photodetector of the optocoupler U15 is connected in series with resistor R112 and then electrically connected to the power supply terminal of the PFC module in the main circuit. The emitter of the photodetector of the optocoupler U15 is connected in series with resistor R111 and then electrically connected to the feedback terminal of the PFC module in the main circuit. Resistor R110 is connected in parallel between the emitter of the photodetector of the optocoupler U15 and ground.

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