MPPT flyback auxiliary source high-low voltage input power supply activation switching power supply circuit

Abstract

The utility model discloses an MPPT flyback auxiliary source high and low voltage input power supply activation switching power supply circuit comprising a DC input end used for receiving MPPT DC power supply input; and the input end of the primary auxiliary source input high-low voltage power supply activation switching power supply circuit is connected with the direct current input end. Automatic switching, isolation and stable power supply are realized through the R7, the R8, the C1, the ZD1, the OP1, the Q1 and the D2, and 12V-150V input is compatible. The problem that R1-R6 continuously emits heat and is burnt out within the range of 60V-150V after 12V-60V stable activation power supply is avoided, and the static loss is reduced. After the work of the IC is activated and stabilized, the OP1 optocoupler controls the Q1 PMOS tube to cut off power supply, overheating of the R1-R6 is prevented, a common 1206 chip resistor can be used, a high-power cement resistor is not needed, materials and PCB space are saved, and automatic switching and isolation of high-voltage input and low-voltage input are achieved.

Description

Technical Field

[0001] This invention relates to a power supply circuit, specifically to an MPPT flyback auxiliary source high and low voltage input power supply activation switching power supply circuit. Background Technology

[0002] For MPPT flyback auxiliary power supplies to operate at both high and low voltage inputs, they must be compatible with DC input voltages from 12V to 150V to start normally. However, it is difficult to find a suitable resistor value for the start-up resistor across a wide voltage range of 12V to 150V. This leads to incompatibility and conflict between controlling the activation voltage and managing the large amount of heat generated. It is necessary to use multiple start-up resistors and matching circuit control, which complicates the circuit or uses high-power cement resistors. This results in problems such as occupying PCBA space and generating a lot of heat, leading to PCBA space size conflicts that affect the design of product module circuits.

[0003] However, these solutions are often costly and have limited reliability, making them unsuitable for certain applications. Therefore, there is an urgent need for a simple, low-cost, and highly reliable MPPT flyback auxiliary power supply high / low voltage input activation switching circuit to meet product requirements. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides an MPPT flyback auxiliary power supply high / low voltage input power supply activation switching circuit. This circuit, through a simple design, enables automatic switching and isolation of high / low voltage input power supplies, ensuring stable operation of the equipment under various DC power supply conditions.

[0005] This invention is achieved through the following technical solution: an MPPT flyback auxiliary source high / low voltage input power supply activation switching power supply circuit, comprising:

[0006] DC input terminal, used to receive MPPT DC power input;

[0007] A primary auxiliary power source input high / low voltage power supply activation and switching circuit is provided, with its input terminal connected to the DC input terminal and its output terminal connected to the primary absorption circuit of a flyback basic topology. This circuit is used to automatically activate power supply within different input voltage ranges. The primary auxiliary power source input high / low voltage power supply activation and switching circuit includes:

[0008] A startup resistor, used for initial power supply, is connected in series between the DC input terminal and the source of Q1;

[0009] The PMOS transistor has its source connected to the DC input terminal and current limited by the start-up resistor, and its drain connected to the primary absorption circuit of the flyback basic topology.

[0010] Zener diodes ZD1 and ZD2 are used for voltage regulation control. ZD1 is connected between the gate of Q1 and ground, and ZD2 is connected between the DC input terminal and ground.

[0011] An optocoupler, whose input is connected to the secondary output circuit and whose output is connected to the gate of Q1, is used to turn off Q1 and cut off the power supply to the primary startup resistor after the IC has stabilized.

[0012] The primary absorption circuit of the basic flyback topology has its input terminal connected to the drain of the PMOS transistor and its output terminal connected to the main power voltage loop optocoupler control circuit to suppress voltage spikes during flyback switching.

[0013] The main power voltage loop optocoupler control circuit has its input terminal connected to the output terminal of the primary absorption circuit of the flyback basic topology, and its output terminal connected to the main power current loop detection and control circuit and the IC_VCC winding power supply circuit, which is used to stabilize the output voltage.

[0014] The main power current loop detection and control circuit has its input terminal connected to the output terminal of the main power voltage loop optocoupler control circuit, and its output terminal connected to the IC_VCC winding power supply circuit and the secondary multiple output circuit. It is used to detect the output current and adjust the working state.

[0015] The IC_VCC winding power supply circuit has its input terminal connected to the output terminal of the main power voltage loop optocoupler control circuit and the main power current loop detection and control circuit, and its output terminal connected to the IC to provide a stable working power supply.

[0016] The secondary multi-output circuit has its input terminal connected to the output terminal of the main power current loop detection and control circuit. It is used to provide multiple stable output voltages and control the power supply status of the PMOS transistors through feedback via an optocoupler.

[0017] As a preferred technical solution, the DC input terminal is connected to an MPPT solar panel or an on-board charging power supply to provide DC power, and provides initial power through current-limiting resistors R1-R6.

[0018] As a preferred technical solution, the start-up resistor is a 1206 chip resistor, one end of which is connected to the DC input terminal and the other end is connected to the source of the PMOS transistor.

[0019] As a preferred technical solution, the input terminal of the optocoupler is connected to the secondary multiple output circuit, the output terminal is connected to the gate of the PMOS transistor, and the drive signal is stabilized by a Zener diode to achieve automatic power supply switching.

[0020] As a preferred technical solution, R7, R8, C1, ZD1, OP1, Q1, and D2 are used to achieve automatic switching, isolation, and stable power supply for high and low voltage input power.

[0021] When the input voltage is 12V-60V, R1-R6 provide a stable power supply, and the PMOS transistor (Q1) is turned on;

[0022] When the input voltage is 60V-150V, after the secondary multiple output circuit is working, OP1 is turned on, which turns off Q1 and disconnects R1-R6.

[0023] As a preferred technical solution, after the IC is activated and stabilized, the optocoupler receives a feedback signal from the secondary multiplex output circuit, which controls the Q1 PMOS transistor to disconnect the power supply, so that R1-R6 stop continuously heating up.

[0024] As a preferred technical solution, the flyback circuit topology includes:

[0025] The transformer has its primary side connected to the drain of Q1 and its secondary side connected to the secondary multiple output circuit.

[0026] Diodes are used for secondary rectification.

[0027] Output capacitor, used to smooth the rectified output voltage.

[0028] As a preferred technical solution, the primary absorption circuit of the flyback basic topology absorbs high-frequency transient energy through the RCD clamping circuit, thereby reducing the voltage stress on the primary winding of the transformer.

[0029] The beneficial effects of this invention are as follows: This invention provides an MPPT primary auxiliary power supply activation and switching circuit for high and low voltage 12V-150V input power supply. Through R7, R8, C1, ZD1, OP1, Q1, and D2, it realizes automatic switching, isolation, and stable power supply for the flyback auxiliary power supply. This circuit has the advantages of simple operation, low cost, and high reliability. It can activate power supply for both high and low voltage 12V-150V inputs, avoiding the problem of R1-R6 continuously overheating and burning out when activating power supply at 60V-150V while ensuring stable activation power supply at 12V-60V. It also controls the static loss problem of 60V-150V input power supply.

[0030] After the IC is activated and stabilized, the circuit of this invention will disconnect the power supply to the Q1 PMOS transistor through the optocoupler OP1, thereby controlling the continuous heating of resistors R1-R6 and reducing input loss. R1-R6 can be made up of ordinary surface-mount 1206 resistors, without the need to use cement resistors or high-power plug-in resistors to deal with the heating problem of high voltage input, saving material costs and device space, and realizing automatic switching and isolation of high and low voltage input power supply. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is the circuit schematic diagram of the present invention. Detailed Implementation

[0033] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0034] Any feature disclosed in this specification (including any appended claims, abstract, and drawings) may be replaced by other equivalent or similar features, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0035] Figure 1 As shown, this invention provides an MPPT flyback auxiliary power supply high / low voltage input power activation and switching circuit. This circuit can automatically activate and switch power supply within a wide input voltage range of 12V-150V, improving the applicability and reliability of the power supply. Simultaneously, it optimizes the circuit structure, reducing power consumption and heat generation. Through a rationally designed power switching circuit, this solution ensures stable startup under low voltage input (12V-60V) while preventing continuous heating of the startup resistors R1-R6 under high voltage input (60V-150V), thereby reducing input losses and improving circuit reliability.

[0036] This circuit is suitable for applications such as MPPT solar charging systems, vehicle power systems, and industrial DC power supply systems, enabling efficient and stable DC power supply management.

[0037] In its implementation, the circuit consists of the following main modules: a DC input terminal, a primary auxiliary power supply input high / low voltage power supply activation and switching circuit, a flyback basic topology primary absorption circuit, a main power voltage loop optocoupler control circuit, a main power current loop detection and control circuit, an IC_VCC winding working power supply circuit, and a secondary multi-output circuit. These modules work together to achieve automatic switching, isolation, and stable power supply between high and low voltage inputs, ensuring that the equipment can start up and operate stably under different input voltage conditions.

[0038] During system operation, the DC input terminal receives input voltage from MPPT solar panels, vehicle chargers, or other DC power supply devices and supplies it to the entire circuit. To ensure the system can adapt to a wide voltage input range, the input terminal of the primary auxiliary power supply high / low voltage activation switching circuit is connected to the DC input terminal, and the output terminal is connected to the primary absorption circuit of the flyback basic topology. This circuit is mainly used to automatically activate the power supply within different input voltage ranges and ensure that the system maintains stable operation when the input voltage changes.

[0039] The primary auxiliary power input high / low voltage power supply activation switching circuit mainly consists of start-up resistors R1-R6, PMOS transistor Q1, Zener diodes ZD1 and ZD2, optocoupler OP1, and diode D2. Start-up resistors R1-R6 provide initial power and are connected in series between the DC input terminal and the source of Q1. At low input voltages (12V-60V), these resistors provide a stable initial power supply, allowing the system to start smoothly. However, at high input voltages (60V-150V), relying on R1-R6 for power would lead to excessive power consumption, causing the resistors to overheat or even fail. Therefore, optocoupler OP1 and Q1 are needed for coordinated control to achieve automatic switching.

[0040] After the system starts up normally, the secondary multiplexer circuit provides a feedback signal to optocoupler OP1, turning on the internal LED of OP1. This generates a low level at the optocoupler's output, causing the gate voltage of Q1 to drop to the cutoff state, turning Q1 off and cutting off the power supply path to the start-up resistors R1-R6. This effectively avoids the continuous overheating problem of R1-R6 under high-voltage input, while also reducing input power consumption. This allows R1-R6 to use ordinary 1206 surface-mount resistors instead of high-power cement resistors or through-hole resistors, thus saving material costs and optimizing PCB space layout. Furthermore, diode D2 is used to prevent reverse current when Q1 is turned off, protecting the MOSFET and improving circuit reliability.

[0041] After Q1 is turned off, the input of the primary absorption circuit in the flyback basic topology is connected to the drain of Q1, and the output is connected to the main power voltage loop optocoupler control circuit. This circuit is mainly used to absorb high-frequency transient energy and suppress voltage spikes during flyback switching to protect power components and ensure the stability of the power conversion process.

[0042] The input terminal of the main power voltage loop optocoupler control circuit is connected to the output terminal of the primary absorption circuit of the flyback basic topology, and the output terminal is connected to the main power current loop detection and control circuit and the IC_VCC winding working power supply circuit. Its function is to stabilize the output voltage and adjust the input power supply state through optocoupler feedback to ensure that the system can maintain a constant output voltage under different load conditions.

[0043] The input of the main power current loop detection and control circuit is connected to the output of the main power voltage loop optocoupler control circuit, and the output is connected to the IC_VCC winding power supply circuit and the secondary multiple output circuit. This module is used to detect the output current and dynamically adjust the system's operating state according to the load conditions to ensure the stability of the output voltage and current.

[0044] The input terminal of the IC_VCC winding power supply circuit is connected to the output terminals of the main power voltage loop optocoupler control circuit and the main power current loop detection and control circuit. Its function is to provide a stable power supply for the IC, ensuring the normal operation of the entire system. After system startup, this circuit will provide a continuous and stable power supply for the IC, no longer relying on the startup resistors R1-R6, thereby further reducing power consumption and improving system reliability.

[0045] The input of the secondary multiplexer circuit is connected to the output of the main power current loop detection and control circuit, primarily used to provide multiple stable output voltages to external loads. Furthermore, this circuit provides a feedback signal via optocoupler OP1 to control the power supply state of Q1, ensuring automatic switching and isolation between high and low voltage inputs. Under high voltage input, the optocoupler is on, Q1 is off, cutting off the power supply to R1-R6 to prevent overheating; under low voltage input, the optocoupler is off, Q1 is on, allowing the starting resistors R1-R6 to provide initial power, achieving stable startup.

[0046] In the entire system, the flyback circuit topology also includes key components such as transformer T1, rectifier diodes D5 and D6, and output capacitors C5 and C6. The primary side of transformer T1 is connected to the drain of Q1, and the secondary side is connected to the secondary multiplex output circuit.

[0047] When Q1 is turned on, the input power supply stores energy in the transformer, which is then released to the secondary side during the flyback process, providing a stable DC output to the load. Rectifier diodes D5 and D6 are used to rectify the AC signal, and output capacitors C5 and C6 are used for filtering, making the output voltage more stable and ensuring that the load can obtain a stable power supply.

[0048] Furthermore, the primary snubber circuit of the flyback basic topology absorbs high-frequency transient energy through an RCD clamping circuit, reducing voltage stress on the transformer primary winding, improving power conversion efficiency, and preventing damage to power components caused by high-frequency voltage spikes. This design further enhances system stability, making it suitable for a wider range of applications, including MPPT solar systems, on-board charging systems, and other 12V-150V DC power supply equipment.

[0049] This invention, through the aforementioned design, successfully solves problems such as high and low voltage input compatibility, startup resistor heating, high voltage static loss, and system power optimization, significantly improving the reliability and stability of power management. The circuit structure is simple and easy to implement, suitable for various application environments requiring efficient DC power supply, while reducing material costs and optimizing PCB space layout. It achieves more efficient power management while ensuring safe system operation.

[0050] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions conceived without inventive effort should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A MPPT flyback auxiliary source high and low voltage input power supply activation switching power supply circuit, characterized in that, include: DC input terminal, used to receive MPPT DC power input; A primary auxiliary power source input high / low voltage power supply activation and switching circuit is provided, with its input terminal connected to the DC input terminal and its output terminal connected to the primary absorption circuit of a flyback basic topology. This circuit is used to automatically activate power supply within different input voltage ranges. The primary auxiliary power source input high / low voltage power supply activation and switching circuit includes: A startup resistor, used for initial power supply, is connected in series between the DC input terminal and the source of Q1; The PMOS transistor has its source connected to the DC input terminal and current limited by the start-up resistor, and its drain connected to the primary absorption circuit of the flyback basic topology. Zener diodes ZD1 and ZD2 are used for voltage regulation control. ZD1 is connected between the gate of Q1 and ground, and ZD2 is connected between the DC input terminal and ground. An optocoupler, whose input is connected to the secondary output circuit and whose output is connected to the gate of Q1, is used to turn off Q1 and cut off the power supply to the primary startup resistor after the IC has stabilized. The primary absorption circuit of the basic flyback topology has its input terminal connected to the drain of the PMOS transistor and its output terminal connected to the main power voltage loop optocoupler control circuit to suppress voltage spikes during flyback switching. The main power voltage loop optocoupler control circuit has its input terminal connected to the output terminal of the primary absorption circuit of the flyback basic topology, and its output terminal connected to the main power current loop detection and control circuit and the IC_VCC winding power supply circuit, which is used to stabilize the output voltage. The main power current loop detection and control circuit has its input terminal connected to the output terminal of the main power voltage loop optocoupler control circuit, and its output terminal connected to the IC_VCC winding power supply circuit and the secondary multiple output circuit. It is used to detect the output current and adjust the working state. The IC_VCC winding power supply circuit has its input terminal connected to the output terminal of the main power voltage loop optocoupler control circuit and the main power current loop detection and control circuit, and its output terminal connected to the IC to provide a stable working power supply. The secondary multi-output circuit has its input terminal connected to the output terminal of the main power current loop detection and control circuit. It is used to provide multiple stable output voltages and control the power supply status of the PMOS transistors through feedback via an optocoupler.

2. The MPPT flyback auxiliary high-low voltage input power supply activation switching power supply circuit according to claim 1, characterized in that: The DC input terminal is connected to the MPPT solar panel or vehicle charging power supply to provide DC power, and provides initial power through current-limiting resistors R1-R6.

3. The MPPT flyback auxiliary high-low voltage input power supply activation switching power supply circuit according to claim 1, characterized in that: The start-up resistor is a 1206 surface mount resistor, with one end connected to the DC input terminal and the other end connected to the source of the PMOS transistor.

4. The MPPT flyback auxiliary source high / low voltage input power supply activation switching power supply circuit according to claim 1, characterized in that: The input terminal of the optocoupler is connected to the secondary multiple output circuit, and the output terminal is connected to the gate of the PMOS transistor. The drive signal is stabilized by a Zener diode to achieve automatic power supply switching.

5. The MPPT flyback auxiliary source high / low voltage input power supply activation switching power supply circuit according to claim 1, characterized in that: Automatic switching, isolation, and stable power supply of high and low voltage inputs are achieved through R7, R8, C1, ZD1, OP1, Q1, and D2. When the input voltage is 12V-60V, R1-R6 provide a stable power supply, and the PMOS transistor (Q1) is turned on; When the input voltage is 60V-150V, after the secondary multiple output circuit is working, OP1 is turned on, which turns off Q1 and disconnects R1-R6.

6. The MPPT flyback auxiliary high-low voltage input power supply activation switching power supply circuit according to claim 1, wherein: After the IC is activated and stabilized, the optocoupler receives a feedback signal from the secondary multiplex output circuit, which controls the Q1PMOS transistor to disconnect the power supply, so that R1-R6 stop continuously heating up.

7. The MPPT flyback auxiliary high-low voltage input power supply activation switching power supply circuit according to claim 1, wherein: The primary absorption circuit of the flyback basic topology includes: The transformer has its primary side connected to the drain of Q1 and its secondary side connected to the secondary multiple output circuit. Diodes are used for secondary rectification. Output capacitor, used to smooth the rectified output voltage.

8. The MPPT flyback auxiliary high-low voltage input power supply activation switching power supply circuit according to claim 1, wherein: The primary absorption circuit of the flyback basic topology absorbs high-frequency transient energy through the RCD clamping circuit, thereby reducing the voltage stress on the primary winding of the transformer.

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