Switching power supply output circuit

Abstract

The utility model relates to the technical field of switching power supply circuits, in particular to a switching power supply output circuit. Comprising a QT1 triode, a WD1 voltage stabilizing diode, an R9 power supply resistor and a CVCC1 filter capacitor; the output circuit for outputting overvoltage and undervoltage signals is integrated with an IC2 window voltage comparator and is provided with R7, R8 and R10 as input resistors; the current sharing control circuit is used for realizing current sharing; and the output current limiting circuit is composed of an IC3 current amplifier and RC filters of an R12 and a C54. According to the utility model, the output current-limiting circuit is integrated, so that the switching power supply output circuit can effectively cope with instant large current or impact load, direct power failure or frequent restart caused by overpower is avoided, and the stability of a power supply module and the operation safety of the whole system are remarkably improved; and potential safety hazards caused by abnormal actions of control elements such as a relay are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of switching power supply circuits, in particular to a switching power supply output circuit. Background Art

[0002] In modern electronic devices and power supply systems, switching power supply modules play a vital role in effectively converting power to the required voltage and current specifications for use by various loads. However, existing switching power supply modules often expose several limitations when faced with diverse load conditions and complex application environments. In particular, most modules lack effective management of output current, especially current limiting functions, which results in direct power failure or frequent restart of the module due to overpower when encountering instantaneous high current demand or impact load, which not only affects the stable operation of the system, but may also cause abnormal operation of control components such as relays, thereby causing safety hazards. Utility Model Content

[0003] In order to solve the problems existing in the background technology, the utility model provides a switching power supply output circuit, comprising:

[0004] The power supply circuit, consisting of the QT1 transistor, the WD1 voltage-stabilizing diode, the R9 power supply resistor and the CVCC1 filter capacitor, provides linear regulated power supply for the rest of the circuits;

[0005] Output over-voltage and under-voltage signal output circuit, integrated IC2 window voltage comparator, set R7, R8, R10 as input resistors, R2 is the pull-up resistor at the comparator output end, ensure the output voltage is high level within the set range, and provide power for the external signal interface;

[0006] The current balancing control circuit uses the IC1 current amplifier, R5 and C42 to form an RC filter, amplify and filter the signal from the R6 current detection resistor, and send it to the switching power supply control terminal to adjust the output voltage and achieve current balancing;

[0007] The output current limiting circuit is composed of IC3 current amplifier, R12 and C54 RC filter. The signal is transmitted to the positive input terminal of IC4. R3 is the WD2 power supply resistor. R11 performs impedance matching and transmits it to the negative input terminal of IC4. R4 and C16 provide negative feedback. IC4 amplifies the signal and limits the current through R14 before transmitting it to the control terminal to realize the current limiting function.

[0008] The beneficial effects achieved by the utility model are:

[0009] First, the utility model integrates an output current limiting circuit so that the switching power supply output circuit can effectively cope with instantaneous large currents or impact loads, avoiding direct power outages or frequent restarts due to overpower, significantly improving the stability of the power module and the operating safety of the entire system, and reducing safety hazards caused by abnormal operations of control components such as relays.

[0010] Second, the designed current sharing control circuit enables the total output power to be increased by connecting multiple modules in parallel when the output power of a single module is insufficient, and ensures that the output power of each module is basically the same, greatly expanding the adaptability of the switching power supply to different load types and power requirements, and is particularly suitable for application scenarios that require high power output or dynamically changing loads.

[0011] Third, the output over-voltage and under-voltage signal output circuit can quickly send out an alarm signal when the output voltage of the switching power supply deviates from the normal range, and timely feedback the module output status, which helps the user or control system to quickly identify the problem and take corresponding measures, ensuring the stability and reliability of the output voltage, and is conducive to protecting the subsequent load equipment from the influence of voltage abnormalities.

[0012] Fourth, the integrated design of the circuit simplifies the overall architecture of the switching power supply, making design and debugging more convenient, while also facilitating subsequent maintenance and troubleshooting, reducing maintenance costs and the overall complexity of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the utility model. DETAILED DESCRIPTION

[0014] The technical solution of the utility model will be clearly and completely described below in conjunction with the drawings in the utility model. In addition, the forms of the various structures recorded in the following embodiments are merely illustrative, and the utility model is not limited to the various structures recorded in the following embodiments. All other implementations obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the utility model.

[0015] Reference Figure 1 A switching power supply output circuit is composed of four parts: a power supply circuit, an output over-voltage and under-voltage signal output circuit, a current sharing control circuit, and an output current limiting circuit.

[0016] The power supply circuit consists of QT1 transistor, WD1 voltage regulator diode, R9 is WD1 power supply resistor, CVCC1 is filter capacitor. These four devices form a linear voltage regulator circuit to power the rest of the circuit.

[0017] The output over-voltage and under-voltage signal output circuit consists of IC2 as the window voltage comparator, R7, R8, and R10 as the setting resistors for the IC2 window comparator input (switching power supply output voltage range), and R2 as the pull-up resistor at the comparator output. When the switching power supply output is within the range, its output is at a high level, and R2 provides power for other signal interfaces.

[0018] The current balancing control circuit consists of IC1 current amplifier, R5 and C42 forming an RC filter, which amplifies and filters the current signal generated by the R6 current detection resistor, and then sends it to the switching power supply control end, thereby controlling the switching power supply output voltage to achieve the purpose of current balancing.

[0019] The output current limiting circuit is composed of IC3 current amplifier, R12 and C54 form an RC filter, which sends the signal to the positive input terminal of IC4. R3 is the WD2 power supply resistor, and after impedance matching through R11, it is sent to the negative input terminal of IC4. R4 and C16 are negative feedback of IC4 AC signal. IC4 has infinite amplification factor. The amplified signal is limited by R14 and also sent to the control terminal of the switching power supply to achieve the purpose of current limiting of the switching power supply.

[0020] The switching power supply output circuit of the utility model is suitable for any switching power supply module. Combined with the actual working conditions and requirements of the user's load, a current limiting circuit is designed to match various loads. The purpose of current limiting is to limit the large current generated by the load so that the power is limited within a safe range. The output voltage of the switching power supply fluctuates slightly, so that the equipment will not be powered off, because when the power is off, the abnormal operation of switches such as relays is easy to cause safety accidents. Since most modules do not have current limiting characteristics, but only hiccup characteristics, they will be powered off when the power is exceeded. This characteristic cannot carry some impact loads well, and the module can easily cause overload restart. When the output voltage is not within the normal range, the signal is sent out in time, and the output status of the module is reported in time. After adding the current sharing control circuit, when the output power of a single module is insufficient, two modules with smaller capacity can be connected in parallel (N modules can be connected in parallel) to form a high-power module, and the output power of each module is basically the same.

[0021] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A switching power supply output circuit, characterized in that: include: The power supply circuit, consisting of the QT1 transistor, the WD1 voltage-stabilizing diode, the R9 power supply resistor and the CVCC1 filter capacitor, provides linear regulated power supply for the rest of the circuits; Output over-voltage and under-voltage signal output circuit, integrated IC2 window voltage comparator, set R7, R8, R10 as input resistors, R2 is the pull-up resistor at the comparator output end, ensure the output voltage is high level within the set range, and provide power for the external signal interface; The current balancing control circuit uses the IC1 current amplifier, R5 and C42 to form an RC filter, amplify and filter the signal from the R6 current detection resistor, and send it to the switching power supply control terminal to adjust the output voltage and achieve current balancing; The output current limiting circuit is composed of IC3 current amplifier, R12 and C54 RC filter. The signal is transmitted to the positive input terminal of IC4. R3 is the WD2 power supply resistor. R11 performs impedance matching and transmits it to the negative input terminal of IC4. R4 and C16 provide negative feedback. IC4 amplifies the signal and passes through R14 to limit the current before reaching the control terminal to achieve current limiting.

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