Switching power supply circuit

Abstract

The utility model discloses a switching power supply circuit which comprises a rectifying unit, a voltage transformation unit, a power supply management unit, a first overcurrent protection unit and a voltage reduction unit. The input end of the rectification unit is used for inputting AC signals. The positive output end of the rectification unit is connected with the first input end of the voltage transformation unit. The second input end of the voltage transformation unit is connected with the input end of the power management unit, and the output end of the power management unit is connected with the negative output end of the rectification unit. The first end of the first overcurrent protection unit is connected with the first output end of the voltage transformation unit. The input end of the voltage reduction unit is connected with the second end of the first overcurrent protection unit. The output end of the step-down unit is used for outputting target electric signals.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of switching power supply, in particular to a switching power supply circuit. BACKGROUND

[0002] With the improvement of electrification, the number of household and industrial electrical equipment increases significantly, and the electrical safety hazards also increase. Among them, the switching power supply equipment has the risk of overcurrent, which may cause damage to electrical equipment, electromagnetic interference, electrical fire and other serious consequences, and the safety is not high. CONTENT OF THE UTILITY MODEL

[0003] The present application aims to provide a switching power supply circuit which can solve the problem of overcurrent of traditional switching power supply equipment.

[0004] The present application provides a switching power supply circuit, comprising:

[0005] A rectifier unit, an input end of the rectifier unit is used for inputting an alternating current signal;

[0006] A transformer unit, a positive output end of the rectifier unit is connected to a first input end of the transformer unit;

[0007] A power management unit, a second input end of the transformer unit is connected to an input end of the power management unit, and an output end of the power management unit is connected to a negative output end of the rectifier unit;

[0008] A first overcurrent protection unit, a first end of the first overcurrent protection unit is connected to a first output end of the transformer unit;

[0009] A step-down unit, an input end of the step-down unit is connected to a second end of the first overcurrent protection unit, and an output end of the step-down unit is used for outputting a target electrical signal.

[0010] According to some embodiments of the present application, further comprising:

[0011] A voltage stabilizing unit, a first output end of the transformer unit is connected to an input end of the voltage stabilizing unit, and an output end of the voltage stabilizing unit is connected to an input end of the step-down unit.

[0012] According to some embodiments of the present application, the power management unit comprises:

[0013] A power management chip, an input end of the power management chip is connected to the second input end of the transformer unit, and an output end of the power management chip is connected to the negative output end of the rectifier unit;

[0014] A photocoupler, a first output end of the photocoupler is connected to a bypass end of the power management chip, a second output end of the photocoupler is connected to a feedback end of the power management chip, a first input end of the photocoupler is connected to a second end of the first overcurrent protection unit, and a second input end of the photocoupler is connected to an input end of the voltage stabilizing unit.

[0015] According to some embodiments of the present application, further comprising:

[0016] A first diode, an anode of the first diode is connected to a first input end of the voltage conversion unit.

[0017] A second diode, a cathode of the second diode is connected to a cathode of the first diode, and an anode of the second diode is connected to an input end of the power management unit.

[0018] According to some embodiments of the present application, further comprising:

[0019] A first capacitor, a first end of the first capacitor is connected to a first input end of the voltage conversion unit, and a second end of the first capacitor is grounded.

[0020] According to some embodiments of the present application, further comprising:

[0021] A third diode, an anode of the third diode is connected to a second end of the first overcurrent protection unit, and a cathode of the third diode is connected to an input end of the voltage reduction unit.

[0022] According to some embodiments of the present application, further comprising:

[0023] A first resistor, a first end of the first resistor is connected to an anode of the third diode.

[0024] A second capacitor, a second end of the first resistor is connected to a first end of the second capacitor, and a second end of the second capacitor is connected to a cathode of the third diode.

[0025] According to some embodiments of the present application, further comprising:

[0026] A fourth diode, a cathode of the fourth diode is connected to an input end of the voltage reduction unit, and an anode of the fourth diode is grounded.

[0027] According to some embodiments of the present application, the voltage reduction unit comprises:

[0028] A voltage reduction chip, an input end of the voltage reduction chip is connected to a second end of the first overcurrent protection unit.

[0029] An inductor, a first end of the inductor is connected to an output end of the voltage reduction chip, and a second end of the inductor is used for outputting the target electrical signal.

[0030] According to some embodiments of the present application, the voltage reduction unit further comprises:

[0031] A second overcurrent protection unit, a first end of the second overcurrent protection unit is connected to a second end of the first overcurrent protection unit, and a second end of the second overcurrent protection unit is connected to an input end of the voltage reduction chip.

[0032] In the embodiments of the present application, the alternating current signal is rectified into a first direct current signal by the rectification unit, and the voltage conversion unit converts the voltage of the first direct current signal, so that the first output end of the voltage conversion unit outputs a second direct current signal of a preset size. The voltage reduction unit further reduces the voltage of the second direct current signal, thereby outputting a target electric signal of a preset size, and the power management unit stabilizes the voltage in the circuit. Since the first overcurrent protection unit is arranged between the voltage conversion unit and the voltage reduction unit, when an overcurrent fault occurs in the circuit, the first overcurrent protection unit is triggered to work, thereby protecting the circuit and improving safety.

[0033] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0034] The present application will be further described below in conjunction with the accompanying drawings and embodiments, in which:

[0035] Figure 1 A circuit diagram of an embodiment of the switching power supply circuit provided by the present application;

[0036] Figure 2 A circuit diagram of the voltage reduction unit in an embodiment of the switching power supply circuit provided by the present application. DETAILED DESCRIPTION

[0037] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the accompanying drawings, in which the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0038] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, etc. is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0039] In the description of the present application, more refers to more than two. If there is a description of the first, the second is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.

[0040] In the description of the present application, unless otherwise explicitly limited, the words such as setting, installation, connection and the like should be broadly understood, and those skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical scheme.

[0041] The following refers to Figures 1 to 2 A switching power supply circuit according to an embodiment of the present application is described.

[0042] An embodiment of the present application provides a switching power supply circuit, as shown in Figure 1 The switching power supply circuit comprises:

[0043] A rectifier unit D3, an input end of the rectifier unit D3 is used for inputting an alternating current signal;

[0044] A transformer unit T1, a positive output end of the rectifier unit D3 is connected to a first input end T1_1 of the transformer unit T1;

[0045] A power management unit, a second input end T1_4 of the transformer unit T1 is connected to an input end of the power management unit, and an output end of the power management unit is connected to a negative output end of the rectifier unit D3;

[0046] A first overcurrent protection unit F1, a first end of the first overcurrent protection unit F1 is connected to a first output end T1_6 of the transformer unit T1;

[0047] A step-down unit, an input end of the step-down unit is connected to a second end of the first overcurrent protection unit F1, and an output end of the step-down unit is used for outputting a target electric signal.

[0048] In the embodiment of the present application, the alternating current signal is rectified into a first direct current signal by the rectifier unit D3, the transformer unit T1 performs voltage conversion on the first direct current signal, so that the first output end T1_6 of the transformer unit T1 outputs a second direct current signal of a preset size, and the step-down unit further steps down the second direct current signal, thereby outputting a target electric signal of a preset size. The power management unit stabilizes the voltage in the circuit. Since the first overcurrent protection unit F1 is arranged between the transformer unit T1 and the step-down unit, when an overcurrent fault occurs in the circuit, the first overcurrent protection unit F1 is triggered to work, thereby protecting the circuit and improving safety.

[0049] In some embodiments of the present application, the second output end of the voltage transformation unit T1 is grounded, the current in the voltage transformation unit T1 flows from the first input end T1_1 to the second input end T1_4, and flows from the first output end T1_6 to the second output end.

[0050] In some embodiments of the present application, the first overcurrent protection unit F1 can adopt a device with overcurrent protection function, for example, a fuse, a current limiting protector, a self-resetting fuse, etc. The fuse is fused to cut off the current after the current abnormally rises to a certain degree and for a certain time, thereby playing a role in protecting the safe operation of the circuit. The current limiting protector realizes fast current limiting protection when a short circuit fault occurs in the circuit, reducing the heat accumulation and eliminating the fault arc caused by overcurrent. The self-resetting fuse rapidly disconnects the circuit when an overcurrent or short circuit fault occurs, preventing the current from flowing. Once the fault is removed, the self-resetting fuse can automatically restore the conduction state, allowing the current to flow again. The rectification unit D3 can adopt a rectification bridge module with a model number of MB10S. The voltage transformation unit T1 can adopt a vertical high-frequency transformer.

[0051] In some embodiments of the present application, as shown in Figure 1 , further comprising:

[0052] The voltage stabilization unit U6 has its input end connected to the first output end T1_6 of the voltage transformation unit T1, and its output end connected to the input end of the voltage reduction unit.

[0053] In the present embodiment, the voltage stabilization unit U6 can stabilize the output voltage of the circuit. The voltage stabilization unit U6 can adopt a voltage stabilization chip with a model number of TL431A-SOT23.

[0054] In some embodiments of the present application, as shown in Figure 1 , the output end of the voltage stabilization unit U6 is connected to the input end of the voltage reduction unit through a second resistor R29, and the output end of the voltage stabilization unit U6 is grounded through a third resistor R30.

[0055] In the present embodiment, by setting the resistance values of the second resistor R29 and the third resistor R30, the voltage input to the input end of the voltage reduction unit can be determined.

[0056] In some embodiments of the present application, as shown in Figure 1 , the power management unit comprises:

[0057] The power management chip U4 has its input end connected to the second input end T1_4 of the voltage transformation unit T1, and its output end connected to the negative output end of the rectification unit D3.

[0058] The first output end of the optocoupler U5 is connected to the bypass end of the power management chip U4, the second output end of the optocoupler U5 is connected to the feedback end of the power management chip U4, the first input end of the optocoupler U5 is connected to the second end of the first overcurrent protection unit F1, and the second input end of the optocoupler U5 is connected to the input end of the voltage stabilizing unit U6.

[0059] In the embodiment, the second input end T1_4 of the voltage transformation unit T1 supplies power to the first input end of the optocoupler U5, so that the light emitter in the optocoupler U5 works, the light receiver in the optocoupler U5 receives light to generate current, and the power management chip U4 can control the output voltage of the circuit to realize isolation control.

[0060] In some embodiments of the present application, as shown in Figure 1 , further comprising:

[0061] The anode of the first diode D2 is connected to the first input end T1_1 of the voltage transformation unit T1.

[0062] The cathode of the second diode D4 is connected to the cathode of the first diode D2, and the anode of the second diode D4 is connected to the input end of the power management unit.

[0063] In the embodiment, the first diode D2 is a TVS diode, which can play a rectifying role. The second diode D4 is a reverse recovery diode, which can improve the response speed and efficiency of the power management chip U4.

[0064] In some embodiments of the present application, as shown in Figure 1 , further comprising:

[0065] The first end of the first capacitor C16 is connected to the first input end T1_1 of the voltage transformation unit T1, and the second end of the first capacitor C16 is grounded.

[0066] In the embodiment, the first capacitor C16 plays a filtering role.

[0067] In some embodiments of the present application, as shown in Figure 1 , further comprising:

[0068] The anode of the third diode D1 is connected to the second end of the first overcurrent protection unit F1, and the cathode of the third diode D1 is connected to the input end of the voltage reduction unit.

[0069] In the embodiment, the third diode D1 is a Schottky diode, which can prevent reverse current from flowing through and protect the components in the circuit.

[0070] In some embodiments of the present application, as shown in Figure 1 , further comprising:

[0071] a first resistor R25, a first end of the first resistor R25 being connected to an anode of the third diode D1;

[0072] a second capacitor C11, a second end of the first resistor R25 being connected to a first end of the second capacitor C11, a second end of the second capacitor C11 being connected to a cathode of the third diode D1.

[0073] In the embodiment, the first resistor R25 and the second capacitor C11 constitute an RC circuit, which can reduce impedance of a high-frequency signal, improve response speed, and filter.

[0074] In some embodiments of the present application, as shown in FIG. 1, the first resistor R25 and the second capacitor C11 further comprise: Figure 1

[0075] a third capacitor C12, one end of the third capacitor C12 being connected to the cathode of the third diode D1, the other end of the third capacitor C12 being grounded;

[0076] a fourth capacitor C14, one end of the fourth capacitor C14 being connected to the cathode of the third diode D1, the other end of the fourth capacitor C14 being grounded.

[0077] In the embodiment, the third capacitor C12 and the fourth capacitor C14 filter.

[0078] In some embodiments of the present application, as shown in FIG. 1, the first resistor R25 and the second capacitor C11 further comprise: Figure 1

[0079] a fourth diode D5, a cathode of the fourth diode D5 being connected to an input end of the voltage reduction unit, an anode of the fourth diode D5 being grounded.

[0080] In the embodiment, the fourth diode D5 is a Schottky diode, which prevents reverse connection of the circuit.

[0081] In some embodiments of the present application, as shown in FIG. 1, the voltage reduction unit comprises: Figure 1

[0082] a voltage reduction chip U2, an input end of the voltage reduction chip U2 being connected to a second end of the first overcurrent protection unit F1;

[0083] an inductor L1, a first end of the inductor L1 being connected to an output end of the voltage reduction chip U2, a second end of the inductor L1 being used for outputting a target electrical signal.

[0084] ​​​In the embodiment, the second end of the first overcurrent protection unit F1 is connected to the second interface P1 through the first interface P2, the second interface P1 is connected to the input end of the voltage reduction chip U2, the voltage reduction chip U2 is used to reduce the second direct current signal output by the first output end T1_6 of the voltage transformation unit T1, and then output a target electric signal of a preset size through the inductor L1. The inductor L1 can stabilize the current and reduce the ripple. The voltage reduction chip U2 can be a synchronous voltage reduction stabilizer with a model number of SY8120I.

[0085] In some embodiments of the present application, as shown in Figure 2 The voltage reduction unit further comprises:

[0086] The second overcurrent protection unit F2 has a first end connected to the second end of the first overcurrent protection unit F1 and a second end connected to the input end of the voltage reduction chip U2.

[0087] In the embodiment, the second overcurrent protection unit F2 is used to protect the circuit from overcurrent.

[0088] In some embodiments of the present application, the second overcurrent protection unit F2 can be a device with an overcurrent protection function, such as a fuse, a current limiting protector, a self-resetting fuse, etc. The fuse is fused to cut off the current when the current abnormally rises to a certain degree and for a certain time, thereby protecting the safe operation of the circuit. The current limiting protector realizes rapid current limiting protection when a short circuit fault occurs in the circuit, reducing the heat accumulation and eliminating the fault arc caused by overcurrent. The self-resetting fuse rapidly disconnects the circuit when an overcurrent or short circuit fault occurs, preventing the current from flowing. Once the fault is removed, the self-resetting fuse can automatically restore the conduction state, allowing the current to flow again.

[0089] In some embodiments of the present application, as shown in Figure 2 The voltage reduction unit further comprises:

[0090] The fifth diode D6 has an anode connected to the ground and a cathode connected to the input end of the voltage reduction chip U2.

[0091] In the embodiment, the fifth diode D6 is a Schottky diode, which prevents reverse connection of the circuit.

[0092] In some embodiments of the present application, as shown in Figure 2 The voltage reduction unit further comprises:

[0093] The fifth capacitor C9 has a first end connected to the input end of the voltage reduction chip U2 and a second end connected to the ground.

[0094] The sixth capacitor C10 has a first end connected to an input end of the voltage reduction chip U2, and a second end grounded.

[0095] In the embodiment, the fifth capacitor C9 and the sixth capacitor C10 are used for filtering, so as to stabilize the input of the voltage reduction chip U2.

[0096] In some embodiments of the present application, as shown in Figure 2 the voltage reduction unit further comprises:

[0097] The fourth resistor R6 has a first end connected to the second end of the inductor L1.

[0098] The fifth resistor R7 has a first end connected to the second end of the fourth resistor R6, and a second end grounded.

[0099] In the embodiment, the fourth resistor R6 and the fifth resistor R7 constitute a feedback resistor voltage divider, and the voltage of the target electrical signal output by the inductor L1 can be changed by changing the resistance values of the fourth resistor R6 and the fifth resistor R7.

[0100] In some embodiments of the present application, as shown in Figure 2 the voltage reduction chip U2 has a seventh capacitor C4 connected between an output end and a BS end, an eighth capacitor C5 connected between the second end of the inductor L1 and a feedback end of the voltage reduction chip U2, and the second end of the inductor L1 is grounded through a ninth capacitor C6, a tenth capacitor C7 and an eleventh capacitor C2.

[0101] In the embodiment, the seventh capacitor C4, the eighth capacitor C5, the ninth capacitor C6 and the tenth capacitor C7 all serve to reduce noise, and the eleventh capacitor C2 serves to reduce noise and ripple.

[0102] In some embodiments of the present application, as shown in Figure 2 Figure 2 the second end of the inductor L1 is grounded through a sixth resistor R5 and a twelfth capacitor C3 in sequence.

[0103] In the embodiment, the sixth resistor R5 is used for limiting loop backflow, and the twelfth capacitor C3 is used for reducing noise and ripple.

[0104] The embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the present application.

Claims

1. A switching power supply circuit, characterized by comprising: Comprising: a rectifier unit, an input end of the rectifier unit being used for inputting an alternating current signal; a transformer unit, a positive output end of the rectifier unit being connected to a first input end of the transformer unit; a power management unit, a second input end of the transformer unit being connected to an input end of the power management unit, an output end of the power management unit being connected to a negative output end of the rectifier unit; a first overcurrent protection unit, a first end of the first overcurrent protection unit being connected to a first output end of the transformer unit; a step-down unit, an input end of the step-down unit being connected to a second end of the first overcurrent protection unit, an output end of the step-down unit being used for outputting a target electric signal.

2. The switching power supply circuit according to claim 1, characterized by Further comprising: a voltage stabilizing unit, a first output end of the transformer unit being connected to an input end of the voltage stabilizing unit, an output end of the voltage stabilizing unit being connected to an input end of the step-down unit.

3. The switching power supply circuit according to claim 2, characterized in that, The power management unit comprises: a power management chip, an input end of the power management chip being connected to the second input end of the transformer unit, an output end of the power management chip being connected to the negative output end of the rectifier unit; an optocoupler, a first output end of the optocoupler being connected to a bypass end of the power management chip, a second output end of the optocoupler being connected to a feedback end of the power management chip, a first input end of the optocoupler being connected to the second end of the first overcurrent protection unit, a second input end of the optocoupler being connected to the input end of the voltage stabilizing unit.

4. The switching power supply circuit according to claim 1, characterized by Further comprising: a first diode, an anode of the first diode being connected to the first input end of the transformer unit; a second diode, a cathode of the second diode being connected to a cathode of the first diode, an anode of the second diode being connected to the input end of the power management unit.

5. The switching power supply circuit according to claim 1, characterized by Further comprising: a first capacitor, a first end of the first capacitor being connected to the first input end of the transformer unit, a second end of the first capacitor being grounded.

6. The switching power supply circuit according to claim 1, characterized by Further comprising: a third diode, an anode of the third diode being connected to the second end of the first overcurrent protection unit, a cathode of the third diode being connected to the input end of the step-down unit.

7. The switching power supply circuit according to claim 6, characterized in that Further comprising: a first resistor, a first end of the first resistor being connected to the anode of the third diode; a second capacitor, a second end of the first resistor being connected to a first end of the second capacitor, a second end of the second capacitor being connected to the cathode of the third diode.

8. The switching power supply circuit according to claim 1, characterized by Further comprising: a fourth diode, a cathode of the fourth diode being connected to the input end of the step-down unit, an anode of the fourth diode being grounded.

9. The switching power supply circuit according to claim 1, characterized by The step-down unit comprises: a step-down chip, an input end of the step-down chip being connected to the second end of the first overcurrent protection unit; an inductor, a first end of the inductor being connected to an output end of the step-down chip, a second end of the inductor being used for outputting the target electric signal.

10. The switching power supply circuit according to claim 9, characterized in that, The step-down unit further comprises: a second overcurrent protection unit, a first end of the second overcurrent protection unit being connected to the second end of the first overcurrent protection unit, a second end of the second overcurrent protection unit being connected to the input end of the step-down chip.

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