Power supply circuit

Abstract

The utility model discloses a power supply circuit, which comprises an inductor L1, a main control chip U1, a driving chip U2, a sampling circuit and a switching circuit, and is characterized in that the input end of the sampling circuit is used for sampling an alternating current input signal to obtain a sampling signal; the output end of the sampling circuit is electrically connected with the input end of the main control chip U1 so as to feed back a sampling signal to the main control chip U1, and the output end of the main control chip U1 is electrically connected with the input end of the switching circuit so as to judge whether alternating current input exists or not according to the sampling signal, so that the on-off state of the switching circuit is controlled; the output end of the switching circuit is electrically connected with the power supply end of the driving chip U2 so as to control the working state of the driving chip U2, and the output end of the driving chip U2 is electrically connected with the inductor L1.

Description

Technical Field

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

[0002] The standby power of the existing drive power supply is high, and when the alternating current at the input end is switched on and off quickly and repeatedly, due to the untimely response of the drive circuit, the PFC inductor will be saturated, resulting in circuit damage. To solve this problem, usually, the method of increasing the inductor volume is adopted to ensure that it will not enter the saturation state, which will inevitably increase the volume of the power supply. Content of the Utility Model

[0003] The purpose of the utility model is to solve at least one of the technical problems existing in the prior art, and provide a power supply circuit that does not need to increase the inductor volume, can reduce the standby power, and avoid inductor saturation during repeated power on and off.

[0004] The power supply circuit according to an embodiment of the utility model includes an inductor L1, a main control chip U1, a drive chip U2, a sampling circuit, and a switching circuit. The input end of the sampling circuit is used to sample an AC input signal to obtain a sampling signal. The output end of the sampling circuit is electrically connected to the input end of the main control chip U1 to feedback the sampling signal to the main control chip U1. The output end of the main control chip U1 is electrically connected to the input end of the switching circuit to judge whether there is an AC input according to the sampling signal, so as to control the on-off state of the switching circuit. The output end of the switching circuit is electrically connected to the power supply end of the drive chip U2 to control the working state of the drive chip U2. The output end of the drive chip U2 is electrically connected to the inductor L1.

[0005] According to some embodiments of the utility model, the sampling circuit includes a triode Q1 and a diode D1. The anode of the diode D1 inputs the AC input signal. The cathode of the diode D1 is electrically connected to the base of the triode Q1. The collector of the triode Q1 is electrically connected to the power supply end of the main control chip U1. The emitter of the triode Q1 is grounded.

[0006] According to some embodiments of the utility model, the sampling circuit further includes a resistor R1, a resistor R2, and a resistor R3. One end of the resistor R1 is electrically connected to the base of the triode Q1. The other end of the resistor R1 is grounded. One end of the resistor R2 is electrically connected to the collector of the triode Q1. The other end of the resistor R2 is electrically connected to the power supply end of the main control chip U1. One end of the resistor R3 is electrically connected to the cathode of the diode D1. The other end of the resistor R3 is electrically connected to the base of the triode Q1.

[0007] According to some embodiments of the utility model, it further includes a capacitor C1. One end of the capacitor C1 is electrically connected to the base of the triode Q1. The other end of the capacitor C1 is grounded.

[0008] According to some embodiments of the present utility model, the switching circuit includes a diode D2, a MOS transistor Q2, and a triode Q3. The gate of the MOS transistor Q2 is electrically connected to the output terminal of the main control chip U1. The drain of the MOS transistor Q2 is electrically connected to the base of the triode Q3. The source of the MOS transistor Q2 is grounded. The collector of the triode Q3 inputs a DC voltage. The emitter of the triode Q3 is electrically connected to the anode of the diode D2. The cathode of the diode D2 is electrically connected to the power supply terminal of the driving chip U2.

[0009] According to some embodiments of the present utility model, the switching circuit further includes a resistor R4, a resistor R5, and a resistor R6. One end of the resistor R4 is electrically connected to the drain of the MOS transistor Q2. The other end of the resistor R4 is respectively electrically connected to the base of the triode Q3 and one end of the resistor R5. The other end of the resistor R5 is electrically connected to the collector of the triode Q3. One end of the resistor R6 is electrically connected to the gate of the MOS transistor Q2. The other end of the resistor R6 is electrically connected to the source of the MOS transistor Q2.

[0010] According to some embodiments of the present utility model, the switching circuit includes a capacitor C2 and a capacitor C3. One end of the capacitor C2 is electrically connected to the gate of the MOS transistor Q2. The other end of the capacitor C2 is electrically connected to the source of the MOS transistor Q2. One end of the capacitor C3 is electrically connected to the power supply terminal of the driving chip U1. The other end of the capacitor C3 is grounded.

[0011] The power supply circuit according to the embodiments of the present utility model has at least the following beneficial effects: The sampling circuit samples the AC input signal to obtain a sampling signal and feeds the sampling signal back to the main control chip U1. The main control chip U1 can determine whether there is an AC input according to the sampling signal and send a control signal to the switching circuit to control the on-off of the switching circuit, so as to quickly control the turning on or off of the driving chip U1. When quickly turning on and off the machine repeatedly, since the switching circuit is directly electrically connected to the power supply terminal of the driving chip U1, the driving chip U1 can be turned off or on in time, thereby preventing the inductor L1 from entering the saturation state and reducing the standby power at the same time.

[0012] The additional aspects and advantages of the present utility model will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The following further describes the specific embodiments of the present utility model with reference to the drawings;

[0014] Figure 1 is the schematic diagram of the power supply circuit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0015] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the drawings. The function of the drawings is to supplement the description in the text part of the specification, enabling people to intuitively and vividly understand each technical feature and the overall technical solution of the present invention. However, it should not be construed as a limitation on the protection scope of the present invention.

[0016] In the description of the present invention, it should be understood that for the orientation description, such as the orientation or positional relationship indicated by up, down, front, back, left, right, etc., is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the present invention.

[0017] In the description of the present invention, the meaning of "several" is one or more, the meaning of "multiple" is two or more. Understandings such as greater than, less than, exceeding, etc. do not include the recited number, and understandings such as above, below, within, etc. include the recited number. If there is a description of first and second, it is only for the purpose of distinguishing technical features and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or the sequence relationship of the indicated technical features.

[0018] Refer to Figure 1 , a power supply circuit of the present invention includes an inductor L1, a main control chip U1, a driving chip U2, a sampling circuit 20, and a switching circuit 20. The input end of the sampling circuit 20 is used to sample an AC input signal to obtain a sampling signal. The output end of the sampling circuit 20 is electrically connected to the input end of the main control chip U1 to feedback the sampling signal to the main control chip U1. The output end of the main control chip U1 is electrically connected to the input end of the switching circuit 20 to determine whether there is an AC input according to the sampling signal, thereby controlling the on-off state of the switching circuit 20. The output end of the switching circuit 20 is electrically connected to the power supply end of the driving chip U2 to control the working state of the driving chip U2. The output end of the driving chip U2 is electrically connected to the inductor L1. The sampling circuit 20 samples the AC input signal to obtain a sampling signal and feeds the sampling signal back to the main control chip U1. The main control chip U1 can determine whether there is an AC input according to the sampling signal and send a control signal to the switching circuit 20 to control the on-off of the switching circuit 20, thereby quickly controlling the turning on or off of the driving chip U1; when quickly and repeatedly turning on and off the machine, since the switching circuit 20 is directly electrically connected to the power supply end of the driving chip U1, it can timely turn off or turn on the driving chip U1, thereby preventing the inductor L1 from entering the saturation state and reducing the standby power at the same time.

[0019] Such as Figure 1, the sampling circuit 20 includes a triode Q1, a diode D1, a capacitor C1, a resistor R1, a resistor R2, and a resistor R3. The anode of the diode D1 inputs the AC input signal, the cathode of the diode D1 is electrically connected to the base of the triode Q1, the collector of the triode Q1 is electrically connected to the power supply terminal of the main control chip U1, and the emitter of the triode Q1 is grounded. One end of the resistor R1 is electrically connected to the base of the triode Q1, the other end of the resistor R1 is grounded, one end of the resistor R2 is electrically connected to the collector of the triode Q1, the other end of the resistor R2 is electrically connected to the power supply terminal of the main control chip U1, one end of the resistor R3 is electrically connected to the cathode of the diode D1, the other end of the resistor R3 is electrically connected to the base of the triode Q1, one end of the capacitor C1 is electrically connected to the base of the triode Q1, and the other end of the capacitor C1 is grounded. The diode D1 has a voltage stabilizing function, and the AC input signal is sampled and transmitted to the main control chip U1 through the on-off of the triode Q1. The structure is simple and easy to implement.

[0020] In some embodiments, the switching circuit 20 includes a diode D2, a MOS transistor Q2, a triode Q3, a resistor R4, a resistor R5, and a resistor R6. The gate of the MOS transistor Q2 is electrically connected to the output terminal of the main control chip U1, the drain of the MOS transistor Q2 is electrically connected to the base of the triode Q3, the source of the MOS transistor Q2 is grounded, the collector of the triode Q3 inputs a DC voltage, the emitter of the triode Q3 is electrically connected to the anode of the diode D2, and the cathode of the diode D2 is electrically connected to the power supply terminal of the driving chip U2. One end of the resistor R4 is electrically connected to the drain of the MOS transistor Q2, the other end of the resistor R4 is respectively electrically connected to the base of the triode Q3 and one end of the resistor R5, the other end of the resistor R5 is electrically connected to the collector of the triode Q3, one end of the resistor R6 is electrically connected to the gate of the MOS transistor Q2, and the other end of the resistor R5 is electrically connected to the source of the MOS transistor Q2. The MOS transistor Q2 has high precision and efficiency, enabling the switching circuit 20 to respond quickly.

[0021] Furthermore, the switching circuit 20 further includes a capacitor C2 and a capacitor C3. One end of the capacitor C2 is electrically connected to the gate of the MOS transistor Q2, the other end of the capacitor C2 is electrically connected to the source of the MOS transistor Q2, one end of the capacitor C3 is electrically connected to the power supply terminal of the driving chip U1, and the other end of the capacitor C3 is grounded. The capacitor C2 and the capacitor C3 have a voltage stabilizing function, improving the reliability of the circuit.

[0022] It is easy for those skilled in the art to understand that, on the premise of no conflict, the above preferred methods can be freely combined and superimposed.

[0023] The above are only the preferred embodiments of the present utility model, and do not limit the patent scope of the present utility model accordingly. Any equivalent structural transformation made under the inventive concept of the present utility model by using the content of the specification and drawings of the present utility model, or directly or indirectly applied to other related technical fields, shall be included within the patent protection scope of the present utility model.

Claims

1. A power supply circuit, characterized in that, Comprising: An inductor L1, a main control chip U1, a drive chip U2, a sampling circuit (10) and a switching circuit (20). The input end of the sampling circuit (10) is used to sample an AC input signal to obtain a sampling signal. The output end of the sampling circuit (10) is electrically connected to the input end of the main control chip U1 to feed back the sampling signal to the main control chip U1. The output end of the main control chip U1 is electrically connected to the input end of the switching circuit (20) to determine whether there is an AC input according to the sampling signal, thereby controlling the on / off state of the switching circuit (20). The output end of the switching circuit (20) is electrically connected to the power supply end of the drive chip U2 to control the working state of the drive chip U2. The output end of the drive chip U2 is electrically connected to the inductor L1.

2. The power supply circuit according to claim 1, wherein: The sampling circuit (10) includes a triode Q1 and a diode D1. The anode of the diode D1 inputs the AC input signal. The cathode of the diode D1 is electrically connected to the base of the triode Q1. The collector of the triode Q1 is electrically connected to the power supply end of the main control chip U1. The emitter of the triode Q1 is grounded.

3. The power supply circuit according to claim 2, wherein: The sampling circuit (10) further includes a resistor R1, a resistor R2 and a resistor R3. One end of the resistor R1 is electrically connected to the base of the triode Q1. The other end of the resistor R1 is grounded. One end of the resistor R2 is electrically connected to the collector of the triode Q1. The other end of the resistor R2 is electrically connected to the power supply end of the main control chip U1. One end of the resistor R3 is electrically connected to the cathode of the diode D1. The other end of the resistor R3 is electrically connected to the base of the triode Q1.

4. The power supply circuit according to claim 3, wherein: It further includes a capacitor C1. One end of the capacitor C1 is electrically connected to the base of the triode Q1. The other end of the capacitor C1 is grounded.

5. The power supply circuit according to claim 1, wherein: The switching circuit (20) includes a diode D2, a MOS transistor Q2 and a triode Q3. The gate of the MOS transistor Q2 is electrically connected to the output end of the main control chip U1. The drain of the MOS transistor Q2 is electrically connected to the base of the triode Q3. The source of the MOS transistor Q2 is grounded. The collector of the triode Q3 inputs a DC voltage. The emitter of the triode Q3 is electrically connected to the anode of the diode D2. The cathode of the diode D2 is electrically connected to the power supply end of the drive chip U2.

6. The power supply circuit according to claim 5, wherein: The switching circuit (20) further includes a resistor R4, a resistor R5 and a resistor R6. One end of the resistor R4 is electrically connected to the drain of the MOS transistor Q2. The other end of the resistor R4 is respectively electrically connected to the base of the triode Q3 and one end of the resistor R5. The other end of the resistor R5 is electrically connected to the collector of the triode Q3. One end of the resistor R6 is electrically connected to the gate of the MOS transistor Q2. The other end of the resistor R5 is electrically connected to the source of the MOS transistor Q2.

7. The power supply circuit according to claim 6, wherein: The switching circuit (20) includes a capacitor C2 and a capacitor C3. One end of the capacitor C2 is electrically connected to the gate of the MOS transistor Q2. The other end of the capacitor C2 is electrically connected to the source of the MOS transistor Q2. One end of the capacitor C3 is electrically connected to the power supply end of the drive chip U1. The other end of the capacitor C3 is grounded.

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