Control circuit capable of improving energy efficiency of power supply and switching power supply

Abstract

The utility model relates to the related technical field of switching power supplies, and provides a control circuit capable of improving the energy efficiency of a power supply and a switching power supply, comprising a relay K1 and a relay control circuit, the relay control circuit comprises a photoelectric coupler U4, a triode QP1 and a triode QP2 which are connected in sequence, the conduction of the photoelectric coupler U4 controls the conduction of the triode QP2, the conduction of the triode QP2 controls the conduction of the triode QP1, the triode QP1 is connected with a coil terminal of the relay K1, and the on-off control of a coil of the relay K1 is realized; the primary side of the photoelectric coupler U4 is connected to the first feedback end of the to-be-controlled circuit, and the secondary side of the photoelectric coupler U4 is connected to the second feedback end of the to-be-controlled circuit. The control circuit is designed to cut off the thermistor after the power supply is started, so that the energy consumption of the switching circuit can be greatly reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of switching power supplies, and in particular to a control circuit and a switching power supply capable of improving power supply energy efficiency. Background Art

[0002] The statements in this section merely provide background technical information related to the present invention and do not necessarily constitute prior art.

[0003] With the continuous development of Internet of Things technology and mobile electronic devices, consumer electronic products are used more and more frequently, and their power consumption is also faster. The demand for matching switching power supplies is gradually expanding. At present, energy conservation and environmental protection are advocated for electrical or electronic products. The energy efficiency of switching power supplies has been upgraded from the previous level 1 to the current level 5 or 6, and the energy efficiency standard will be raised to level 7, which greatly increases the design difficulty of switching power supplies.

[0004] During their research, the inventors discovered that many existing switching power supply designs use thermistors as surge protection devices. During startup, thermistors effectively limit inrush current and protect other components in the circuit. However, even after the circuit is started, the thermistor remains in operation, resulting in continuous energy loss. This continuous operation not only increases the overall energy consumption of the circuit, but also, due to the rising operating temperature of the thermistor, may trigger additional heat dissipation requirements, further increasing system energy consumption. Utility Model Content

[0005] In order to solve the above problems, the present invention proposes a control circuit and a switching power supply that can improve the energy efficiency of the power supply. The control circuit is designed to short-circuit the thermistor after the power supply is started, which can greatly reduce the energy consumption of the switching circuit.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] One or more embodiments provide a control circuit capable of improving power supply energy efficiency, including a relay K1 and a relay control circuit; the relay control circuit includes a photocoupler U4, a transistor QP1, and a transistor QP2 connected in sequence; the photocoupler U4 turns on to control the transistor QP2, which in turn turns on to control the transistor QP1; the transistor QP1 is connected to the coil terminals of the relay K1 to implement on-off control of the coil of the relay K1;

[0008] The primary side of the photocoupler U4 is connected to the first feedback terminal of the circuit to be controlled, and the secondary side of the photocoupler U4 is connected to the second feedback terminal of the circuit to be controlled.

[0009] One or more embodiments provide a switching power supply, which adopts the above-mentioned control circuit capable of improving power supply energy efficiency and is arranged at both ends of a device or circuit to be short-circuited in a switching power supply circuit.

[0010] Compared with the prior art, the beneficial effects of the present invention are:

[0011] The utility model is provided with a photoelectric coupler U4 and two transistors to control the on and off of the relay K1. The photoelectric coupler U4 is turned on after determining that both the first feedback end and the second feedback end of the circuit to be controlled have voltages. Therefore, after ensuring that both the first feedback end and the second feedback end can meet the conditions, control is performed through the relay control circuit, thereby improving the reliability of the operation of the circuit to be controlled.

[0012] The advantages of the present invention and additional advantages will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute a limitation of the present invention.

[0014] Figure 1 This is a switching power supply circuit diagram of Example 2 of the present utility model;

[0015] Figure 2 1 is a circuit diagram of an input circuit of Example 2 of the present utility model;

[0016] Figure 3 1 is a circuit diagram of a control circuit of Example 1 of the present utility model;

[0017] Figure 4 1 is a circuit diagram of a control module of Example 2 of the present utility model;

[0018] Figure 5 This is a circuit diagram of a rectifier and filter module according to Embodiment 2 of the present utility model;

[0019] Figure 6 This is a circuit diagram of the transformer module of Example 2 of the present utility model. DETAILED DESCRIPTION

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0022] It should be noted that the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof. It should be noted that, in the absence of conflict, the various embodiments of the present invention and the features in the embodiments can be combined with each other. The embodiments will be described in detail below with reference to the accompanying drawings.

[0023] In the technical solutions disclosed in one or more embodiments, Figure 1 and Figure 3 As shown, a control circuit capable of improving power supply energy efficiency is used to provide a short-circuit loop to achieve short-circuit control of a single device or part of the circuit devices in a circuit or system, including a relay K1 and a relay control circuit; the relay control circuit includes a photoelectric coupler U4, a transistor QP1, and a transistor QP2 connected in sequence, wherein the conduction of the photoelectric coupler U4 controls the conduction of the transistor QP2, which controls the conduction of the transistor QP1, and the transistor QP1 is connected to the coil terminal of the relay K1 to achieve on-off control of the coil of the relay K1;

[0024] The primary side of the photocoupler U4 is connected to the first feedback terminal of the circuit to be controlled, and the secondary side of the photocoupler U4 is connected to the second feedback terminal of the circuit to be controlled.

[0025] In this embodiment, a photoelectric coupler U4 and two transistors are provided to control the on and off of the relay K1. The photoelectric coupler U4 is turned on after determining that both the first feedback terminal and the second feedback terminal of the circuit to be controlled have voltages. Thus, after ensuring that both the first feedback terminal and the second feedback terminal meet the conditions, control is performed through the relay control circuit, thereby improving the reliability of the operation of the circuit to be controlled.

[0026] In some embodiments, the circuit to be controlled is a power circuit, the internal switch terminals of the relay K1 are connected to the thermistor NTC1 in the power circuit, and the coil terminals of the relay K1 are connected to the relay control circuit;

[0027] Specifically, in this embodiment, the switch terminal of the relay K1 is connected to the thermistor NTC1 of the power circuit, so as to short-circuit the thermistor NTC1 when the switching power supply is normally working after startup;

[0028] Optionally, the first feedback end and the second feedback end are respectively arranged at the front end and the back end of the circuit according to the specific control circuit setting and the order of the circuit operation; and are used to detect that the front end circuit and the back end circuit of the circuit to be controlled can meet the control conditions, and then perform relay control to achieve circuit control;

[0029] Specifically, in this embodiment, the circuit to be controlled is a power supply circuit, the first feedback end is at the primary side circuit of the transformer, and the second feedback end is at the output end of the power supply circuit.

[0030] Specifically, the first feedback end is the input circuit of the power supply circuit, and the input circuit provides a configuration voltage to the primary of the optocoupler U4 through the diode DC and the resistor RA3; the output end of the power supply circuit serves as the second feedback end and is grounded through the secondary of the optocoupler U4; when the power supply has an output, the secondary of the optocoupler U4 starts to conduct, and the primary of the optocoupler U4 also enters a saturated conduction state at the same time, that is, the optocoupler U4 is turned on.

[0031] It is feasible to set a first feedback circuit at the second feedback end, one end of the first feedback circuit is connected to the positive pole of the power supply output circuit, and the other end is grounded; the first feedback circuit includes a resistor RP11 and a secondary of the photocoupler U4 connected in series, and the two ends of the secondary of the photocoupler U4 are connected in parallel with a resistor RP12.

[0032] In some embodiments, the optocoupler U4 is turned on to control the transistor QP2 to be turned on, and the output end of the optocoupler U4 is connected to the base of the transistor QP2;

[0033] A further technical solution is provided with a fast on-off control circuit between the optocoupler U4 and the transistor QP2. The fast on-off control circuit includes a diode DP1 and a transistor QP3. The base of the transistor QP2 is connected to the cathode of the diode DP1. After the connection, the anode of the diode DP1 is connected to the primary terminal of the optocoupler U4; the emitter of the transistor QP3 is connected to the cathode of the diode DP1, so that the diode DP1 and the transistor QP3 form a closed loop.

[0034] In the above scheme, the above-mentioned fast on-off control circuit setting has two functions: one is fast conduction control, the diode DP1 can be quickly turned on after the optocoupler U4 is turned on, thereby further enabling the transistor QP2 to be quickly turned on, which can shorten the operation time of the relay K1; the second is to reduce power consumption while achieving fast on-off. The setting of the transistor QP3 can effectively reduce the temperature drift of the diode DP1 and achieve fast on-off, thereby reducing power consumption.

[0035] In one achievable implementation, the collector of the transistor QP2 is connected to one end of the primary connected to the first feedback end of the photoelectric coupler U4 through the resistor RP10 and the resistor RP5, and the emitter of the transistor QP2 is grounded;

[0036] Optionally, the base of the transistor QP2 is further connected to a voltage stabilizing filter circuit, including a resistor RP3 and a capacitor CP1 connected in parallel between the base of QP2 and ground, and a voltage stabilizing diode ZD6; the anode of the voltage stabilizing diode ZD6 is connected to the base of the transistor QP2, and the cathode of the voltage stabilizing diode ZD6 is connected to the cathode of the diode DP1 of the fast on-off control circuit;

[0037] In one achievable implementation, the transistor QP2 is turned on to control the transistor QP1 to be turned on, the collector of the transistor QP2 is connected to the base of the transistor QP1, and the emitter and collector of the transistor QP1 are respectively connected to one end of the primary of the photocoupler U4 connected to the first feedback end;

[0038] Specifically, the emitter of transistor QP1 is connected to the primary of optocoupler U4 through resistor RP4 and is grounded through capacitor CP2;

[0039] A further technical solution is that a voltage stabilizing filter current limiting circuit is further provided on the connection path between the transistor QP1 and the coil terminal of the relay K1, including current limiting resistors RP6 and RP7, a voltage stabilizing diode ZD5, a capacitor CP3, a voltage dividing resistor RP8, and a voltage dividing resistor RP9 connected in sequence; capacitor CP3 is connected across the voltage stabilizing diode ZD5; ​​the voltage stabilizing diode ZD5 is connected between the reference electrode R and the anode of the voltage stabilizing integrator U2 via the voltage dividing resistors RP8 and RP9, so that the voltage stabilizing integrator U2 is turned on under the action of the voltage difference, the coil terminal of the relay K1 is grounded, and the relay K1 is actuated to short-circuit the thermistor NTC1;

[0040] Capacitor CP3 is connected across the Zener diode to act as a filter, reducing voltage fluctuations and suppressing high-frequency noise, ensuring the purity and stability of the output voltage.

[0041] The voltage divider resistors RP8 and RP9 are used to provide a suitable voltage to act on the voltage regulator integrator U2 to protect circuit components from damage caused by excessive current, while also reducing the impact of current fluctuations on the circuit.

[0042] Furthermore, a freewheeling diode DB is provided at both ends of the relay coil terminal; the freewheeling diode DB is connected in parallel with the coil of the relay K1, the positive electrode of the freewheeling diode DB is connected to the negative end of the coil (terminal 2), and the negative electrode of the freewheeling diode DB is connected to the positive end of the coil (terminal 1);

[0043] The function of the freewheeling diode DB is to prevent the reverse electromotive force generated when the relay coil is powered off from damaging the circuit, and the freewheeling diode DB absorbs the reverse current;

[0044] Furthermore, the positive end (terminal 1) of the relay coil terminal is also connected to a current limiting resistor RA1 and a diode DA connected in series; the diode DA control circuit is unidirectionally conductive, and the function of RA1 is to limit the current passing through DA to prevent excessive current from passing through.

[0045] Specifically, the positive terminal (terminal 1) of the relay coil terminal is connected to the first feedback terminal of the circuit to be controlled, and for the power circuit, connected to the output terminal of the DC / DC conversion circuit of the power circuit.

[0046] like Figure 2 The working process of the relay control circuit shown is:

[0047] The input circuit in the switching power supply circuit provides the configuration voltage to the primary of the optocoupler U4 through the diode DC and the resistor RA3. When the switching power supply has an output voltage, the secondary of the optocoupler U4 begins to conduct, and the primary of U4 also enters the saturated conduction state at the same time, and the base of the transistor QP2 is powered through the diode DP1 and the voltage-stabilizing diode ZD6. The transistor QP2 also enters the saturated conduction state, at which time the base voltage of the transistor QP1 is pulled down, and the transistor QP1 begins to conduct, providing a reference voltage to the voltage regulator integrator U2 through the resistor RP4, the transistor QP1, the current limiters RP6 and RP7, and the voltage divider resistors RP8 and RP9. Voltage, AK pin of voltage regulator integrator U2 also starts to conduct and pulls the potential of pin 2 of relay K1 down to ground, current will flow through pins 1 and 2, and pins 3 and 4 of relay will start to close. After pins 3 and 4 of relay K1 are closed, the thermistor NTC1 connected in parallel with pins 3 and 4 of the relay is equivalent to being in a short-circuit state, so basically no current flows through the thermistor NTC1. According to the power calculation formula P=UI=RI2, the overall loss of the switching power supply is greatly reduced, thereby improving the energy efficiency of the whole machine.

[0048] Example 2

[0049] Based on Example 1, this embodiment provides a switching power supply, such as Figures 1 to 6 As shown, a control circuit capable of improving power supply energy efficiency as described in Example 1 is used and is set at both ends of the thermistor NTC1 to be short-circuited in the switching power supply circuit;

[0050] In a specific connection method, a control circuit capable of improving power supply energy efficiency as described in Example 1 is connected to both ends of a thermistor. The thermistor is short-circuited after the switching power supply starts working normally, so that substantially no current flows through the thermistor NTC1. According to the power calculation formula P=UI=RI2, the overall loss of the switching power supply is greatly reduced, thereby improving the energy efficiency of the entire device.

[0051] In this embodiment, connecting the control circuit capable of improving power supply energy efficiency described in Example 1 to both ends of the thermistor is merely an example. The control circuit can be connected to both ends of any device in the circuit that does not function after normal operation to short-circuit the device from the circuit.

[0052] In some embodiments, as Figures 1 to 6 As shown, the power switch circuit also includes an input circuit, a rectifier and filter module, a control module, and a transformer module; wherein the transformer module is the output module of the power supply;

[0053] Achievable, such as Figure 2 As shown, the input circuit includes fuses F1 and F2 connected in series in the circuit, a thermistor NTC1, a lightning protection device MOV1 connected in parallel at both ends of the input terminal, a filter capacitor CX1 connected in parallel at both ends of the input terminal after the rear end of the fuse F2, and a bridge balancing circuit;

[0054] The bridge balancing circuit includes four resistors, which are connected in series in pairs and then in parallel, and are connected by wires between them; the four resistors are resistor RX1, resistor RX2, resistor RX3 and resistor RX4;

[0055] The bridge balancing circuit composed of resistors RX1, RX2, RX3 and RX4 is used to adjust and distribute the voltage to ensure that the circuit voltage meets the design requirements.

[0056] The achievable rectifier and filter circuit includes an excitation coil LF1, a rectifier bridge stack BD1, and a primary filter capacitor EC1;

[0057] It is achievable to further include a primary absorption circuit, which is arranged in parallel at both ends of the primary coil of the transformer, including an RCD absorption circuit consisting of a resistor R1, a resistor R2, a resistor R3, a resistor R5, a resistor R4, a capacitor C2, and a diode D1.

[0058] In some embodiments, the transformer module, such as Figure 6 As shown, it includes a transformer T1, a transformer output circuit and a feedback circuit;

[0059] The voltage transformation output circuit includes: a first filter capacitor EC3, a resistor R20, a second filter capacitor C12, a third filter capacitor EC3 and an excitation coil LF2 connected in parallel between the positive and negative poles of the output terminal of the transformer T1.

[0060] The negative output terminal of transformer T1 is also connected to a diode D6 to prevent reverse current impact, and is also provided with parallel resistors R19 and R19A, which are connected in series to capacitor C8, and the other end of capacitor C8 is grounded;

[0061] Furthermore, the voltage conversion module further includes a second feedback circuit for providing a feedback signal to the control module, including a photoelectric coupler U3 and a voltage signal adjustment circuit thereof;

[0062] The voltage signal adjustment circuit includes a resistor R25, a secondary of the optocoupler U3, and a voltage regulator diode U31 connected in series; a resistor R26 is arranged in parallel at both ends of the secondary of the optocoupler U3, and one end of the resistor R26 is connected to the cathode of the optocoupler U3A, and the other end is connected to the capacitor C10 and the resistor R28; a resistor R29 and a resistor R30 are connected in parallel between the reference electrode and the anode of the voltage regulator integrator U31; a resistor R28 and a capacitor C11 are connected in series between the reference electrode and the cathode of the voltage regulator integrator U31; the resistor R25 and the two ends of the optocoupler U3 are connected in series and parallel with the capacitor C10, the capacitor C7, and the resistor R27.

[0063] Among them, the voltage regulator integrator U31 and the voltage regulator integrator U2 may be models TL431;

[0064] In some embodiments, the control module circuit is as follows Figure 4 As shown, it includes a control chip U1 and its peripheral circuits, wherein R and RJ plus labels in the peripheral circuits represent resistors, C and EC plus labels represent capacitors, and U3B is the primary of the photocoupler;

[0065] Optional, the main control chip U1, model can be Onbao OB2365EB;

[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

[0067] Although the above description of the specific implementation methods of the present invention is combined with the accompanying drawings, it does not limit the scope of protection of the present invention. Technical personnel in the relevant field should understand that on the basis of the technical solution of the present invention, various modifications or deformations that can be made by technical personnel in this field without creative work are still within the scope of protection of the present invention.

Claims

1. A control circuit capable of improving power supply energy efficiency, characterized in that: It includes a relay K1 and a relay control circuit; the relay control circuit includes a photoelectric coupler U4, a transistor QP1, and a transistor QP2 connected in sequence. The photoelectric coupler U4 is turned on to control the transistor QP2 to be turned on, and the transistor QP2 is turned on to control the transistor QP1 to be turned on. The transistor QP1 is connected to the coil terminal of the relay K1 to realize the on-off control of the coil of the relay K1; The primary side of the photocoupler U4 is connected to the first feedback terminal of the circuit to be controlled, and the secondary side of the photocoupler U4 is connected to the second feedback terminal of the circuit to be controlled.

2. The control circuit capable of improving power supply energy efficiency according to claim 1, wherein: The circuit to be controlled is a power circuit, both ends of the internal switch terminal of the relay K1 are connected in parallel to both ends of the thermistor in the power circuit, and the coil terminal of the relay K1 is connected to the relay control circuit.

3. The control circuit capable of improving power supply energy efficiency according to claim 2, wherein: The first feedback end is the input circuit of the power supply circuit, which provides a configuration voltage to the primary of the photocoupler U4 through the diode DC and the resistor RA3; the output end of the power supply circuit serves as the second feedback end and is grounded through the secondary of the photocoupler U4.

4. The control circuit capable of improving power supply energy efficiency according to claim 2, wherein: A first feedback circuit is set at the second feedback end, one end of the first feedback circuit is connected to the positive electrode of the power supply output circuit, and the other end is grounded; the first feedback circuit includes a resistor RP11 and a secondary of the photocoupler U4 connected in series, and the two ends of the secondary of the photocoupler U4 are connected in parallel with a resistor RP12.

5. The control circuit capable of improving power supply energy efficiency according to claim 1, wherein: The output end of the photocoupler U4 is connected to the base of the transistor QP2, and a fast on-off control circuit is provided between the photocoupler U4 and the transistor QP2; The fast on-off control circuit includes a diode DP1 and a transistor QP3. The base of the transistor QP2 is connected to the cathode of the diode DP1. After the connection, the anode of the diode DP1 is connected to the primary terminal of the optocoupler U4; the emitter of the transistor QP3 is connected to the cathode of the diode DP1, so that the diode DP1 and the transistor QP3 form a closed loop.

6. The control circuit capable of improving power supply energy efficiency according to claim 1, wherein: The collector of the transistor QP2 is connected to one end of the primary side of the photoelectric coupler U4 connected to the first feedback end through the resistors RP10 and RP5 , and the emitter of the transistor QP2 is grounded.

7. The control circuit capable of improving power supply energy efficiency according to claim 1, wherein: The base of transistor QP2 is also connected to a voltage stabilizing filter circuit, including a resistor RP3 and a capacitor CP1 connected in parallel between the base of QP2 and ground, and a voltage stabilizing diode ZD6; the anode of the voltage stabilizing diode ZD6 is connected to the base of transistor QP2, and the cathode of the voltage stabilizing diode ZD6 is connected to the cathode of the diode DP1 of the fast on-off control circuit.

8. The control circuit capable of improving power supply energy efficiency according to claim 1, wherein: The collector of the transistor QP2 is connected to the base of the transistor QP1 , and the emitter and collector of the transistor QP1 are respectively connected to one end of the primary side of the photocoupler U4 connected to the first feedback end.

9. The control circuit capable of improving power supply energy efficiency according to claim 1, wherein: A voltage stabilizing, filtering, and current limiting circuit is also provided on the connection path between the transistor QP1 and the coil terminal of the relay K1, including current limiting resistors RP6 and RP7, a voltage stabilizing diode ZD5, a capacitor CP3, a voltage dividing resistor RP8, and a voltage dividing resistor RP9 connected in sequence; the capacitor CP3 is connected across the voltage stabilizing diode ZD5; ​​and the voltage stabilizing diode ZD5 is connected between the reference electrode R and the anode of the voltage stabilizing integrator U2 via the voltage dividing resistors RP8 and RP9.

10. A switching power supply, comprising: a control circuit capable of improving power supply energy efficiency according to any one of claims 1 to 9, wherein: The control circuit is arranged at both ends of the thermistor to be short-circuited in the switching power supply circuit.

Images