High-reliability, high-efficiency and energy-saving switching power supply

Abstract

The invention relates to the technical field of electric energy conversion modes, and particularly discloses a high-reliability, high-efficiency and energy-saving switching power supply, which comprises a shell, and two amorphous magnetic rings, a control coil and two controlled coils which are positioned in the shell, the two amorphous magnetic rings are arranged in parallel, a controlled coil is wound on the outer side of each amorphous magnetic ring, and the two controlled coils are connected in series in the same direction; the control coil penetrates through the inner sides of the two amorphous magnetic rings to connect and wind the two amorphous magnetic rings, and the control coil is insulated from the controlled coil. The two controlled coils are wound in a double-wire parallel mode, and the number of winding turns of the two controlled coils is equal. The mechanism failure rate can be greatly reduced, and the service life is prolonged. The semi-permanent microcrystal module which is low in cost, simple to construct and use and extremely low in power consumption partially replaces a semiconductor device which bears high-speed switching risks. Especially, under the condition that multi-path output is required to be controlled respectively, the number of components can be greatly reduced, and the efficiency and the service life of the whole machine are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric energy conversion methods, and specifically refers to a highly reliable, energy-efficient switching power supply. Background Art

[0002] At present, the high-power switching power supplies we usually use mainly include two types: fixed-frequency pulse width modulation method and resonant frequency conversion modulation method.

[0003] 1. The fixed-frequency pulse width modulation method controls the output by changing the pulse width. Since the power semiconductor device faces large current and high voltage simultaneously, this circuit has high requirements for the switching performance and safe operating area of the power semiconductor device, and also has high requirements for the forward and reverse voltages and reverse recovery time of the secondary rectifier diode. Although the pulse absorption circuit can reduce the requirements for reverse voltage and recovery time, it also reduces the conversion efficiency of the whole machine. Currently, the highest efficiency of the isolated fixed-frequency pulse width modulation switching power supply is about 86% (taking 12V output as an example).

[0004] 2. The resonant frequency conversion modulation method solves the above problems well, but brings other problems; the current of the switching tube is several times larger than the average value. Moreover, the requirements for low loss of the resonant inductor and resonant capacitor and the current requirements for the power semiconductor device increase the cost. Currently, the highest efficiency of the isolated resonant frequency conversion modulation switching power supply reaches 93% (taking 12V output as an example).

[0005] Therefore, a highly reliable, energy-efficient switching power supply has become an urgent problem to be solved. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an energy-efficient switching power supply based on amorphous materials, which uses the principle of rapid switching between the establishment and saturation of the magnetic field of the amorphous material to switch alternating current.

[0007] To solve the above technical problem, the technical solution provided by the present invention is: a highly reliable, energy-efficient switching power supply, including a housing and two amorphous magnetic rings, a control coil, and two controlled coils located inside the housing;

[0008] The two amorphous magnetic rings are arranged in parallel, and a controlled coil is wound around the outside of each amorphous magnetic ring, and the two controlled coils are connected in series in the same direction;

[0009] The control coil passes through the inner sides of the two amorphous magnetic rings and is wound to connect the two, and the control coil and the controlled coil are insulated from each other.

[0010] Further, both of the two controlled coils are wound with two wires in parallel and the number of turns of the two is equal.

[0011] Furthermore, the two wires of one controlled coil lead out to the first pin and the fourth pin respectively, the two wires of the other controlled coil lead out to the second pin and the third pin respectively, and the two ends of the control coil lead out to the fifth pin and the sixth pin respectively.

[0012] Furthermore, the controlled coil is made of enameled wire.

[0013] Furthermore, the control coil is made of thin enameled wire.

[0014] Furthermore, the amorphous magnetic ring is made of cobalt-based microcrystalline material.

[0015] The advantages of the present invention compared with the prior art are:

[0016] 1. The present invention can significantly reduce the failure rate of the mechanism and increase the service life. The present invention is low-cost, simple in structure and use, and the semi-permanent microcrystalline module with extremely low power consumption partially replaces the semiconductor device that bears the risk of high-speed switching. Thereby greatly reducing the operating risk and extending the service life. In particular, the number of components can be greatly reduced in the case where multiple outputs are required to be controlled separately, thereby improving the efficiency and life of the whole machine.

[0017] 2. In the specific application of the present invention, the residual inductance is connected in series with the semiconductor switch element in the circuit, which reduces the current rise and fall rate in the circuit and staggers the phase of the voltage and current. Therefore, the conversion efficiency of the whole machine can be improved and the reliability can be enhanced. Alternatively, a semiconductor switch element with a lower switching rate can be used to reduce the cost while ensuring the performance of the whole machine.

[0018] 3. In the present invention, when the current flowing through the control coil is in the linear range, the output current pulse width approximately corresponds to the control current. Using this principle, the output voltage, current amplitude and frequency can be easily modulated. Using this function in electroplating equipment can help deep hole electroplating and increase the density of the coating. It is also meaningful for increasing the brightness. This function can be used for maintenance charging of the battery by the charging pile to reduce battery polarization and increase battery life. This function can be used in electric welding machines to make the weld smoother, thereby improving the welding quality. This function can also be used in occasions such as motor speed regulation that require variable frequency power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the circuit diagram of the amorphous magnetic ring saturation point test.

[0020] Figure 2 It is a structural schematic diagram of a highly reliable, efficient and energy-saving switching power supply of the present invention.

[0021] Figure 3A This is the waveform diagram of a magnetic ring with good performance.

[0022] Figure 3BIt is the waveform diagram where the magnetic ring is not applicable.

[0023] Figure 4 It is the working magnetic field diagram of a highly reliable, energy-efficient switching power supply according to the present invention.

[0024] Figure 5 It is the circuit schematic diagram of the power supply for a cryostat microtome according to the present invention.

[0025] Figure 6 It is the circuit schematic diagram of the multi-output communication switching power supply according to the present invention.

[0026] As shown in the figure: 1. Outer shell, 2. Amorphous magnetic ring, 3. Control coil, 4. Controlled coil, 5. First pin, 6. Second pin, 7. Third pin, 8. Fourth pin, 9. Fifth pin, 10. Sixth pin. Detailed implementation mode

[0027] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "vertical", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and 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, and therefore should not be construed as a limitation to the present invention.

[0028] In the description of the present invention, the "first feature" and "second feature" may include one or more of such features. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0029] In the present invention, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] The following further details a highly reliable, energy-efficient switching power supply according to the present invention with reference to the drawings.

[0031] The working principle of the present invention:

[0032] The present invention relates to an efficient energy-saving switching power supply based on amorphous materials. This switching power supply uses the principle of rapid switching between the establishment and saturation of the magnetic field of amorphous materials to switch alternating current, so the present invention is applicable to low and medium voltage high-frequency AC power supply occasions. When the main power supply is DC power supply, the power supply should be simply converted into a rectangular wave power supply with a fixed frequency.

[0033] The present invention is particularly suitable for application occasions of multi-output DC or low-frequency pulse modulation DC, such as electroplating power supply, communication power supply, electrochemistry power supply, solar energy converter, electric welding machine, low-frequency modulation high-power power supply. It can also be used as a simple-structured multi-phase low-frequency variable frequency power supply for driving a variable frequency vibration table and driving motors and other applications. It is also expected to be used in electric vehicles as a hub drive unit to cancel differential mechanisms, speed regulators, etc., and save electric energy to the greatest extent.

[0034] In the present invention, the signal used to control high-power output only requires a few volts and dozens of milliamperes of DC or low-frequency alternating current.

[0035] The working principle of the present invention is similar to that of thyristors, but the differences in performance are as follows:

[0036] 1. The present invention allows the product of voltage and time to be applied across the two ends of the controlled coil 4. Therefore, the present invention is applicable to AC (square wave) circuits above 10KHZ and works in a switching state. Since the module is an inductor and theoretically does not consume power, its own power consumption is small. The switching tube that supplies power to the module works at a fixed pulse width and frequency, and the pulse width modulation is borne by the low-power-consuming module. This causes the phase of the current conduction to lag due to the inductance of the module when the switching tube that supplies power to the module starts to conduct. (At the limit of full conduction of the module, the residual inductance of the module still plays a role.) Thus, it is avoided that the switching tube that supplies power to the module works under high voltage and large current at the same time, reaching the limit far from the safe operating area, and greatly improving the power efficiency and reliability of the power supply. As for the flyback current when the switching tube that supplies power to the module is turned off, the internal diode of the switching tube returns it to the power supply, and only when the frequency of this diode is insufficient, a high-frequency diode needs to be added externally.

[0037] 2. The conduction voltage drop of the present invention can be as small as 0.1V, and the sum of the copper loss of its coil and the magnetic ring loss is less than 1% of the controlled power. This is particularly useful for low-voltage large-current circuits.

[0038] 3. The breakdown of the present invention is reversible, and its overload resistance ability is extremely strong, and it is a semi-permanent component.

[0039] 4. The current applied to the control coil 3 of the present invention can be direct current, low-frequency pulse or low-frequency alternating current with positive and negative symmetry, and it is isolated from the controlled coil 4, which is very useful in circuit design.

[0040] Combined with the attached Figures 1-6 , the present invention will be introduced in detail.

[0041] A highly reliable and energy-efficient switching power supply includes a housing 1 and two amorphous magnetic rings 2, a control coil 3, and two controlled coils 4 inside the housing 1; the housing 1 is used to protect the internal components.

[0042] The controlled coils 4 are wound around the outer sides of the two amorphous magnetic rings 2 respectively, and the two controlled coils are connected in series in the same direction. The controlled coils 4 are double-wound with enameled wire, and the number of turns of the two controlled coils 4 is equal.

[0043] The control coil 3 is composed of fine enameled wire wound through the inner sides of the two amorphous magnetic rings 2 at the same time.

[0044] There should be sufficient insulation between the control coil 3, the two controlled coils 4, and the two amorphous magnetic rings 2.

[0045] The two amorphous magnetic rings 2 are made of cobalt-based microcrystalline materials.

[0046] The two wires of one controlled coil 4 are respectively led out as the first pin 5 and the fourth pin 8, and the two wires of the other controlled coil 4 are respectively led out as the second pin 6 and the third pin 7. The two ends of the control coil 3 are respectively led out as the fifth pin 9 and the sixth pin 10.

[0047] The controlled coil 4 is a thick wire coil wound in two groups in the same direction and equally wound around the outer sides of the two amorphous magnetic rings 2, and the two groups are connected in series.

[0048] The control coil 3 is a thin wire coil wound through the inner sides of the two amorphous magnetic rings 2 at the same time.

[0049] The two amorphous magnetic rings 2 work under the alternating power supply, repeatedly working under the conditions of magnetization and magnetic saturation, reverse magnetization and reverse magnetic saturation;

[0050] The specific implementation process of the highly reliable and energy-efficient switching power supply of the present invention is as follows:

[0051] 1. Amorphous magnetic ring saturation point test

[0052] Combined with the attached Figure 1 , the selected amorphous magnetic ring 2 is made of cobalt-based amorphous material, which can make the leakage current of the composed module less before saturation, the working frequency higher, and the saturation point curve change sharply at a right angle, so the switching loss is small and the conversion efficiency is high.

[0053] The working frequency is generally selected between 20 - 200 kHz.

[0054] Test method:

[0055] First, wind 10 - 20 turns of wire around a tested amorphous magnetic ring 2, and the wire diameter can be 0.5 - 1 mm. Adjust the potentiometers for voltage and time in the amorphous magnetic ring 2 saturation point test circuit to the minimum.

[0056] Monitor the time-current waveform with an oscilloscope (apply time to the Y2 input, current to the Y1 input, and synchronize time with Y2), connect the coil, and slowly adjust the voltage and time from small to large; the voltage should not be lower than 10V. It will be seen that the coil current is very small at the beginning. At a certain point as both are increased, the current suddenly increases, indicating that this magnetic core is suitable for making the product of the present invention. Record the applied voltage (V) and pulse width (t) in μS at this time, multiply the two and divide by the number of turns (T) wound to obtain the Vt / T value of this magnetic core. The magnetic core uses cobalt-based amorphous material. Taking an outer diameter of 20 - 36mm as an example, the Vt / T value is approximately in the range of (5 - 30) * 10^ -6 . In addition, when measuring in this circuit, it is best to set the leakage current saturation point to a small value (such as 100mA). Of course, if the load allows a larger leakage current, it can also be set larger to reduce the volume of the control coil 3. The magnetic core can also be fully utilized. The test data of some microcrystalline magnetic cores are shown in Table 1 below.

[0057] Table 1: Test data table of some microcrystalline magnetic cores

[0058]

[0059] When the operating frequency is relatively low (5 - 20kHz), an iron-based alloy magnetic core can also be used. It can control a larger power, but the leakage current (saturation) is relatively large. It depends on whether the load allows this current.

[0060] Combined with Appendix Figure 3A , this waveform is one of the examples obtained from the saturation point test circuit of the amorphous magnetic core 2 in Appendix Figure 1 . The characteristics of this waveform are as follows: when t ≤ 15μS, the current flowing through the magnetic core coil < 100mA. When t = 17μS, the current flowing through the magnetic core coil > 1.8A. Obviously, there is a current-time turning point at t = 15 - 17μS.

[0061] Combined with Appendix Figure 3B , this waveform is also one of the examples obtained from the saturation point test circuit of the amorphous magnetic core 2 in Appendix Figure 1 . The characteristics of this waveform are as follows: after t starts, the current flowing through the magnetic core coil increases linearly. When t is only 3.5μS, the current has reached 25A. Obviously, there is no hysteresis phenomenon and it cannot be used in the switching state.

[0062] 2. Principle derivation and specific examples of the present invention

[0063] (1) Introduction to the principle of the example

[0064] Combined with Appendix Figure 4, here we further define I2*T2 as the specific parameter of the control coil 3 at the saturation point of the amorphous magnetic ring 2, where: T2 is the number of turns of the control coil 3, and I2 is the current flowing through the control coil 3. The two parameters should be designed to each occupy 35 - 45% of the winding space of the coil, and the voltage of the control coil 3 should not be too high to avoid complicating the circuit.

[0065] Among them, T1 is obtained by the Vt / T conversion measured previously. Since the controlled coil 4 is evenly distributed on two magnetic cores (amorphous magnetic rings 2), the coil voltage on one magnetic core only bears half of the maximum voltage of the controlled coil 4. This point should be noted during the calculation.

[0066] Only after the module enters magnetic saturation does it have the opportunity to further develop into a deep saturation state, and only when it enters the deep saturation state will the voltage drop be very low. This is divided into three states;

[0067] a: After the two magnetic rings form a module, its turning point is: I2*T2, ---- when magnetic saturation is caused solely by the control coil 3;

[0068] b: Or 2I1*T1. --- when the voltage * time of the controlled coil 4 is overloaded;

[0069] c: Or (n)I2*T2+(1 - n)2I1*T1. (where n ≤ 1), --- when both the control coil 3 and the controlled coil 4 are in effect;

[0070] Obviously, state a cannot occur. State b only occurs when the circuit is abnormal. State c is the normal state. State c is further divided into the state where the control coil 3 has no current and the state where it has current; that is, states c1 and c2.

[0071] c1: At this time, if I2T2 = 0, that is, the control coil 3 has no current, and the total voltage applied to the two series-connected coil ends of the controlled part is 2Vt. As long as 2Vt does not exceed the standard, only a small amount of leakage current passes through the controlled coil 4 at this time. Since the number of turns of the controlled coil 4 is generally very small, that is, 2I1T1 → 0, it is far from being able to saturate the module. At this time, the module can be regarded as an open circuit.

[0072] c2: When the control coil 3 is energized to (n)I2T2, the magnetic fields of the two magnetic rings in the positive half-cycle state of the applied voltage are: Attached Figure 4 Among them, in the left figure, the magnetic field of the left ring of the left figure weakens by a variable, which causes the reactance of the controlled coil 4 to decrease. The magnetic field of the right ring of the left figure seems to increase by the same variable. However, as t increases, at (n)*2Vt, it encounters the current - time turning point and the reactance decreases significantly. Moreover, I2T2 also contributes to pushing the module into saturation. The three factors that increase the current consistently push the module into deep saturation. At this time, the conduction angle is theoretically n.

[0073] It should be pointed out that the control of the conduction angle is not precise. It is restricted by the magnetic ring process, coil process and temperature. To overcome this phenomenon, closed-loop control is required.

[0074] When the time reaches t, the polarity of V reverses and the two magnetic rings exit saturation. Then the negative half cycle magnetic field reverses (see attached Figure 4 The magnetic field direction diagram on the right side) is the same as the working condition because the magnetic ring and the coil are symmetrical. It should be noted that the module works in the first and third quadrants alternately and is not allowed to work continuously in one or three quadrants. (See attached Figure 5 In the PWM regulation, MFE1 and D13 are connected. The coil end with a small dot is the same end, which is the controlled coil 4. The end without a small dot is the control coil 3. When working, the two controlled coils 4 are energized in the positive and negative half cycles in turn. There is no small dot at the end of the control coil 3, which means that no polarity is required, because the change of the power supply direction of the control coil 3 only causes the exchange of the left and right magnetic ring working states, and does not affect other.

[0075] (2) Controlled coil design

[0076] Press Attach Figure 1 The measurement method is as follows: Taking the cobalt-containing amorphous magnetic ring 2 with an outer diameter of 24, an inner diameter of 11.5, and a height of 13.5 as an example, the saturation characteristics of the amorphous magnetic ring 2 are first tested; the voltage (V)*time (t)=12*10 is measured by winding 10 circles around the magnetic ring. ＾6 , and Vt / T=12.

[0077] The total window section of the center hole of the magnetic ring through which the coil is wound is 104mm 2 , the controlled coil 4 and the control coil 3 each account for 35-45% in the cross section, which is more reasonable. The power added by the module is a 50kHz rectangular wave (positive and negative t = 10us), and the voltage peak is 12V / T. Because two magnetic rings are used, each ring is 24V.

[0078] Special attention: Pay attention to the voltage peak value when designing, and do not allow too much margin within the available range. Otherwise, the control will be insensitive, resulting in a very high voltage being added to the control coil 3 to generate output. If the designed module has a low power supply voltage, a magnetic ring with a smaller height can be selected, which has a lower Vt / T value and is more suitable for low voltage use.

[0079] Assume the input limit voltage is 192V (standard 148V), the left and right amorphous magnetic rings 2 each account for half of the number of turns = 96 (V) / 12 (V / T) = 8 (turns). The left and right groups have a total of 16 turns (192V). The winding method is to use double wires from bottom to top on the left side of the left magnetic ring and wind 8 turns, then turn to the right side of the right magnetic ring, and continue to use wires from top to bottom and wind 8 turns. The two coils must be wound in the same direction. For easy identification, the two wires can be wound with enameled silk wires of different colors.

[0080] Each wire of the controlled coil 4 has a diameter of 1.25 mm and a cross-section of 1.227 mm 2 , calculated at 6 A / mm 2 , the average current is 7.36 A. Since the pulse occupancy is 1 / 2. The total current, i.e., the double-wire current, is 14.72 A. The single-wire length = the length of each turn of wire + the extra length of the wire head * 8 turns / = 0.91 m. The resistance (70 °C) = the resistivity at 70 degrees * 0.91 m / the cross-section = 16 mΩ. The voltage drop per wire is 118 mV. The copper loss of the two groups of coils is 1.735 W. It can control a power of 148 V * 14.7 A = 2176 W. There is also a voltage margin of 192 / 148 = 30%. The controlled coil 4 with insulation, calculated by the maximum outer diameter of 1.38, for 8 turns * 2, the total cross-section occupied is 30.47 mm 2 , which is 29.3% of the total cross-section of 104 mm 2 . It is within a reasonable range.

[0081] (3) Design of the control coil

[0082] Previously, it was obtained that each loop of the controlled coil 4 has 8 turns and a current of 14.7 A, that is, it saturates when At = 120. If the control coil 3 has 1300 turns, that is, by applying a current of 92.3 mA, the output can be reliably controlled. The average length of each turn of the control coil 3 * 1300 turns = 131 m. If calculated with a wire of 0.17, the resistance (70 °C) == 125 Ω, that is, a voltage of 11.54 V can be used for control, and the control power is 1.065 W. The control coil 3 with insulation, calculated by the maximum cross-section of 0.0362 mm 2 , the cross-section occupied is 0.0362 * 1300 = 47 mm 2 , which is 45.1% of the total cross-section of 104 mm2. It is also within the allowable range.

[0083] (4) Magnetic ring loss

[0084] The loss of this magnetic ring at 50 KC is not more than 220 W / KG. The weight of two magnetic rings is 26 g, which is 5.72 W. The total power consumption of the magnetic rings of the controlled coil 4 is 7.46 W. At this time, the temperature rise of the module is not higher than 40 degrees. The self-consumption power of the module is 7.46 / 2176 = 0.0034, that is, the module efficiency reaches as high as 99.6%.

[0085] The above is the calculation for the module composed of two small cobalt-based amorphous magnetic rings. If a higher temperature rise of the module is allowed, the current of the controlled coil 4 can be increased, and the controllable power can be increased significantly.

[0086] 3. Description of the application of the present invention to the power supply of a cryostat microtome

[0087] Combined with the attached Figure 5, this example is to test the main schematic diagram of the disconnector power supply of the present invention. Its secondary PWM regulation has two modules, MFE1 and MFE2, and a total of 100 units are produced. It is a refrigeration source with 2 channels of separate regulation of 2*12V / 15A. After sampling 5 units to test the conversion efficiency, it is between 87.58 - 88%. At present, the efficiency of the PWM switching power supply of this specification, which is relatively advanced in China, is only about 85% (the output is 12V).

[0088] 4. Description of the application of the present invention to a multi-output communication switching power supply

[0089] Combined with the attached Figure 6 , the present invention is applied to a multi-output communication switch. The lumped switching power supply therein uses 4 VMOS transistors with a on-state resistance of more than a dozen milliohms and a rating of 75A60V to efficiently convert two groups of 24V power supplies into +-24V, 40KC square waves. The three groups of modules are designed at a peak value of 36V and actually operate normally at 18 - 28V. A 45V Schottky diode can be used for secondary rectification. After preliminary calculation, the efficiency of this circuit is expected to exceed 90%.

[0090] The drive of the electric vehicle hub motor can also refer to the attached Figure 6 improvement, which can achieve the cancellation of the differential and gearbox. Greatly improve the power consumption efficiency, simplify the overall vehicle structure, and further improve the intelligent level of the electric vehicle.

[0091] The present invention and its implementation manners have been described above. This description is not restrictive. What is shown in the drawings is only one of the implementation manners of the present invention, and the actual structure is not limited thereto. All in all, if those of ordinary skill in the art are inspired by it and, without departing from the gist of the present invention, design similar structural manners and embodiments to this technical solution without creative efforts, they shall fall within the protection scope of the present invention.

Claims

1. A highly reliable, efficient and energy-saving switching power supply, characterized in that: It includes a shell, two amorphous magnetic rings, a control coil, and two controlled coils in the shell; Two amorphous magnetic rings are arranged in parallel, and a controlled coil is wound around the outside of each amorphous magnetic ring, and the two controlled coils are connected in series in the same direction; The control coil passes through the inner sides of two amorphous magnetic rings to connect and wind the two, and the control coil and the controlled coil are insulated from each other.

2. A highly reliable, efficient and energy-saving switching power supply according to claim 1, characterized in that: The two controlled coils are both wound in parallel with two wires and the number of turns of the two coils is equal.

3. A highly reliable, efficient and energy-saving switching power supply according to claim 2, characterized in that: The double wires of one controlled coil lead out to the first pin and the fourth pin respectively, the double wires of the other controlled coil lead out to the second pin and the third pin respectively, and the two ends of the control coil lead out to the fifth pin and the sixth pin respectively.

4. A highly reliable, efficient and energy-saving switching power supply according to claim 3, characterized in that: The controlled coil is made of enameled wire.

5. A highly reliable, efficient and energy-saving switching power supply according to claim 4, characterized in that: The control coil adopts a thin enameled wire.

6. A highly reliable, efficient and energy-saving switching power supply according to claim 5, characterized in that: The amorphous magnetic ring is made of cobalt-based microcrystalline material.

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