Coil component, coil component complex, transformer and power supply unit

Abstract

Coil assembly element, comprising: a coil pattern (110, 120, 130, 140, 120A, 130A, 220) arranged on a substrate and comprising a plurality of separate end sections (121, 131), wherein the separate end sections (121, 131) are separated by a gap between them; and a conduction element (160) that allows selective electrical conduction between the respective separated end sections (121, 131), wherein the selective electrical conduction causes a change in the number of turns of the coil pattern (110, 120, 130, 140, 120A, 130A, 220), wherein Each of the separate end sections (121, 131) in the coil pattern (110, 120, 130, 140, 120A, 130A, 220) forms a part of the coil element, regardless of the number of turns, wherein the substrate comprises a multilayer substrate comprising a surface layer (101) and one or more internal layers (102, 103), the coil pattern (110, 120, 130, 140, 120A, 130A, 220) is arranged in one or more of the inner layers (102, 103) of the multilayer substrate, each of the multiple separate end sections (121, 131) has one or more turn-number selection via holes (210, 211, 212, 310, 311, 312), the multitude of separate end sections (121, 131) includes a separate winding start end section and a separate winding end end section, Each of the separate winding start-end section and the separate winding end-end section has a winding number selection via hole, and one or more of the separate end sections (121, 131) that are neither the separate turn start end section nor the separate turn end end section, have two or more turn number selection via holes (210, 211, 212, 310, 311, 312), wherein the conducting element (160) is arranged on the surface layer (101) or on and from the surface layer (101) into the turn selection via holes (210, 211, 212, 310, 311, 312) to create a conducting bridge between one of the turn selection via holes (210, 211, 212, 310, 311, 312) in one of the separated end sections (121, 131) and one of the turn selection via holes (210, 211, 212, 310, 311, 312) in another of the separated end sections (121, 131), wherein the conducting bridge allows selective electrical conduction between the respective separated end sections (121, 131).

Description

background

[0001] The invention relates to a coil component, a coil component complex and a transformer, each provided on a printed circuit board, and a power supply unit containing such a coil component, etc.

[0002] In recent years, various car manufacturers have released a wide range of environmentally friendly vehicles, from luxury cars to standard models. These environmentally friendly vehicles can be classified as hybrid vehicles. In such vehicles, a high-voltage hybrid (HV) battery, operating in the range of 100 V to approximately 400 V, serves as an electrical energy source to store the energy used for driving. For example, reference is made to the Japanese unexamined patent applications with publication numbers H08-69935 (JP H08 - 69 935 A), H09-92537 (JP H09 - 92 537A), 2013-26556 (JP2013 - 26 556 A) and H03-183106 (JP H03 - 183 106 A), and Japanese patent no. 3223425 (JP 3 223 425 B).

[0003] US 6 404 317 B1, US 2013 / 0 038 387 A1 and US 6 590 486 B2 each show a coil component known in the prior art. SUMMARY

[0004] High-voltage (HV) batteries have varying voltages depending on their intended use, price, size, and vehicle class. Typical voltage ranges are shown, for example, in... Fig. 16 shown. With reference to Fig. For example, voltages in the range of 100 V to 200 V, 200 V to 300 V and 300 V to 400 V can be used for the HV batteries.

[0005] In addition to the high-voltage (HV) battery, each of these environmentally friendly vehicles is equipped with a 12V lead-acid battery to power electrical components. A DC-DC converter in the vehicle converts the voltage of the HV battery to a voltage suitable for the lead-acid battery. A matching transformer (MT), also known as an isolation transformer, is used for the DC-DC converter for power conversion and isolation. The optimal number of turns in the coil of the isolation transformer depends on the voltage range of the HV battery, as illustrated in the example below. Fig. Figure 16 illustrates this. For example, in order to support the three voltage ranges as described above, isolation transformers, which differ from each other in the number of turns, must be custom-made in these cases. In the Fig. In the example shown in Figure 16, the number of turns is 8 turns (8 Ts) for the voltage range of 100 V to 200 V, 10 turns (10 Ts) for the voltage range of 200 V to 300 V and 12 turns (12 Ts) for the voltage range of 300 V to 400 V.

[0006] JP H08 - 69 935 A, JP H09 - 92 537 A, JP 3 223 425 B, JP2013 - 26 556 A and JP H03 - 183 106 A each disclose an example in which a coil component is designed using a conductor-coil pattern. Some of them disclose an exemplary setup in which the number of turns of the coil component is made variable. However, the coil components described in JP H08 - 69 935 A, JP H09 - 92 537 A, JP 3 223 425 B, JP2013 - 26 556 A and JP H03 - 183 106 A still have room for improvement, for example, in that a variety of substrates that differ from each other in the number of turns have to be manufactured in JP H08 - 69 935 A, in that there are samples that do not function as coils and are therefore wasted when the number of turns varies in JP H09 - 92 537 A, and so on.

[0007] It is desirable to provide a coil element, a coil element complex and a transformer, each of which makes it possible to easily vary the number of turns, and a power supply unit that includes a power supply circuit device designed by such a coil element or the like.

[0008] A coil element according to one embodiment of the invention comprises, among other things: a coil pattern provided on a substrate and comprising a plurality of separate end sections separated from one another by a gap between them; and a conduction element that allows selective electrical conduction between the respective separate end sections. The selective electrical conduction causes a change in the number of turns of the coil pattern. Each section in the coil pattern forms a part of the coil element, independent of the number of turns.

[0009] A transformer according to one embodiment of the invention comprises, among other things: a primary winding; and a secondary winding. One of the primary and secondary windings comprises: a coil pattern provided on a substrate and comprising a plurality of separate end sections separated from one another by a gap between them; and a conduction element that allows selective electrical conduction between the respective separate end sections. The selective electrical conduction effects a change in the number of turns of the coil pattern. Each section in the coil pattern forms a part of the coil element, independent of the number of turns.

[0010] A coil assembly according to one embodiment of the invention comprises, among other things: a first coil assembly; and a second coil assembly electrically coupled to the first coil assembly. The first coil assembly comprises: a coil pattern provided on a substrate and comprising a plurality of separate end sections separated from one another by a gap between them; and a conduction element that allows selective electrical conduction between the respective separate end sections. The selective electrical conduction causes a change in the number of turns of the coil pattern. Each section in the coil pattern forms a part of the coil assembly, independent of the number of turns.

[0011] A power supply unit according to one embodiment of the invention comprises, among other things, a power supply circuit device formed by a coil element. The coil element comprises: a coil pattern provided on a substrate and comprising a plurality of separate end sections separated from one another by a gap between them; and a conduction element that allows selective electrical conduction between the respective separate end sections. The selective electrical conduction causes a change in the number of turns of the coil pattern. Each section in the coil pattern forms a part of the coil element, independent of the number of turns.

[0012] In the coil element, coil element complex, transformer and power supply unit according to the embodiments described above, the separate end sections are selectively brought into electrical conduction with each other in order to vary the number of turns of the coil pattern, with each section in the coil pattern forming a part of the coil element, regardless of the number of turns.

[0013] In the coil element, coil element complex, transformer, and power supply unit according to the embodiments described above, the separate end sections are selectively connected to each other in an electrical conduction manner to vary the number of turns of the coil pattern. When the number of turns of the coil pattern is changed, each section in the coil pattern forms a part of the coil element, independent of the number of turns.

[0014] Therefore, it is possible to easily vary the number of turns without having to produce a variety of substrates or causing a wasted pattern, regardless of the change in the number of turns. Brief description of the drawing

[0015] The drawing depicts embodiments and, together with the description, serves to explain the principles of the invention. Fig. Figure 1 is a block diagram that illustrates an example of a design of a power supply unit according to an embodiment of the invention. Fig. 2 a cross-sectional view of an example of a multi-layer substrate. Fig. Figure 3 is a top view of an example of a coil pattern of a first layer structuring a coil element according to an embodiment of the invention. Fig. Figure 4 is a top view of an example of a second layer coil pattern structuring the coil component. Fig. Figure 5 is a top view of an example of a third-layer coil pattern structuring the coil device. Fig. Figure 6 is a top view of an example of a fourth layer coil pattern structuring the coil component. Fig. Figure 7 is a perspective view of an example of core assembly and a jumper connection. Fig. Figure 8 is a top view of a connection in the second layer coil pattern in an example where the number of turns is selected to be four. Fig. Figure 9 is a top view of a connection in the second layer coil pattern in an example where the number of turns is selected to be five. Fig. Figure 10 is a top view of a connection in the second layer coil pattern in an example where the number of turns is selected to be six. Fig. Figure 11 is a top view of an example of a configuration in which the selection of the number of turns of the coil pattern is carried out using switching devices. Fig. Figure 12 is a top view of an example of a configuration where the selection of the number of turns of the coil pattern is carried out using connecting conductors. Fig. Figure 13 is a top view of an example of a coil pattern of a second layer in the coil component according to a modification example. Fig. Figure 14 is a top view of an example of a coil pattern of a third layer in the coil device according to the modification example. Fig. Figure 15 is a top view of an example where the number of turns in a coil pattern is fixed at four turns according to the comparison example. Fig. 16 describes an example of a relationship between the voltage range of an HV battery and the number of turns of an isolation transformer. Detailed description

[0016] Some exemplary embodiments of the invention are described in detail below with reference to the accompanying drawing. The description follows the sequence below. 1. Switching power supply unit 1.1 Configuration 1.2 Operation 2. Coil component (Transformer 20) 2.1 Configuration and Implementation 2.2 Effect 3. Modification example of the coil component 4. Other embodiments [1. Switching Power Supply Unit][1.1 Configuration]

[0017] Fig. Figure 1 shows an example of a design of a switching power supply unit 1 according to an embodiment of the invention.

[0018] The switching power supply unit 1 can be used, for example, as a vehicle DC-DC converter, but its applications are not limited to this. The switching power supply unit 1 can perform a voltage conversion (such as a step-down conversion) of a DC voltage Vin to generate an output DC voltage Vout, and supply this output voltage Vout to a low-voltage battery BL via output terminals T3 and T4. The DC voltage Vin can be supplied by a high-voltage battery BH, which is connected to input terminals T1 and T2. The high-voltage battery BH can be a battery that stores electrical energy and has a voltage in the range of approximately 100 V to approximately 500 V. The low-voltage battery BL can be a battery that stores electrical energy and has a voltage in the range of approximately 12 V to approximately 15 V.

[0019] The switching power supply unit 1 can include an input smoothing capacitor Cin, a turns number controller 5, voltage measurement circuits 7 and 9, a current measurement circuit 8, a switching circuit 10, a resonant coil Lr, a transformer 20 (such as an isolation transformer), a rectification circuit 30, a smoothing circuit 40, a controller 50 and a computer 69.

[0020] The input smoothing capacitor Cin can be placed between a primary high-voltage line L1H and a primary low-voltage line L1L and serves to smooth the input DC voltage Vin supplied via input terminals T1 and T2 from the high-voltage battery BH. The primary high-voltage line L1H can be connected to input terminal T1. The primary low-voltage line L1L can be connected to input terminal T2.

[0021] The voltage measurement circuit 7 can be provided between the primary high-voltage line L1H and the primary low-voltage line L1L and serve to measure the input DC voltage Vin across the input terminals T1 and T2 and output a measurement signal corresponding to the measured input voltage Vin to the computer 69. For example, the voltage measurement circuit 7 can have a non-restrictive circuit configuration in which a voltage across a voltage divider resistor (not shown) provided between the primary high-voltage line L1H and the primary low-voltage line L1L is measured, and a voltage corresponding to the measured voltage is generated.

[0022] The current measurement circuit 8 can be provided between the input terminal T1 and the switching circuit 10 in the primary high-voltage line L1H and serves to measure an input current Iin flowing in the primary high-voltage line L1H and outputs a measurement signal corresponding to the measured input current Iin to the computer 69. For example, the current measurement circuit 8 can have a non-restrictive circuit configuration that includes a current transformer.

[0023] The switching circuit 10 can be a full-bridge circuit that converts the input voltage Vin into an alternating voltage. The switching circuit 10 can include the switching components SW11 to SW14.

[0024] The switching devices SW11 to SW14 can each be a device such as a metal-oxide-semiconductor field-effect transistor (MOSFET), an insulated-gate bipolar transistor (IGBT), or any other suitable device, without being limited to these. In the present example embodiment, all switching devices SW11 to SW14 can be N-channel MOSFETs. For switching device SW11, a SW control signal S11 can be applied to one gate, a source can be coupled to a drain of switching device SW12, and a drain can be coupled to the primary high-voltage line L1H. For switching device SW12, a SW control signal S12 can be applied to one gate, a source can be coupled to the primary low-voltage line L1L, and the drain can be coupled to the source of switching device SW11.In switching element SW13, a SW control signal S13 can be applied to a gate, a source can be coupled to a drain of switching element SW14, and a drain can be coupled to the primary high-voltage line L1H. In switching element SW14, a SW control signal S14 can be applied to a gate, a source can be coupled to the primary low-voltage line L1L, and the drain can be coupled to the source of switching element SW13. The source of switching element SW11 and the drain of switching element SW12 can also be coupled to a first end of the primary winding 21 of transformer 20. The source of switching element SW13 and the drain of switching element SW14 can be coupled to a second end of the primary winding 21 of transformer 20 via the resonant coil Lr.The resonant coil Lr can be used, together with the parasitic capacitances in the switching components SW11 to SW14 and a stray inductance of the transformer 20, to design a predetermined LC resonant circuit.

[0025] With this configuration, the switching circuit 10 can switch the switching components SW11 to SW14 on and off in response to their respective control signals S11 to S14, which are supplied by an SW control section 55 in the controller 50, in order to convert the input voltage Vin into the alternating voltage.

[0026] Transformer 20 can galvanically isolate a primary and a secondary side from each other and couple the primary and secondary sides together in AC. Transformer 20 can be a three-winding transformer comprising primary winding 21 and secondary windings 22A and 22B. Primary winding 21 of transformer 20 can be coupled to secondary windings 22A and 22B of transformer 20 via a forward connection. The first end of primary winding 21 can be coupled to switching circuit 10. The second end of primary winding 21 can be coupled to switching circuit 10 via the resonant coil Lr. A first end of secondary winding 22A and a first end of secondary winding 22B can be coupled to rectifying circuit 30.A second end of the secondary winding 22A and a second end of the secondary winding 22B can be coupled together at a center tap CT, in order to be further coupled to a secondary high voltage line L2H.

[0027] The number of turns of the primary winding 21 can be defined as Np, while the number of turns of each of the secondary windings 22A and 22B can be defined as Ns. A ratio Np:Ns of the number of turns of the primary winding 21 to the number of turns of each of the secondary windings 22A and 22B can be, for example, 10:1, but is not limited to this. Note, however, that the number of turns Np of the primary winding 21 of the transformer 20 is variable, and the number of turns Np is set to any desired number as needed. The turn controller 5 can control the number of turns Np of the primary winding 21 of the transformer 20 in an embodiment where the number of turns Np can be variably controlled, as described below.For example, the turns controller 5 can control the number of turns Np of the primary winding 21 of the transformer 20 on the basis of a measurement signal corresponding to the input voltage Vin measured by the voltage measurement circuit 7.

[0028] With this configuration, the transformer 20 can reduce the AC voltage applied across both ends of the primary winding 21 to an AC voltage that is Ns / Np times smaller than the applied AC voltage and output the reduced AC voltage at the secondary windings 22A and 22B.

[0029] The rectifying circuit 30 can rectify the alternating voltage supplied by the transformer 20. The rectifying circuit 30 can include diodes 31 and 32. The cathode of diode 31 can be connected to the first end of the secondary winding 22B, and the anode can be connected to a secondary low-voltage line L2L. The cathode of diode 32 can be connected to the first end of the secondary winding 22A, and the anode can be connected to the secondary low-voltage line L2L.

[0030] The smoothing circuit 40 can comprise an inductor Lch and an output smoothing capacitor Cout. The inductor Lch can be positioned in the secondary high-voltage line L2H, with one end connected to the center tap CT of the transformer 20 and the other end connected to terminal T3. The output smoothing capacitor Cout can be positioned between the secondary high-voltage line L2H and the secondary low-voltage line L2L. The secondary high-voltage line L2H can be connected to terminal T3, and the secondary low-voltage line L2L can be connected to terminal T4.

[0031] With this configuration, the smoothing circuit 40 can smooth a signal that is rectified by the rectifying circuit 30 and output at the center tap CT to generate the output DC voltage Vout and supply the output voltage Vout to the low-voltage battery BL. The low-voltage battery BL can be connected between the output terminals T3 and T4.

[0032] The voltage measurement circuit 9 can be placed between the secondary high-voltage line L2H and the secondary low-voltage line L2L and serves to measure the output voltage Vout across the output terminals T3 and T4 and to output a measurement signal corresponding to the measured output voltage Vout to the controller 50. As with the voltage measurement circuit 7, the voltage measurement circuit 9 can, for example, have a non-restrictive circuit configuration in which a voltage across a voltage divider resistor (not shown) placed between the secondary high-voltage line L2H and the secondary low-voltage line L2L is measured, and a voltage corresponding to the measured voltage is generated.

[0033] The controller 50 can thus control the switching operation performed in the switching circuit 10 based on a measurement result of the output voltage Vout, derived from the voltage measurement circuit 9, in order to ensure that the output voltage Vout maintains a predetermined voltage level. The controller 50 can include a buffer 51, a resistor R52, a software control section 53, a transformer 54, and the software drive section 55.

[0034] Buffer 51 can, for example, perform impedance conversion and convert a voltage range of the signal supplied by voltage measurement circuit 9 to output a voltage-converted signal. Resistor R52 can serve to eliminate disturbances in the output signal supplied by buffer 51 and / or limiting factors such as surge voltages and overcurrent, in order to protect buffer 51 and computer 69. Based on the signal supplied by buffer 51 through resistor R52, software control section 53 can control software drive section 55 to ensure that the output voltage Vout maintains a predetermined voltage level.More specifically, the SW control section 53 can have the function of generating control signals that serve as the basis signals for the respective SW control signals S11 to S14, and supplying the generated control signals to the SW control section 55 via the transformer 54. The SW control section 55 can generate the SW control signals S11 to S14 based on the control signals supplied by the SW control section 53 via the transformer 54, and supply the generated SW control signals S11 to S14 to the switching elements SW11 to SW14 of the switching circuit 10.

[0035] With this configuration, the switching circuit 10 can perform the switching operation based on the SW control signals S11 to S14, enabling the switching power supply unit 1 to operate in such a way that the output voltage Vout maintains a predetermined voltage level.

[0036] The computer 69 can determine an output current Iout based on the input voltage Vin, the output voltage Vout, and the input current Iin, and output this information. In other words, the switching power supply unit 1 can determine the output current Iout by calculation based on the input voltage Vin, the output voltage Vout, and the input current Iin, without requiring a current-measuring circuit in the secondary high-voltage line L2H to measure the output current Iout.

[0037] The computer 69 can perform calculations based on the measurement signal corresponding to the input current Iin, the measurement signal corresponding to the input voltage Vin, and a voltage related to the output voltage Vout supplied by buffer 51 to determine the output current Iout. For example, the computer 69 can determine a switching duty cycle D based on the input voltage Vin and the output voltage Vout to determine the output current Iout based on the input current Iin and the determined duty cycle D. Furthermore, the computer 69 can supply the information about the input voltage Vin, the output voltage Vout, the input current Iin, and the output current Iout to an external unit connected to terminal T5.The external unit can be, for example, a control unit, but is not limited to, that controls a system as a whole, including the switching power supply unit 1, and collects data on the states of the switching power supply unit 1 (such as input and output voltage, input and output current, and temperature) in order to monitor its state. A non-restrictive example of such a control unit could be a vehicle controller, referred to as an electronic control unit (ECU).

[0038] Computer 69 can be designed using a controller, such as a microcontroller (MCU), but is not limited to this. For example, in addition to Computer 69, the software control section 53, or a part of the software control section 53, can be implemented using a controller, such as a microcomputer, but is not limited to this. [1.2 Operation]

[0039] An overview of the entire operation of the switching power supply unit 1 is now described. The switching circuit 10 can switch the switching components SW11 to SW14 based on the respective SW control signals S11 to S14 in order to convert the DC voltage Vin supplied by the high-voltage battery BH into AC voltage and supply the converted AC voltage across both ends of the primary winding 21 of the transformer 20. The transformer 20 can convert (for example, step down) the AC voltage to an AC voltage that is Ns / Np times smaller than the applied AC voltage and output the voltage-converted AC voltage at the secondary windings 22A and 22B. The rectification circuit 30 can rectify the output AC voltage.The smoothing circuit 40 can smooth the rectified signal to generate the output DC voltage Vout and supply the output voltage Vout to the low-voltage battery BL, which can be coupled between the output terminals T3 and T4.

[0040] The controller 50 can generate the software control signals S11 to S14 based on a measurement of the output voltage Vout derived from the voltage measurement circuit 9 and supply the generated software control signals S11 to S14 to the switching circuit 10 to control the switching circuit 10 in order to maintain the output voltage Vout at a predefined voltage level. The computer 69 can determine the output current Iout based on the input voltage Vin, the output voltage Vout, and the input current Iin and output this information. [2. Coil component (Transformer 20)][2.1 Configuration and implementation]

[0041] This section describes a design example of a coil component with a variable number of turns, which can be applied to transformer 20 (such as an isolation transformer). The coil component can serve as a power supply circuit device in the switching power supply unit 1, which is shown here as an example. Fig. Figure 1 is shown. Here, a design example of a coil component complex is also described, which can include the transformer 20, which serves as a first coil component, and the resonant coil Lr, which serves as a second coil component.

[0042] Fig. Figure 15 shows an example of the design of an existing coil component, which is designed using typical printed coil windings according to a comparative example. The printed coils can have a design in which copper foils, such as those of inner layers of a printed multilayer circuit board 100, which is shown as an example in Fig. Figure 2 shows that the copper foils are wound around subsequently attached magnetic cores or "cores". The copper foils of the respective layers can be coupled to each other by vias 105. The in Fig. The printed multilayer circuit board 100 shown can be a four-layer substrate comprising a first layer 101, a second layer 102, a third layer 103, and a fourth layer 104 from a surface (an upper layer) to a lower layer. The printed multilayer circuit board 100 allows each layer to be electrically connected to every other layer via the via hole 105.

[0043] Fig. Figure 15 shows, according to the comparative example, a coil pattern of a second layer 220 as one of the printed coil windings. The coil pattern of the second layer 220 can be configured to extend around a core 161, which is used for the transformer 20 (such as the isolation transformer), and around a core 162, which is used for the resonant coil Lr. The cores 161 and 162 can be, for example, ferrite cores, but are not limited to this. The coil pattern of the second layer 220, which extends around the core 161, is described in Figure 162. Fig. The core 161 shown in Figure 15 is wound and can form part of the primary winding 21 of the transformer 20. In a DC-DC step-down converter, for potential reasons, the high-voltage primary winding 21 can often be provided as the inner layer, and the low-voltage secondary windings 22A and 22B can often be provided as the outer layers. In the example of the one shown in Figure 15, the core 161 can form part of the primary winding 21 of the transformer 20. Fig. In the four-layer substrate shown in Figure 2, the primary winding 21 can be configured in the second layer 102 and the third layer 103, and the secondary windings 22A and 22B can be configured in the first layer 101 and the fourth layer 104. The coil pattern of the second layer 220 can also include connecting vias 151, 152, and 153 to provide connections to each other layer.

[0044] In the Fig. In the comparative example shown in Figure 15, the coil pattern of the second layer 220, for a portion equivalent to a portion of the primary winding 21 of the transformer 20, has a fixed number of four turns (4 Ts). As can be seen, the number of turns of each printed coil winding is fixed, and it is difficult to easily change the number of turns, especially the number of turns of a winding designed in an inner layer.

[0045] In contrast, the coil element according to the present exemplary embodiment has a design in which the number of turns is variable, as in the Fig. Figures 3 to 6 illustrate coil patterns of such a coil component. As shown in Fig. In the comparative example shown in Figure 15, the primary winding 21 of the transformer 20 can be configured in the second layer 102 and the third layer 103, and the secondary windings 22A and 22B of the transformer 20 can be configured in the first layer 101 and the fourth layer 104, in an exemplary embodiment of the four-layer substrate shown as an example in Fig. 2 is shown. Fig. Figures 3 to 6 each show an example of the design of the coil element complex, which may include the transformer 20, which serves as a first coil element, and the resonant coil Lr, which is electrically coupled to the first coil element and serves as a second coil element.

[0046] An example of a design using the four-layer substrate is described below; however, the number of layers of a substrate on which the coil element is formed according to the present exemplary embodiment is not limited to four layers. Likewise, the arrangement of the coil patterns forming the respective layers and the number of layers for such coil patterns are not limited to those in the design example described below.

[0047] Fig. Figure 3 shows an example of a coil pattern of a first layer 110 structuring the coil element according to an exemplary embodiment of the invention. Fig. Figure 4 shows an example of a coil pattern of a second layer 120, Fig. Figure 5 shows an example of a coil pattern of a third layer 130, and Fig. Figure 6 shows an example of a coil pattern of a fourth layer 140, each of which structures the coil element according to the exemplary embodiment of the invention. The coil patterns of the corresponding layers can be configured to extend around the core 161, which is used for the transformer 20, and around the core 162, which is used for the resonant coil Lr. Each layer can have the connecting vias 151, 152, and 153 to provide connections to each other layer.

[0048] The coil pattern of the second layer 120 and the coil pattern of the third layer 130 can be coupled to each other via the connecting vias 151, forming a winding section equivalent to the primary winding 21 of the transformer 20. The coil pattern of the second layer 120 and the coil pattern of the third layer 130 can also be coupled to each other via the connecting vias 153, forming a winding section equivalent to the resonant coil Lr. The winding section equivalent to the primary winding 21 of the transformer 20 and the winding section equivalent to the resonant coil Lr are coupled to each other via the connecting vias 152.

[0049] In the coil assembly according to the present exemplary embodiment, a variable-turn section 200 can be provided in the section equivalent to the primary winding 21 of the transformer 20, which varies the number of turns. The variable-turn section 200 can have turn selection vias 210. The coil pattern of the second layer 120 comprises a plurality of separate end sections 121. The separate end sections 121 are separated from each other by a gap between them.

[0050] With reference to Fig. 7. In the coil component, a jumper connection 160, as a non-restrictive example of a "conducting element," can be inserted into the turn-selection vias 210 of a surface (of the first layer) of the substrate, thereby making it possible to change the electrical conductivity states of the corresponding separate end sections 121 via the turn-selection vias 210. In other words, the jumper connection 160 allows selective electrical conduction between the corresponding separate end sections 121. The selective electrical conduction causes a change in the number of turns of the coil pattern of the second layer 120.The jumper connection 160 can be provided on the surface layer or on and from the surface layer into the turn-number selection vias 210 to create a conduction bridge between one of the turn-number selection vias 210 in one of the separate end sections 121 and one of the turn-number selection vias 210 in another of the separate end sections 121. The conduction bridge allows selective electrical conduction between the corresponding separate end sections 121. Thus, it is possible to change the turn number of the coil pattern of the second layer 120, as will be described later with reference to the following. Fig. Sections 8 to 10 are described. When the number of turns of the coil pattern of the second layer 120 is changed, all the patterns of the coil pattern of the second layer 120 function as coils, regardless of the change in the number of turns by the conductor element. In other words, each section in the coil pattern 120 forms a part of the coil element, regardless of the number of turns.

[0051] The multitude of separate end sections 121 can be provided between the transformer 20, which serves as the first coil element, and the resonant coil Lr, which serves as the second coil element.

[0052] The coil pattern of the second layer 120 can have three or more turn-number selection vias 210 in a turn-number variable region Ta of the coil pattern of the second layer 120. In other words, the separate end sections 121 as a whole have three or more turn-number selection vias 210. Preferably, the adjacent turn-number selection vias 210 can be provided at substantially regular intervals.

[0053] In the variable-turn region Ta of the second-layer coil pattern 120, a starting portion of a turn of the pattern, or a "separate turn start-end section," and a ending portion of the turn of the pattern, or a "separate turn end-end section," can each have a turn-selection via 210. In other words, in the variable-turn region Ta, the separate turn start-end section of the second-layer coil pattern 120 can be configured with a turn-selection via 211, and the separate turn end-end section of the second-layer coil pattern 120 can be configured with a turn-selection via 212, as shown in Fig. 4 shown. In the variable number of turns region Ta, one or more parts of the separate end sections 121, which are not the separate turn start end section and the separate turn end end section, can also be formed with the plurality (two or more) of turn number selection via holes.

[0054] Fig. Figure 7 illustrates an example of the assembly of cores 161 and 162 and jumper terminal 160. To use the coil assembly as an isolation transformer, jumper terminal 160 can be coupled based on the arrangement of the turn selection vias 210. With reference to Fig. 7. The jumper terminal 160 can be mounted on the surface layer of the substrate, after which, for example, the layers from the first layer to the fourth layer can be exposed to a solder joint. The jumper terminal 160 can preferably be mounted using automated assembly, although the jumper terminal 160 does not restrict the mounting method. A large current flows even on the primary side of the vehicle DC-DC converter, and thus a combination of a metal jumper and solder mounting allows for a greater increase in current tolerance than in a case where the vias are used alone.

[0055] Likewise, with regard to manufacturing and testing, the surface layer of the substrate can be marked with any symbol using screen printing or any other suitable printing process to indicate into which turn number selection via holes 210 the jumper connector 160 should be inserted to configure the intended number of turns.

[0056] The Fig. Figures 8 to 10 illustrate some examples of the connection arrangement of jumper terminal 160 when the number of turns is changed in a range from four turns to six turns. Fig. Figure 8 illustrates a connection in the coil pattern of the second layer 120 in an example where the number of turns is selected to be four turns. Fig. Figure 9 illustrates a connection in the coil pattern of the second layer 120 in an example where the number of turns is selected to be five turns. Fig. Figure 10 illustrates a connection in the coil pattern of the second layer 120 in an example where the number of turns is selected to be six turns.

[0057] With regard to the Fig. 8 to 10 are sections of the turn-number selection via holes 210, which are connected by thick black lines, equivalent to connection positions 201 of the jumper terminal 160, where the electrical connection is made. In the example with four windings, as in Fig. Figure 8 illustrates that patterns 171, integrated via jumper connection 160, are partially formed. Similarly, in the example with five windings, as shown in Fig. Figure 9 illustrates patterns 172, which are partially formed through the jumper terminal 160. Thus, all of the patterns in the coil pattern of the second layer 120 serve as a coil, regardless of changes in the number of turns, without wasting any patterns. The intervals or "spacings" of the turn-number selection vias 210, to which the jumper terminals 160 are to be coupled, can be made essentially the same size to allow the use of a single type of jumper terminal 160.

[0058] In the coil assembly according to the present exemplary embodiment, the variable number of turns range 200 can be provided for varying the number of turns between the transformer 20, which serves as the first coil assembly, and the resonant coil Lr, which serves as the second coil assembly. Thus, it is possible to change the number of turns without affecting the winding in any other layer. [Examples of connections for which jumper pin 160 is not used]

[0059] Fig. Figure 7 illustrates an example of selecting the number of turns using the conductive jumper terminal 160. Alternatively, bidirectional switching devices can be used to select the number of turns. These switching devices can be, for example, semiconductor relays, but are not limited to them.

[0060] Fig. Figure 11 illustrates an example of a configuration in which the selection of the number of turns of the coil pattern of the second layer 120 is performed using switching devices 163. The switching devices 163 can be provided between the turn-selection vias 210 in the surface layer (the first layer) of the substrate, allowing the electrical conduction states of the corresponding adjacent turn-selection vias 210 to be changed. A microcomputer or any other suitable computer can be used to select the number of turns as required. In this case, the number of turns can be selected, for example, according to a change in the input voltage Vin to achieve optimal operation (or to achieve maximum efficiency). In an example of the configuration shown in Figure 11, the number of turns is selected according to a change in the input voltage Vin to achieve optimal operation (or to achieve maximum efficiency). Fig. In the DC-DC converter shown in Figure 1, the turns controller 5 can control the number of turns Np of the primary winding 21 of the transformer 20 according to the input voltage Vin. The number of turns can be reduced when the input voltage Vin decreases, allowing the DC-DC converter to operate to its limit even when the vehicle's high-voltage battery is discharged. Thus, it is possible to contribute to extending the vehicle's range when an embodiment of the invention is applied to a vehicle, such as an electric vehicle, but this application is not limited to such vehicles.

[0061] The coil element, according to the exemplary embodiment, also allows the number of turns of the coil pattern of the second layer 120 to be varied in a range of, for example, four to six turns, but not limited thereto, as shown in the example in the Fig. Figures 8 to 10 are shown. For example, if the number of turns in the winding in the third layer, which is equivalent to the primary winding 21 of transformer 20, is six turns, it is possible to make the number of turns of the primary winding 21 of transformer 20 variable from 10 to 12 turns as a whole. Thus, it is possible to support two types of HV batteries, whose respective voltages are in the range of 200 V to 300 V and 300 V to 400 V, as shown in the example in Fig. 16 shown.

[0062] Fig. Figure 12 illustrates an example of a configuration where the selection of the number of turns of the coil pattern is carried out using connecting conductors 164. The connecting conductors 164 can be, for example, conductor patterns, but are not limited to them. With reference to Fig. 12 The multitude of turn-number selection via holes 210 in the surface layer (the first layer) of the substrate can be brought into electrical conduction with each other by the conductor pattern of the connecting conductors 164. Each pattern of the connecting conductor 164 can be cut with a laser cutter or in any other suitable way according to the number of turns to be selected, which allows the selection of the desired number of turns. [2.2 Effect]

[0063] According to the exemplary embodiment described above, the separate end sections 121 are selectively electrically connected to each other to change the number of turns of the coil pattern of the second layer 120. When changing the number of turns of the coil pattern of the second layer 120, each section in the coil pattern of the second layer 120 forms a part of the coil element, regardless of the number of turns. Therefore, it is possible to easily vary the number of turns without having to fabricate a large number of substrates or creating a wasted pattern, regardless of the change in the number of turns. It is also possible to increase the efficiency of a power supply component and improve power supply resources.

[0064] The use of the coil component according to the present exemplary embodiment makes it possible to configure the transformer with different numbers of turns and to use a single type of substrate. Thus, it is possible to support different input voltage ranges with a single type of substrate, thereby achieving factors such as the shared use of a single substrate, resulting in cost reduction and a reduced amount of design effort, but not limited to these.

[0065] The coil assembly according to the present exemplary embodiment can be used as a power supply circuit device of a DC-DC converter, which is used in an electric vehicle, such as a HEV, but not limited to. The present exemplary embodiment of the invention uses only a single-type patterned printed coil substrate and thus does not include a variety of coil winding types as components. Furthermore, only one layer can be subjected to changes in the turns ratio, which allows for a small number of changes to the transformer parameters. The windings can be connected in series, parallel, or a combination of both, which makes it possible to prevent the occurrence of wasted patterns.In an embodiment in which the jumper terminal 160 is used, the combination of the metal jumper terminal 160 with the solder connection (embedding) allows an increase in current tolerance including the use of the via holes. [Comparison between the embodiment of the invention and the prior art]

[0066] JP-H08-69935A proposes manufacturing a variety of coil types, differing in the number of turns on a component forming a printed coil, to vary the overall number of turns of the coil by combining these multiple coil types. This necessitates manufacturing a variety of coil substrate types, also differing in the number of turns, and incorporating a process step to join these substrate types. Consequently, a variety of coil substrate body types are required, thus moving away from configurations using the same substrate.In contrast, the present exemplary embodiment uses the patterns previously provided on the substrate and changes the number of turns by changing the connection of such patterns, and thus, unlike JP H08 - 69 935 A, does not involve the manufacture of a variety of types of coil windings as components.

[0067] JP H09-92537A selects and uses patterns previously arranged on a substrate surface to tune a coil. JP H09-92537A has the disadvantage that unused patterns are wasted, thus preventing effective use of the substrate area. In contrast, in the present exemplary embodiment, the patterns can be connected in series, parallel, or a combination of both, which makes it possible to prevent wasted patterns and effectively utilize the substrate area.

[0068] JP 3 223 425 B divides adjacent patterns arranged on a substrate surface into two groups: a primary winding pattern and a secondary winding pattern. It then selects the two groups to combine patterns, thereby reducing the coupling capacitance. However, this increases the leakage inductance and correspondingly reduces the transformer's efficiency. In contrast, the present exemplary embodiment changes only the number of turns in the primary winding 21, specifically altering the ratio of the number of turns in the primary winding 21 to the number of turns in the secondary windings 22A and 22B. This allows the coupling capacitance between the primary and secondary sides to remain constant and also enables the transformer's leakage inductance to be fixed at a low value, resulting in a stable design.JP 3 223 425 B also describes how the connection of the patterns can be changed on different surfaces to vary the ratio of the number of turns in the transformer. The present exemplary embodiment differs from JP 3 223 425 B in that the change in the connection of the patterns to change the ratio of the number of turns is only carried out on the same single surface.

[0069] JP2013 - 26 556 A manufactures a plurality of substrates, each requiring the formation of a printed coil, and stacks these substrates to produce coil windings. During manufacturing, the connection method of the windings, based on a jumper resistor, etc., is modified to vary the number of turns in the stacked coil windings. In contrast, in the present exemplary embodiment, the number of turns is changed by modifying the connection of the patterns arranged in only one of the layers of the individual substrate, without stacking the plurality of substrates, thus eliminating the need to manufacture and stack the plurality of substrates.

[0070] In JP H03-183 106 A, a metal pin is inserted into via holes and soldered to enhance the mechanical coupling of a multitude of substrates. In contrast, in the present exemplary embodiment, the jumper connection and solder joint are used solely for the purpose of changing the number of turns by altering the connection of the coil patterns arranged in only one of the layers of the single substrate, and for increasing the current tolerance of the via holes. It differs from JP H03-183 106 A in that the present exemplary embodiment does not aim to change the strength of the mechanical coupling. [3. Modification example of the coil component]

[0071] The exemplary embodiment described above illustrates a configuration where the number of turns in the coil pattern of the second layer is changed to 120. Alternatively, the number of turns in the coil pattern can be varied in any other layer.

[0072] With regard to the Fig. 13 and Fig. 14 For example, both the number of turns of a coil pattern of a second layer 120A and the number of turns of a coil pattern of a third layer 130A, which are equivalent to the primary winding 21 of the transformer 20, can be made variable. Fig. Figure 13 shows an example of the coil pattern of the second layer 120A in the coil component according to the present modification example. Fig. Figure 14 shows an example of the coil pattern of the third layer 130A in the coil component according to the present modification example.

[0073] In the coil pattern of the second layer 120A, a section equivalent to the primary winding 21 of the transformer 20 can be provided with the variable number of turns section 200, which varies the number of turns as in the exemplary embodiment described above.

[0074] In the third-layer coil pattern 130A, a section equivalent to the primary winding 21 of the transformer 20 may be provided with the variable-turns section 300, which varies the number of turns as in the second-layer coil pattern 120A. The variable-turns section 300 may have turn-selection vias 310. The third-layer coil pattern 130A comprises a plurality of separate end sections 131. The separate end sections 131 are separated from each other by a gap between them.

[0075] In the coil assembly according to the present modification example, the jumper connection 160 can be inserted, as a non-restrictive example of a “conducting element”, into the turn selection via holes 210 of the surface layer (of the first layer) of the substrate, as in the exemplary embodiment shown as an example in Fig. 7, which makes it possible to change the electrical conductivity states of the corresponding separate end sections 131 of the third layer coil pattern 130A via the turn selection vias 310. Thus, it is possible to change the turn count of the third layer coil pattern 130A, as described in the Fig. The exemplary embodiment described in Figures 8 to 10. When the number of turns of the coil pattern of the third layer 130A is changed, all of the patterns of the coil pattern of the third layer 130A serve as coils, regardless of the change in the number of turns by the conductor element.

[0076] The coil pattern of the third layer 130A can have three or more turn-number selection vias 310 in a turn-number variable region Tb of the coil pattern of the third layer 130A. In other words, the plurality of separate end sections 131 as a whole has three or more turn-number selection vias 310. Preferably, the adjacent turn-number selection vias 310 can be provided at substantially regular intervals.

[0077] In the variable-turn region Tb of the third-layer coil pattern 130A, the separate turn start-end section and the separate turn end-end section of the pattern can each have only one turn selection via 310. In other words, in the variable-turn region Tb, the separate turn start-end section of the third-layer coil pattern 130A can be configured with a turn selection via 311, and the separate turn end-end section of the third-layer coil pattern 130A can be configured with a turn selection via 312, as shown in Fig.14 shown. In the variable turn number area Tb, one or more parts of the separate end sections 131, which are not the separate turn start end section and the separate turn end end section, can also be formed with the plurality (two or more) of turn number selection via holes. [4. Other embodiments]

[0078] Although the invention has been described above as an example with reference to the exemplary embodiments and the examples of modification, the technology of the invention is not limited to this, but can be modified in many ways.

[0079] For example, the exemplary embodiments and the modification examples describe an example in which the coil element is applied to a power supply circuit device. However, according to the exemplary embodiments and the modification examples, the coil element, the coil element complex, and the transformer are each applicable to any device in addition to the power supply circuit device. Furthermore, according to the exemplary embodiments and the modification examples of the invention, the coil element is applicable to any device, such as a coil, in addition to the transformer, without being limited to such devices.

[0080] It is possible to obtain at least the following configurations from the exemplary embodiments described above and the modification examples of the disclosure. (1) Coil assembly, not claimed, comprising: a coil pattern provided on a substrate and comprising a plurality of separate end sections, the separate end sections being separated by a gap between them; and a conduction element that allows selective electrical conduction between the separated end sections, wherein the selective electrical conduction causes a change in the number of turns of the coil pattern, wherein Each section in the coil pattern shapes a part of the coil element, regardless of the number of turns. (2) coil component according to (1), wherein the substrate comprises a multi-layered substrate consisting of a surface layer and one or more internal layers, the coil pattern is provided in one or more of the inner layers of the multilayer substrate, Each of the multiple separate end sections has one or more turn-number selection via holes, and the conductor element is suitable for use on the surface layer or on and from the Surface layer provided in the turn selection via holes to create a conduction bridge between one of the turn selection via holes in one of the separated end sections and one of the turn selection via holes in another of the separated end sections, wherein the conduction bridge allows selective electrical conduction between the respective separated end sections. (3) coil component according to (2), wherein the multitude of separate end sections includes a separate winding start end section and a separate winding end end section, Each of the separate winding start-end section and the separate winding end-end section has a winding number selection via hole, and one or more of the separate end sections, which are not both the separate turn start end section and the separate turn end end section, have two or more turn number selection via holes. (4) Coil assembly according to (2) or (3), wherein the plurality of separate end sections as a whole has three or more turn selection vias that are adjacent at substantially regular intervals. (5) Transformer, not claimed, comprising: a primary winding; and a secondary winding including the primary winding or the secondary winding: a coil pattern provided on a substrate and comprising a plurality of separate end sections, the separate end sections being separated by a gap between them; and a conduction element that allows selective electrical conduction between the respective separated end sections, wherein the selective electrical conduction causes a change in the number of turns of the coil pattern, wherein Each section in the coil pattern shapes a part of the coil element, regardless of the number of turns. (6) Coil assembly complex, not claimed, comprising: a first coil component; and a second coil element that is electrically coupled to the first coil element, the first coil component comprises: a coil pattern provided on a substrate and comprising a plurality of separate end sections, the separate end sections being separated by a gap between them; and a conduction element that allows selective electrical conduction between the respective separated end sections, wherein the selective electrical conduction causes a change in the number of turns of the coil pattern, wherein Each section in the coil pattern shapes a part of the coil element, regardless of the number of turns. (7) Coil element complex according to (6) wherein the separate end sections between the first coil element and the second coil element are provided on the substrate. (8) Power supply unit, not claimed, comprising a power supply circuit device designed by a coil element, the coil component includes: a coil pattern provided on a substrate and comprising a plurality of separate end sections, the separate end sections being separated by a gap between them; and a conduction element that allows selective electrical conduction between the respective separated end sections, wherein the selective electrical conduction causes a change in the number of turns of the coil pattern, wherein Each section in the coil pattern shapes a part of the coil element, regardless of the number of turns. (9) Power supply unit according to (8), further comprising a turns controller, wherein the conductor element includes a switching device, and The number of turns controller is designed to control the switching of the switching device in order to control the number of turns. (10) Power supply unit according to (9) wherein the turns controller controls the number of turns based on a magnitude of an input voltage.

Claims

[1] Coil assembly, comprising: a coil pattern (110, 120, 130, 140, 120A, 130A, 220) arranged on a substrate and comprising a plurality of separate end sections (121, 131), wherein the separate end sections (121, 131) are separated by a gap between them; and a conduction element (160) that allows selective electrical conduction between the respective separated end sections (121, 131), wherein the selective electrical conduction causes a change in the number of turns of the coil pattern (110, 120, 130, 140, 120A, 130A, 220), wherein Each of the separate end sections (121, 131) in the coil pattern (110, 120, 130, 140, 120A, 130A, 220) forms a part of the coil element, regardless of the number of turns, wherein the substrate comprises a multilayer substrate comprising a surface layer (101) and one or more internal layers (102, 103), the coil pattern (110, 120, 130, 140, 120A, 130A, 220) is arranged in one or more of the inner layers (102, 103) of the multilayer substrate, each of the multiple separate end sections (121, 131) has one or more turn-number selection via holes (210, 211, 212, 310, 311, 312), the multitude of separate end sections (121, 131) includes a separate winding start end section and a separate winding end end section, Each of the separate winding start-end section and the separate winding end-end section has a winding number selection via hole, and one or more of the separate end sections (121, 131) that are neither the separate turn start end section nor the separate turn end end section, have two or more turn number selection via holes (210, 211, 212, 310, 311, 312), wherein the conducting element (160) is arranged on the surface layer (101) or on and from the surface layer (101) into the turn selection via holes (210, 211, 212, 310, 311, 312) to create a conducting bridge between one of the turn selection via holes (210, 211, 212, 310, 311, 312) in one of the separated end sections (121, 131) and one of the turn selection via holes (210, 211, 212, 310, 311, 312) in another of the separated end sections (121, 131), wherein the conducting bridge allows selective electrical conduction between the respective separated end sections (121, 131). [2] Coil element according to claim 1, wherein the plurality of separate end sections (121, 131) as a whole has three or more turn selection via holes (210, 211, 212, 310, 311, 312) that are adjacent at regular intervals. [3] Coil element according to claim 1, wherein the plurality of separate end sections (121, 131) as a whole has three or more turn selection via holes (210, 211, 212, 310, 311, 312) that are adjacent at regular intervals. [4] Transformer (20), comprising: a primary winding (21); and a secondary winding (22A, 22B), comprising the primary winding (21) or the secondary winding (22A, 22B): a coil pattern (110, 120, 130, 140, 120A, 130A, 220) arranged on a substrate and comprising a plurality of separate end sections (121, 131), wherein the separate end sections (121, 131) are separated by a gap between them; and a conduction element (160) that allows selective electrical conduction between the respective separated end sections (121, 131), wherein the selective electrical conduction causes a change in the number of turns of the coil pattern (110, 120, 130, 140, 120A, 130A, 220), wherein Each of the separate end sections (121, 131) in the coil pattern (110, 120, 130, 140, 120A, 130A, 220) forms a part of a coil element, regardless of the number of turns, wherein the substrate comprises a multilayer substrate comprising a surface layer (101) and one or more internal layers (102, 103), the coil pattern (110, 120, 130, 140, 120A, 130A, 220) is arranged in one or more of the inner layers (102, 103) of the multilayer substrate, each of the multiple separate end sections (121, 131) has one or more turn-number selection via holes (210, 211, 212, 310, 311, 312), the multitude of separate end sections (121, 131) includes a separate winding start end section and a separate winding end end section, Each of the separate winding start end section and the separate winding end end section has a winding number selection via hole (210, 211, 212, 310, 311, 312), and one or more of the separate end sections (121, 131) that are neither the separate turn start end section nor the separate turn end end section, have two or more turn number selection via holes (210, 211, 212, 310, 311, 312), wherein the conducting element (160) is arranged on the surface layer (101) or on and from the surface layer (101) into the turn selection via holes (210, 211, 212, 310, 311, 312) to create a conducting bridge between one of the turn selection via holes (210, 211, 212, 310, 311, 312) in one of the separated end sections (121, 131) and one of the turn selection via holes (210, 211, 212, 310, 311, 312) in another of the separated end sections (121, 131), wherein the conducting bridge allows selective electrical conduction between the respective separated end sections (121, 131). [5] Coil assembly complex comprising: a first coil component; and a second coil element that is electrically coupled to the first coil element, the first coil component comprises: a coil pattern (110, 120, 130, 140, 120A, 130A, 220) arranged on a substrate and comprising a plurality of separate end sections (121, 131), wherein the separate end sections (121, 131) are separated by a gap between them; and a conduction element (160) that allows selective electrical conduction between the respective separated end sections (121, 131), wherein the selective electrical conduction causes a change in the number of turns of the coil pattern (110, 120, 130, 140, 120A, 130A, 220), wherein Each of the separate end sections (121, 131) in the coil pattern (110, 120, 130, 140, 120A, 130A, 220) forms a part of the first coil element, regardless of the number of turns, wherein separate end sections (121, 131) are arranged between the first coil element and the second coil element on the substrate. [6] Power supply unit (1), comprising a power supply circuit device designed by a coil element, the coil component includes: a coil pattern (110, 120, 130, 140, 120A, 130A, 220) arranged on a substrate and comprising a plurality of separate end sections (121, 131), wherein the separate end sections (121, 131) are separated by a gap between them; and a conduction element (160) that allows selective electrical conduction between the respective separated end sections (121, 131), wherein the selective electrical conduction causes a change in the number of turns of the coil pattern (110, 120, 130, 140, 120A, 130A, 220), wherein Each of the separate end sections (121, 131) in the coil pattern (110, 120, 130, 140, 120A, 130A, 220) forms a part of the coil element, regardless of the number of turns, wherein the substrate comprises a multilayer substrate comprising a surface layer (101) and one or more internal layers (102, 103), the coil pattern (110, 120, 130, 140, 120A, 130A, 220) is arranged in one or more of the inner layers (102, 103) of the multilayer substrate, each of the multiple separate end sections (121, 131) has one or more turn-number selection via holes (210, 211, 212, 310, 311, 312), the multitude of separate end sections (121, 131) includes a separate winding start end section and a separate winding end end section, Each of the separate winding start-end section and the separate winding end-end section has a winding number selection via hole, and one or more of the separate end sections (121, 131) that are neither the separate turn start end section nor the separate turn end end section, have two or more turn number selection via holes (210, 211, 212, 310, 311, 312), wherein the conducting element (160) is arranged on the surface layer (101) or on and from the surface layer (101) into the turn selection via holes (210, 211, 212, 310, 311, 312) to create a conducting bridge between one of the turn selection via holes (210, 211, 212, 310, 311, 312) in one of the separated end sections (121, 131) and one of the turn selection via holes (210, 211, 212, 310, 311, 312) in another of the separated end sections (121, 131), wherein the conducting bridge allows selective electrical conduction between the respective separated end sections (121, 131). [7] Power supply unit (1) according to claim 6, further comprising a turns controller (5), wherein the conductor element (160) comprises a switching device (163), and the number of turns controller (5) is designed to control the switching of the switching device (163) in order to control the number of turns. [8] Power supply unit (1) according to claim 6, wherein the turns controller (5) controls the number of turns based on the magnitude of an input voltage.

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