Heat preservation circuit of power battery, vehicle high-voltage circuit and vehicle

Abstract

The application discloses a heat preservation circuit of a power battery, a high-voltage circuit of a vehicle and the vehicle. The heat preservation circuit of the power battery comprises a heater, a vehicle-mounted charger and a first external power source. The heater is arranged corresponding to the power battery. The vehicle-mounted charger is connected with the first external power source, the power battery and the heater respectively. In a non-charging scene, the vehicle-mounted charger supplies power to the heater based on the electric energy of the power battery, so that the heater preserves the power battery. In a charging scene, the vehicle-mounted charger supplies power to the heater based on the electric energy provided by the first external power source, so that the heater preserves the power battery. The heat preservation circuit of the application optimizes the high-voltage architecture of the vehicle, so that the heater no longer directly parallelly takes power from other high-voltage components, thereby reducing the energy consumption and prolonging the service life of the high-voltage components.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a power battery insulation circuit, a vehicle high-voltage circuit, and a vehicle. Background Technology

[0002] The low-temperature performance of power batteries limits the sales area of ​​electric vehicles. To address this, insulation designs for power batteries have emerged. Common insulation functions include passive insulation, active insulation, and charging insulation.

[0003] One scenario for heat preservation is AC charging socket heat preservation. This refers to the practice of using a home charging station to keep the battery warm after charging is complete. Instead of using the battery's own charge, the onboard charger converts AC grid energy into DC power to supply the onboard heater. This function can be set or scheduled to be activated in the vehicle's infotainment system or mobile phone, allowing the electric vehicle to operate at its best performance under suitable battery pack temperatures, thus alleviating range anxiety in low temperatures.

[0004] In related technologies, the high-voltage architecture of a vehicle directly connects the heater and various high-voltage components in parallel as loads for the power battery. However, during the AC charging gun insulation process, heating the heater requires all high-voltage components on the vehicle to operate at high voltage, resulting in poor energy consumption and potential damage to high-voltage components under abnormal conditions, thus shortening their lifespan. Summary of the Invention

[0005] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, the first objective of this invention is to propose a thermal insulation circuit for a power battery. By innovatively optimizing the high-voltage architecture of the vehicle, the heater no longer needs to be directly connected in parallel with other high-voltage components for power, thereby reducing energy consumption and extending the service life of the high-voltage components.

[0006] The second objective of this invention is to provide a high-voltage circuit for vehicles.

[0007] The third objective of this invention is to provide a vehicle.

[0008] To achieve the above objectives, a first aspect of the present invention provides a heat preservation circuit for a power battery, comprising: a heater, the heater being disposed corresponding to the power battery; an on-board charger, the on-board charger being connected to a first external power source, the power battery, and the heater, for supplying power to the heater based on the electrical energy of the power battery in a non-charging scenario, so that the heater keeps the power battery warm; and, in a charging scenario, supplying power to the heater based on the electrical energy provided by the first external power source, so that the heater keeps the power battery warm.

[0009] According to an embodiment of the present invention, the heat preservation circuit for a power battery supplies power to the heater based on the electrical energy of the power battery in a non-charging scenario, so that the heater can keep the power battery warm; in a charging scenario, it supplies power to the heater based on the electrical energy provided by a first external power source, so that the heater can keep the power battery warm. Thus, this circuit, through innovative optimization of the vehicle's high-voltage architecture, eliminates the need for the heater to be directly connected in parallel with other high-voltage components for power, thereby reducing energy consumption and extending the service life of high-voltage components.

[0010] In addition, the heat preservation circuit of the power battery according to the above embodiments of the present invention may also have the following additional technical features:

[0011] According to one embodiment of the present invention, the on-board charger includes a PFC (Power Factor Correction Circuit) circuit and a first DC-DC (Direct Current to Direct Current) conversion circuit. One end of the PFC circuit is connected to a first external power source, and the other end of the PFC circuit is connected to the heater and one end of the first DC-DC conversion circuit via a first DC bus. The other end of the first DC-DC conversion circuit is connected to the power battery via a second DC bus. In the non-charging scenario, the first DC-DC conversion circuit supplies power to the heater based on the electrical energy from the power battery; in the charging scenario, the PFC circuit supplies power to the heater based on the electrical energy provided by the first external power source.

[0012] According to one embodiment of the present invention, the heater includes a heating element and a heating switch, wherein the heating element and the heating switch are connected in series between the positive and negative terminals of the first DC bus.

[0013] According to one embodiment of the present invention, the heating element is a PTC (Positive Temperature Coefficient); and / or, the heating switch is a power switching transistor; and / or, the first external power supply is an AC power supply.

[0014] According to one embodiment of the present invention, the PFC circuit is an interleaved PFC circuit.

[0015] According to one embodiment of the present invention, the first DC-DC conversion circuit is an LLC (Inductor-Inductor-Capacitor) resonant circuit or a CLLC (Capacitor-Inductor-Capacitor-Inductor) resonant circuit.

[0016] According to one embodiment of the present invention, the on-board charger is further configured to charge the power battery based on electrical energy provided by the first external power source in the charging scenario.

[0017] According to one embodiment of the present invention, a pre-charging circuit is further provided between the on-board charger and the power battery for pre-charging the power battery before charging the power battery.

[0018] To achieve the above objectives, a second aspect of the present invention provides a vehicle high-voltage circuit, including the aforementioned heat preservation circuit.

[0019] According to the vehicle high-voltage circuit of the present invention, the above-mentioned heat preservation circuit can reduce energy consumption and extend the service life of high-voltage components.

[0020] To achieve the above objectives, a third aspect of the present invention provides a vehicle including the above-described heat preservation circuit or the above-described vehicle high-voltage circuit.

[0021] According to embodiments of the present invention, the vehicle's high-voltage circuit or insulation circuit described above can reduce energy consumption and extend the service life of high-voltage components.

[0022] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0023] Figure 1 This is a block diagram of the heat preservation circuit of a power battery according to an embodiment of the present invention.

[0024] Figure 2 This is a block diagram of a heat preservation circuit for a power battery according to an embodiment of the present invention.

[0025] Figure 3 This is a hardware topology diagram of a power battery heat preservation circuit according to an embodiment of the present invention;

[0026] Figure 4 This is a block diagram of a heat preservation circuit for a power battery according to an embodiment of the present invention.

[0027] Figure 5 This is a block diagram of a vehicle high-voltage circuit according to an embodiment of the present invention;

[0028] Figure 6 A schematic block diagram of a vehicle according to an embodiment of the present invention;

[0029] Figure 7 This is a block diagram of a vehicle according to another embodiment of the present invention. Detailed Implementation

[0030] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0031] The following description, with reference to the accompanying drawings, illustrates the thermal insulation circuit for the power battery, the high-voltage circuit for the vehicle, and the vehicle as proposed in embodiments of the present invention.

[0032] Figure 1 This is a block diagram of the heat preservation circuit of a power battery according to an embodiment of the present invention.

[0033] like Figure 1 As shown, the heat preservation circuit 100 of the power battery in this embodiment of the invention includes: a heater 110 and an on-board charger 120.

[0034] The heater 110 is configured to correspond to the power battery. The on-board charger 120 is connected to the first external power source, the power battery, and the heater 110. In non-charging scenarios, the charger 120 supplies power to the heater 110 based on the electrical energy of the power battery so that the heater 110 can keep the power battery warm. In charging scenarios, the charger 120 supplies power to the heater 110 based on the electrical energy provided by the first external power source so that the heater 110 can keep the power battery warm.

[0035] Specifically, when the vehicle is not charging or is in motion, the power battery provides DC power to the on-board charger 120. The on-board charger 120 performs DC-DC conversion on the power battery, converting the DC power into a voltage and current suitable for supplying power to the heater 110, thereby generating heat in the heater 110 to heat and maintain the temperature of the power battery. When the vehicle is charging using a first external power source, the on-board charger 120 can deliver the electrical energy provided by the first external power source to the heater 110, causing the heater 110 to generate heat, thereby heating and maintaining the temperature of the power battery. It should be understood that when the electrical energy provided by the first external power source is DC, the on-board charger 120 can perform DC-DC conversion on the electrical energy of the first external power source, converting the DC into voltage and current suitable for powering the heater 110; when the electrical energy provided by the first external power source is AC, the on-board charger 120 can perform AC-DC conversion on the electrical energy of the first external power source, converting the DC into voltage and current suitable for powering the heater 110, so that the heater 110 generates heat, thereby heating and keeping the power battery warm.

[0036] Furthermore, during the operation of the on-board charger 120, when an abnormally high voltage occurs on the bus, the heater 110 can be turned on to consume energy and protect the corresponding high-voltage devices on the bus, such as the bus capacitor and power switching transistor.

[0037] According to one embodiment of the present invention, such as Figure 2 As shown, the on-board charger 120 includes a PFC circuit 121 and a first DC-DC converter circuit 122. One end of the PFC circuit 121 is connected to a first external power source, and the other end of the PFC circuit 121 is connected to the heater 110 and one end of the first DC-DC converter circuit 122 via a first DC bus. The other end of the first DC-DC converter circuit 122 is connected to the power battery via a second DC bus. In non-charging scenarios, the first DC-DC converter circuit 122 supplies power to the heater 110 based on the power battery's electrical energy. In charging scenarios, the PFC circuit 121 supplies power to the heater 110 based on the electrical energy provided by the first external power source.

[0038] Specifically, when the vehicle is not charging or is in motion, the power battery delivers DC power to the first DC-DC conversion circuit 122 through the second DC bus. The first DC-DC conversion circuit 122 converts the power battery's electrical energy into DC power, converting the DC power into a voltage and current suitable for supplying power to the heater 110, so that the heater 110 generates heat, thereby heating and keeping the power battery warm.

[0039] When the vehicle is charged using a first external power source, the first external power source delivers electrical energy to the PFC circuit 121. The PFC circuit 121 converts the AC power supplied by the first external power source into DC power through an AC-DC converter, converting it into a voltage and current suitable for supplying power to the heater 110, thereby generating heat in the heater 110 to heat and maintain the temperature of the power battery. Furthermore, during the conversion process, the PFC circuit 121 can adjust the AC input voltage from the first external power source, adjusting the phase and magnitude of the input current to synchronize it with the input voltage, achieving a sinusoidal current waveform, reducing harmonic distortion, improving the overall power factor of the system, and reducing ineffective reactive power.

[0040] According to one embodiment of the present invention, such as Figure 2 As shown, the heater 110 includes a heating element 111 and a heating switch 112, which are connected in series between the positive and negative terminals of the first DC bus.

[0041] Specifically, when electrical energy is delivered to the heater 110, the on / off state of the heating switch 112 can control the heating element 111 to heat the power battery. When the heating switch 112 is on, the heating element 111 generates heat to heat the power battery; when the heating switch 112 is off, the heating element 111 stops generating heat and no longer heats the power battery.

[0042] According to one embodiment of the present invention, the heating element 111 is a PTC; and / or, the heating switch 112 is a power switch transistor; and / or, the first external power supply is an AC power supply.

[0043] In other words, the power battery can be heated by the PTC, and the switching function can be achieved by controlling the on and off of the power switching transistor. The first external power supply outputs AC power to the on-board charger 120.

[0044] According to one embodiment of the present invention, such as Figure 3 As shown, PFC circuit 121 is an interleaved PFC circuit.

[0045] According to one embodiment of the present invention, the first DC-DC conversion circuit 122 is an LLC resonant circuit or a CLLC resonant circuit. The following describes... Figure 3 The CLLC resonant circuit shown is used as an example for explanation.

[0046] Specifically, when the on-board charger 120 is a single-phase charger, the PFC circuit 121 includes three bridge arms and two PFC inductors L1. One end of each PFC inductor L1 is connected to the midpoint of the first bridge arm and the second bridge arm, respectively. The other end of each PFC inductor L1 is connected to the first terminal of the external power supply, and the second terminal of the external power supply is connected to the midpoint of the third bridge arm. The first bridge arm includes series-connected switches M1 and M2, the second bridge arm includes series-connected switches M3 and M4, and the third bridge arm includes series-connected switches M5 and M6.

[0047] Furthermore, the first DC-DC conversion circuit 122 includes a primary-side switching circuit, a voltage conversion circuit, and a secondary-side switching circuit. The primary-side switching circuit is connected to the primary side of the PFC circuit 121 and the voltage conversion circuit, respectively, and the secondary-side switching circuit is connected to the secondary side of the voltage conversion circuit and the power battery, respectively. The primary-side switching circuit includes switching transistors M7, M8, M9, and M10; the secondary-side switching circuit includes switching transistors M11, M12, M13, and M14; and the voltage conversion circuit includes a first resonant inductor L2, a first resonant capacitor C2, a first transformer T1, a second resonant inductor L3, and a second resonant capacitor C3. The first resonant inductor L2 is connected in series between the first output terminal of the primary-side switching circuit and one end of the primary winding of the first transformer T1; the first resonant capacitor C2 is connected in series between the second output terminal of the primary-side switching circuit and the other end of the primary winding of the first transformer T1; the second resonant inductor L3 is connected in series between the first input terminal of the secondary-side switching circuit and one end of the secondary winding of the first transformer T1; and the second resonant capacitor C3 is connected in series between the second input terminal of the secondary-side switching circuit and one end of the secondary winding of the first transformer T1.

[0048] When the vehicle is not charging or is in motion, the power battery delivers DC power to the first DC-DC converter circuit 122 via the second DC bus. The output current is regulated by adjusting the switching frequency of the switching transistors M11-M14 in the secondary-side switching circuit. The power is transferred to the primary-side switching circuit via the second resonant inductor L3, the second resonant capacitor C3, the first transformer T1, the first resonant inductor L2, and the first resonant capacitor C2. The switching transistors M7-M10 in the primary-side switching circuit act as rectifier output transistors to rectify the power energy into voltage and current levels suitable for supplying power to the heater 110, thereby generating heat in the heater 110 to heat and keep the power battery warm.

[0049] When the vehicle is charged using the first external power source, the AC power from the first external power source is converted to DC power by the switching transistors M1-M6 of the three bridge arms of the PFC circuit 121. The power factor is improved by the PFC inductor L1, and after being filtered by the first capacitor C1, the DC power is converted into a voltage and current suitable for supplying power to the heater 110, so that the heater 110 generates heat, thereby heating and keeping the power battery warm.

[0050] According to one embodiment of the present invention, the on-board charger 120 is also used to charge the power battery based on electrical energy provided by a first external power source in a charging scenario.

[0051] In other words, when the vehicle uses a first external power source for charging, the electrical energy provided by the first external power source is converted into DC power by the on-board charger 120 and output to the power battery to charge the power battery. The following section combines... Figure 3The process of charging the power battery by the first external power source is explained.

[0052] Specifically, such as Figure 3 As shown, when the vehicle is charged using the first external power source, the AC power supplied by the first external power source is converted to DC power by the switching transistors M1-M6 of the three bridge arms of the PFC circuit 121. The power factor is improved by the PFC inductor L1, and after being filtered by the bus capacitor C1, the DC power is output to the DC-DC conversion circuit. The input and output currents are regulated by adjusting the switching frequency of the switching transistors M7-M10 of the primary-side switching circuit. The power is transferred to the secondary-side switching circuit through the first resonant inductor L2, the first resonant capacitor C2, the first transformer T1, the second resonant inductor L3, and the second resonant capacitor C3. The switching transistors M11-M14 of the secondary-side switching circuit are output rectifiers, which are rectified and then filtered by the fourth capacitor C4 to charge the power battery.

[0053] According to one embodiment of the present invention, such as Figure 4 As shown, a pre-charging circuit 130 is also provided between the on-board charger 120 and the power battery, which is used to pre-charge the power battery before charging it.

[0054] Specifically, the power battery may have a low voltage due to prolonged disuse or deep discharge. In this case, before charging the power battery, the pre-charging circuit 130 is activated first. The pre-charging circuit 130 pre-charges the battery with a low current, which is usually much lower than the maximum charging current of the power battery. Through pre-charging, a large current charging is avoided immediately when the power battery voltage is low, thus preventing a large surge current from being generated on the power battery or the on-board charger 120 at the start of charging and reducing damage to the power battery. The pre-charging circuit 130 can control the pre-charging time according to the state of the power battery and preset parameters. Once the power battery voltage reaches the preset threshold, the pre-charging circuit 130 will stop working.

[0055] In summary, the heat preservation circuit for the power battery in this embodiment of the invention can achieve the following beneficial effects:

[0056] (1) The heat preservation circuit of the present invention can reduce energy consumption in the heat preservation power supply of the plug gun. In related technologies, the heater is powered by two stages of PFC and DC-DC conversion by the on-board charger. The conversion efficiency of the common OBC (On-Board Charger) is 94%. However, the heat preservation circuit of the present invention reduces one stage of DC-DC conversion, with a common power supply efficiency of 98%, which can significantly reduce energy consumption.

[0057] (2) In non-AC charging or driving scenarios, the heater can be powered by a DC-DC converter circuit with regulated voltage, ensuring that the heating power does not decrease due to the drop in the power battery voltage due to the SOC (State of Charge). Furthermore, since the power supply voltage is adjustable and regulated, the high-voltage components of the heater are less likely to be damaged due to abnormal power supply voltage, greatly improving reliability.

[0058] (3) During the operation of the on-board charger, if the bus voltage of the on-board charger is abnormally high, the heater can be turned on to consume energy and protect the corresponding high-voltage devices on the bus, such as the bus capacitor and power switching tube.

[0059] (4) Furthermore, the on-board charger and heater can be integrated according to the new topology of this innovation to share some components and structural housing, which can reduce costs and reduce volume.

[0060] In summary, the power battery insulation circuit according to embodiments of the present invention supplies power to the heater based on the electrical energy of the power battery in non-charging scenarios, so that the heater can keep the power battery warm; in charging scenarios, it supplies power to the heater based on the electrical energy provided by a first external power source, so that the heater can keep the power battery warm. Therefore, this circuit, through innovative optimization of the vehicle's high-voltage architecture, eliminates the need for the heater to be directly connected in parallel with other high-voltage components for power, thereby reducing energy consumption and extending the service life of high-voltage components.

[0061] Corresponding to the above embodiments, the present invention also proposes a vehicle high-voltage circuit.

[0062] Figure 5 This is a block diagram of a vehicle high-voltage circuit according to an embodiment of the present invention.

[0063] like Figure 5 As shown, the vehicle high-voltage circuit 200 of this embodiment includes the above-mentioned heat preservation circuit 100.

[0064] According to the vehicle high-voltage circuit of the present invention, the above-mentioned heat preservation circuit can reduce energy consumption and extend the service life of high-voltage components.

[0065] Corresponding to the above embodiments, the present invention also proposes a vehicle.

[0066] like Figure 6 As shown, the vehicle 300 of this embodiment includes the above-described heat preservation circuit 100; or, as... Figure 7 As shown, another embodiment of the present invention, a vehicle 300, includes the vehicle high-voltage circuit 200 described above.

[0067] According to embodiments of the present invention, the vehicle's high-voltage circuit or insulation circuit described above can reduce energy consumption and extend the service life of high-voltage components.

[0068] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0069] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0070] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0071] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0072] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0073] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A heat preservation circuit for a power battery, characterized in that, include: A heater, wherein the heater is provided corresponding to the power battery; An on-board charger is connected to a first external power source, the power battery, and the heater. In a non-charging scenario, the charger supplies power to the heater based on the electrical energy from the power battery, enabling the heater to keep the power battery warm. In a charging scenario, the charger supplies power to the heater based on the electrical energy provided by the first external power source, enabling the heater to keep the power battery warm. The on-board charger includes a PFC circuit and a first DC-DC converter circuit. One end of the PFC circuit is connected to the first external power source, and the other end of the PFC circuit is connected to the heater and one end of the first DC-DC converter circuit via a first DC bus. The other end of the first DC-DC converter circuit is connected to the power battery via a second DC bus. In the non-charging scenario, the first DC-DC converter circuit supplies power to the heater based on the electrical energy of the power battery. In the charging scenario, the PFC circuit supplies power to the heater based on the electrical energy provided by the first external power source.

2. The heat preservation circuit according to claim 1, characterized in that, The heater includes a heating element and a heating switch, wherein the heating element and the heating switch are connected in series between the positive and negative terminals of the first DC bus.

3. The heat preservation circuit according to claim 2, characterized in that, The heating element is a PTC; and / or the heating switch is a power switching transistor; and / or the first external power supply is an AC power supply.

4. The heat preservation circuit according to claim 1, characterized in that, The PFC circuit is an interleaved PFC circuit.

5. The heat preservation circuit according to claim 1, characterized in that, The first DC-DC conversion circuit is an LLC resonant circuit or a CLLC resonant circuit.

6. The heat preservation circuit according to any one of claims 1-5, characterized in that, The on-board charger is also used to charge the power battery based on the electrical energy provided by the first external power source in the charging scenario.

7. The heat preservation circuit according to claim 6, characterized in that, A pre-charging circuit is also provided between the on-board charger and the power battery for pre-charging the power battery before charging it.

8. A high-voltage circuit for a vehicle, characterized in that, Includes the heat preservation circuit according to any one of claims 1-7.

9. A vehicle, characterized in that, This includes the thermal insulation circuit according to any one of claims 1-7, or the vehicle high-voltage circuit according to claim 8.

Images