Transmission line based short pulse generator with energy recovery

Abstract

A pulse generator (100) and a method for generating a pulse are provided. The pulse generator (100) includes: at least one first transmission line (110) having a first end and a second end; at least one second transmission line (120) having a first end and a second end; a voltage source (130); a switching unit (140); and a charging control device (135). The charging control device (135) is adapted to connect the output of the voltage source to the first end of the at least one first transmission line (120). A first switch S1 (150) in the switching unit (140) is adapted to connect or disconnect the second end of the at least one first transmission line (110) with the first end of the at least one second transmission line (120) within a predetermined time span. A second switch (S2) in the switching unit (140) is adapted to connect or disconnect the first end of the at least one second transmission line (120) with a fixed potential. The open state or the closed state of S1 (150) and S2 (160) in the switching unit (140) are mutually exclusive. The second end of at least one second transmission line (120) is adapted to be connected to a load (170). The switching unit (140) is further adapted to operate the first switch S1 (150) and the second switch S2 (160) in a predetermined sequence to change the pre-charge state of the first transmission line (110).

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the field of ballast water treatment. In particular, the present application relates to an apparatus and method for generating chemical reagents for treating ballast water. Background Art

[0002] Cruise ships, large tankers and bulk carriers use large amounts of ballast water to provide resistance against the lateral forces on the cruise ship, which are usually discharged in coastal waters of a region after the ship discharges waste water or unloads cargo and after unloading at the next port of call, takes on more cargo.

[0003] Ballast water discharges typically contain a variety of biological materials, including plants, animals, viruses, and other microorganisms. These materials often include non-native nuisance species that can cause widespread ecological and economic damage to aquatic ecosystems. Ballast water discharges are believed to be the leading source of invasive species in U.S. marine waters, thus posing a public health and environmental risk and causing significant economic losses to industries such as water and electric utilities, commercial and recreational fishing, agriculture, and tourism. Studies have shown that if nothing is done about ballast water management, invasive species can spread to any port in the world via a global shipping network that has an average of two intermediate stops.

[0004] Several methods for treating ballast water are known. For example, mechanical methods (e.g., filters). The disadvantage of filters is that the filter size for organisms is limited. It is possible that small organisms cannot be removed by the filter.

[0005] Physical or chemical methods are also known. For example, the physical method is to use ultraviolet radiation to irradiate organisms. Ultraviolet radiation is radiation with a very small wavelength, and the shorter the wavelength, the more harmful it is to organisms.

[0006] Chemical treatments, such as the addition of chlorine or ozone (O3) are also very effective for the medium to be treated, but chlorine in particular is highly toxic when inhaled and needs to be stored in special gas cylinders. Trained personnel are necessary to operate such systems.

[0007] A method for producing substances that can inactivate organisms in ballast water is to utilize a so-called dielectric barrier discharge (DBD) system.Dielectric barrier discharge has been applied as a source of reactive chemicals for treating ballast water.

[0008] The dielectric barrier discharge system generates plasma. The plasma is generated in a plasma reactor of the dielectric barrier discharge system. In particular, the plasma is generated in a gap between two electrodes. The gap may be partially filled with a dielectric. The dielectric may cover one or both of the electrodes. The electric pulse fed into the plasma reactor generates the plasma.

[0009] The plasma generates the substances necessary to inactivate or destroy organisms from the fluid (preferably gas) flowing in the gap during the discharge. For example, a plasma generator can generate ozone (O3) from oxygen (O2). For example, nitrogen oxides (NOX) can be generated from a mixture of O2 and nitrogen (N2). These substances are also called active substances.

[0010] For discharge barrier systems, a large surface in the reactor is usually required to discharge enough material. Therefore, the plasma reactor can be compared to a capacitor.

[0011] Since the surface can be very large, depending on the necessary amount of plasma or active species, the charging current for such a system is very high and results in a high capacitive load on the supporting voltage generator. In contrast, the discharge current for generating the plasma is small.

[0012] It turns out that pulses with high slew rates are advantageous when generating active species. For efficient chemical processes in the discharge, smaller rise times are preferred.

[0013] The generation of short voltage pulses with high power is generally not very efficient. In particular, when small rise times are applied, it is difficult to match the power supply to such a load. In case the load of such a circuit is not matched to the impedance of the cable, which is mainly the transmission line (e.g., which connects the power supply to the plasma reactor), or if the load is mainly capacitive, a large part of the transmitted power may be reflected back to the source. This energy is generally lost, making current solutions inefficient.

[0014] The present application seeks to provide a solution for improved pulse generation of plasma reactors and generally a method how the lost reflected energy can be recovered and at least partially reused. Summary of the invention

[0015] In order to solve the aforementioned problems and other potential problems, the embodiments of the present disclosure propose:

[0016] In a first aspect, a pulse generator is disclosed. The pulse generator includes at least one first transmission line having a first end and a second end. The pulse generator includes at least one second transmission line having a first end and a second end.

[0017] The pulse generator further comprises: a voltage source, a switching unit and a charge control device. The charge control device is adapted to connect the output of the voltage source to a first end of at least one first transmission line.

[0018] The switching unit comprises a first switch S1. The first switch S1 in the switching unit is adapted to connect or disconnect the second end of at least one first transmission line with the first end of at least one second transmission line within a predetermined time span.

[0019] The switching unit comprises a second switch S2. The second switch S2 is adapted to connect or disconnect the first end of the at least one second transmission line to a fixed potential. The open state and the closed state of S1 and S2 in the switching unit are mutually exclusive. The second end of the at least one second transmission line is adapted to be connected to a load.

[0020] The switching unit is adapted to operate the first switch and the second switch in a predetermined sequence to change a pre-charge state of the first transmission line.

[0021] In an embodiment, the switching unit is adapted to release an electric pulse which runs from the second end of the first transmission line through the second transmission line into the load; wherein at least a portion of the electric pulse is reflected toward the voltage source, wherein the switching unit is further adapted to pre-charge at least the first transmission line by operating the first switch S1 and / or the second switch S2 in a predetermined sequence so that at least a portion of the reflected portion of the electric pulse pre-charges at least the first transmission line.

[0022] A fixed potential may be understood as a potential associated with a voltage level. In particular, a "ground potential" may be considered a "fixed potential".

[0023] In a second aspect of the present application, a method for generating a pulse is disclosed. The method comprises: charging at least one first transmission line at a first end with an electric pulse; connecting the second end of at least one first transmission line to the first end of a second transmission line with a first switch S1 within a first predetermined time span; and simultaneously opening the second switch S2 to disconnect the first end of at least one second transmission line from a fixed potential; after a second predetermined time span, disconnecting the second end of at least one first transmission line from the first end of at least one second transmission line by opening the first switch S1 and connecting the first end of at least one second transmission line to the fixed potential by closing the second switch S2. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Embodiments of the present disclosure will be presented by way of example and their advantages will be explained in detail below with reference to the accompanying drawings, in which:

[0025] Figure 1 shows a circuit diagram according to an embodiment of the present application;

[0026] Figure 2 A schematic circuit diagram of an embodiment of the present application is shown;

[0027] Figure 3 A measurement diagram is shown. DETAILED DESCRIPTION

[0028] Hereinafter, the principles and spirit of the present disclosure will be described with reference to illustrative embodiments. It should be understood that all these embodiments are given only to allow those skilled in the art to better understand and further practice the present disclosure, but are not used to limit the scope of the present disclosure. For example, the features shown or described as part of one embodiment can be used together with another embodiment to produce a further embodiment. For the sake of clarity, all features of the actual implementation are not described in this specification. It is certainly appreciated that in developing any such actual embodiment, many implementation-specific decisions should be made to achieve the specific goals of the developer, such as complying with system-related and business-related constraints, which will change from one implementation to another. In addition, it will be appreciated that such development work may be complex and time-consuming, but it will be routine work for those of ordinary skill in the art who benefit from the present disclosure.

[0029] The disclosed subject matter will now be described with reference to the accompanying drawings. Various structures, systems and devices are schematically depicted in the accompanying drawings for illustrative purposes only, and the description is not obfuscated with details known to those skilled in the art. However, the drawings are included to describe and explain illustrative examples of the disclosed subject matter. The words and phrases used herein should be understood and interpreted as having meanings consistent with the understanding of these words and phrases by those skilled in the relevant art. Special definitions of terms or phrases, i.e., definitions that are different from the ordinary and customary meanings understood by those skilled in the art, are not intended to be implied by the consistent use of the terms or phrases herein. To the extent that terms and phrases may be intended to have special meanings, i.e., meanings that are different from those understood by the technicians, such special definitions will be clearly stated in the specification in a direct and clearly provided definition manner to specifically set forth the special definitions used for the terms or phrases.

[0030] The capacitive loading of current DBD reactors can result in high currents; furthermore, if the load does not match the impedance of the transmission line, much of the transmitted power is reflected back to the source. The current solution is to try to match the load and source as well as possible; the losses caused by the mismatch are acceptable.

[0031] The arrangement of a pulse generator for a component test unit is, for example, as follows: the pulse generator uses a transmission line charged by a MARX generator as an energy storage device for subsequently deployed pulses from a second transmission line. With these pulses, the ESD behavior of, for example, an integrated circuit (IC) is tested. The load (e.g., an IC on a test board) is usually not very well matched to the transmission line. Depending on the matching, the ESD test pulse is partially reflected. However, this reflected pulse will interfere with the transmitted pulse and hinder the measurement at the CUT. Therefore, matching impedances must be used to avoid reflections. The reflected pulse energy is lost.

[0032] According to the present disclosure, a different concept is provided that allows to recapture at least a portion of the reflected energy pulse by clever use of semiconductor switches and by storing this energy in the transmission line. For the next switching cycle, the transmission line is already pre-charged and less energy is required for charging.

[0033] As used herein, pre-charging or being pre-charged is generally understood as a process or state in which the electrical energy level in the corresponding part is increased compared to the initial state. For example, when the first transmission line is pre-charged, it includes an initial energy level that is higher than the state in which the pulse generator is not working. The energy level can be represented by a peak voltage within the first transmission line. As an example and not a limitation, it is assumed that the initial energy level exists when the pulse generator has not been operated for at least one hour. In this exemplary illustration, the pre-charge state of the first transmission line is, for example, more than 500V, more than 1kV, or more than 2kV higher than the initial energy level.

[0034] The transmission line 110 for storing energy is charged by using a power source 130, preferably a DC power source.

[0035] A switch S1 150 connecting the first transmission line to the second transmission line may be switched from an open state to a closed state, and a substantially rectangular pulse (having a pulse length defined by the length of the first transmission line 110) propagates from the first transmission line 110 to the second transmission line 120. The first transmission line is discharged.

[0036] The end of the second transmission line 120 may be connected to a load that may not perfectly match the impedance of the transmission line. The pulse reaches the load and its voltage acts on the load; depending on the mismatch between the load and the second transmission line 120, a significant portion of the pulse may be reflected back to the second transmission line and run back toward the first transmission line 110.

[0037] When the switch S1 is still kept closed and when the impedances of the transmission lines 110 , 120 are matched, the reflected pulse enters the first transmission line without substantial reflection.

[0038] Now, preferably, just when a pulse with the same length as the first transmission line 110 (due to its length being changed by the reflection) fills up the line, the switch S1 is opened again. The pulse is then "trapped" and the line is precharged with a voltage given by the average voltage of the reflected pulse. (Pulse trap)

[0039] This means that for the following pulse, the DC source must provide less energy than for a non-precharged transmission line, and the reflected energy from the load is reused - it does not increase the losses in the system. As will be described in detail in the specification, if a diode is used to recapture the pulse, it is not necessary to time the closure of the switch precisely; for a typical MOSFET switch, such a diode is already in place.

[0040] In a first embodiment of the present application, a pulse generator may be disclosed. The pulse generator may include at least one first transmission line 110 having a first end and a second end. In addition, the pulse generator may also include at least one second transmission line 120 having a first end and a second end.

[0041] The pulse generator may further comprise a voltage source or voltage supply 130, a switching unit 140 and a charge control device 135. The charge control device 135 may further be adapted to connect the output of the voltage source 130 to the first end of the at least one first transmission line 110.

[0042] The switching unit 140 may include a first switch S1. The first switch S1 in the switching unit may be adapted to connect or disconnect the second end of the at least one first transmission line with the first end of the at least one second transmission line within a predetermined time span. The predetermined time span depends, for example, on the transmission line length and the propagation time of the pulse on the transmission line. Preferably, the length of the transmission lines 110, 120 is such that the pulse can completely "fit" into the transmission line.

[0043] The second switch S2 in the switching unit 140 may be adapted to connect or disconnect the first end of the at least one second transmission line 120 to or from a fixed potential. For example, the fixed potential may be a "ground potential". The open state and the closed state of S1 and S2 in the switching unit 140 are preferably mutually exclusive. The second end of the at least one second transmission line is adapted to be connected to a load 170.

[0044] The switching unit 140 may be adapted to release an electric pulse from the second end of the first transmission line 110 through the second transmission line 120 into the load 170A. A portion of the electric pulse may be reflected toward the voltage source 130.

[0045] The switching unit 140 may also be adapted to precharge at least the first transmission line 110 by operating the switches S1 and / or S2 in a predetermined sequence such that at least a portion of the reflected portion of the electrical pulse precharges at least the first transmission line 110. In other words, the energy contained in the reflected pulse, which is a small portion of the initial pulse from the source 130, is now contained in at least the first transmission line 110. The level of reflection of the reflected pulse generally depends on the degree of matching of the load 170 with the second end of the at least one second transmission line 120. In other words, due to the mismatch between the second end of at least the second transmission line 120 and the load 170, a portion of the pulse running into the load may be reflected.

[0046] This may increase the voltage level in the at least one first transmission line 110. Less charging from the voltage source 130 may be required. Before pre-charging, the previous voltage level in the at least one first transmission line 110 may have been about zero volts. Thus, the voltage source 130 only needs to deliver a reduced amount of energy to fully charge at least the first transmission line 110. The pulse (energy of the pulse) reflected at the load (a portion of the initial pulse) is reused and the efficiency of the pulse generator is improved in an advantageous manner, thereby increasing the generation of active substances in the DBD reactor.

[0047] Figure 2 A schematic diagram of the arrangement of the present application is shown. 130 is a DC voltage generator capable of outputting a DC voltage. The DC voltage generator has an output at which a DC voltage is available.

[0048] Switch 135 (S0) connects the output of the DC generator to the input (first end) of the transmission line 110. Similar to a capacitor, when switch S0 is closed, the first transmission line is charged. The transmission line is preferably a coaxial cable, which can be considered as a cylindrical capacitor.

[0049] The transmission line 110 is charged by a DC generator and stores a certain amount of energy. This amount depends on the geometrical properties of the transmission line. Some properties are length, diameter, dielectric.

[0050] If the voltage at the transmission line 110 reaches a certain level, S0 can be opened. Energy from the power supply is stored in the transmission line 110 (T1). A pulse is started by opening S2 and closing S1. Switches S1 / S2 are preferably opened and closed simultaneously.

[0051] The pulse begins to propagate from the first transmission line 110 (T1) to the second transmission line 120 (T2). The transmission line 120 may have at least the same length as the transmission line 110. The impedances of the first transmission line 110 and the second transmission line 120 may be matched so that there are no reflections at their connection points.

[0052] After a while, the leading edge of the pulse reaches the reactor. At this point, the end of the pulse is contained in the second transmission line 120. T1 is completely discharged at a voltage level of substantially 0 volts. On the reactor side, which is mainly a capacitive load, a portion of the pulse is reflected and returns toward the first transmission line 110 due to a.

[0053] When the end of the reflected pulse leaves the second transmission line 120 and enters the first transmission line 110 again (the head of the pulse then arrives just at the left end / first end of T1), S1 opens to capture the pulse and S2 closes to "ground" the second transmission line 120 or connect it to a fixed potential: the pulse is now captured inside T1, which is now in a "pre-charge" state, where the "pre-charge" is the captured reflected pulse.

[0054] The charging voltage is generally less than the voltage generated from the initial pulse - some energy has been used in the reactor. However, the energy stored in T1 reduces the energy required to fully charge the transmission line 110 (T1) to the initial voltage provided when S0 is closed again.

[0055] In other words, the application can ensure that in the pulse generator, the switching unit 140 is suitable for operating the switches S1 and / or S2 in a predetermined sequence so that the energy included in the electrical pulse is captured in at least the first transmission line 110, and the electrical pulse is reflected back to at least the first transmission line 110 from the second end of at least one second transmission line 120.

[0056] Figure 1 An implementation of such a system is shown, also including some variations. A large resistor has been used instead of switch S0. The resistor has a high resistance and can therefore act as an open switch during the pulse, but allows the voltage generator 130 (FUG) to charge slowly. In a non-limiting example, the length of the second transmission line 120 has been chosen to be twice the length of the first transmission line 110.

[0057] S1 and S2 are implemented by commercially available MosFet switches. These MosFet switches may already contain a freewheeling diode arranged in parallel with each switch S1, S2.

[0058] The diode can be used to capture the back-reflected pulse without synchronization: switch S1 is closed during the propagation of the pulse in the transmission line 120. The reflected pulse can be directed back to the transmission line 110 via the upper diode arranged electrically in parallel with S1.

[0059] In a non-limiting example, the on-time of the MOSFET switch is set to t=274 ns and the cable is charged to a voltage U=4.5 kV.

[0060] Figure 3The charging voltage and pulse voltage are shown. The pulse width is about 100ns and the voltage rise time (0V to U max ) is t=30ns. The voltage of the charging cable (first transmission line 110) drops from 4573V to 2090V, and about 21% of the energy is recovered.

[0061] The types of switches described are exemplary only. Other switching devices may also be used. Figure 1 The circuit may further comprise a control module (not shown here). The control module may be configured to coordinate the switching process. The control module may be configured to determine the voltage at the first transmission line and be connected to the switches S1, S2.

[0062] The control module may also determine the pulse characteristics (rise time, length) and control the switches in the switching unit 140 accordingly. The control module is configured to determine if the end of the reflected pulse has entered the first transmission line 110 and may operate the switches S1 / S2.

[0063] Another embodiment according to other aspects discloses a pulse generator, wherein the characteristic impedance of at least one first transmission line 110 corresponds to the characteristic impedance of at least one second transmission line 120. Preferably, the two transmission lines have corresponding characteristic impedances to avoid reflections of pulses at the connection point, in particular at the connection point where the end of the first transmission line 110 is connected to the input of the second transmission line 120, to avoid reflections of the pulses at this point.

[0064] Another embodiment discloses a pulse generator according to one or more aspects of the present application, wherein at least one second transmission line 120 is longer than at least one first transmission line 110. The longer second transmission line ensures that the pulse length containing the energy of the first transmission line fits completely into the second transmission line.

[0065] Another embodiment discloses a pulse generator according to one or more aspects of the present application, wherein the charge control device 135 can be from the group consisting of: a resistor, a semiconductor, and a mechanical switch.

[0066] The actual charging of the first transmission line 110 is a substantially continuous and relatively slow process. The duty cycle of the reactor may be between 1% and 10%. This means that the voltage supply may be relatively cheap, as it is more important to support sufficient voltage rather than to carry high current.

[0067] Figure 1 The voltage supply is shown connected to the first transmission line via a charge control device 135 in the form of a 10Mohm resistor. This may result in a low charging current. When the pulse is triggered, the resistor can be enabled and the voltage supply does not have to be removed.

[0068] If resistor 135 is to be replaced by a switch as a charge control device, and the voltage supply is to support high charging currents, the switch must be opened ( Figure 2 S0 in the circuit to ensure that pulse generation is not affected by the charging current.

[0069] Another embodiment discloses a pulse generator according to one or more aspects of the present application, wherein the first switch 150 and the second switch 160 in the switching unit 140 include semiconductors and wherein the switching unit 140 is configured so that switching times for the first switch and the second switch can be predetermined.

[0070] In particular, the switching unit may be controlled by a control unit. The control unit may be configured to adjust the switching time of the switch S1 / S2 .

[0071] The switching device itself may include a control unit, which may be configured to determine the charging state of the first transmission line and coordinate the switching state and switching time of S1 / S2 .

[0072] Another embodiment discloses a pulse generator according to one or more aspects of the present application, wherein the transmission line includes a coaxial cable.

[0073] Preferably, the transmission line can be realized by a coaxial cable. The advantage of coaxial cables as transmission lines is that they have a defined characteristic impedance. In a specific frequency band, the resistance remains essentially resistive. The rise time of the voltage pulse is such that the frequencies contained in the pulse are within the frequency band. The characteristic impedance of commercially available transmission lines (coaxial cables) is 50 ohm or 75 ohm. These two values ​​are only exemplary, because other values ​​of the characteristic impedance are possible depending on the geometrical properties of the cable.

[0074] The property that is relevant to impedance is the diameter or thickness of the center conductor (if it is a coaxial cable).

[0075] In another embodiment of the present application, the shielding of the transmission lines 110, 120 may be connected to ground or a fixed potential at more than one point of the shielding. This may serve as an improved potential equalization.

[0076] Another embodiment discloses a pulse generator according to one or more aspects of the present application, further comprising a network interface for connecting the pulse generator to a data network, wherein the pulse generator is operably connected to the network interface for at least one of the following: executing a command received from the data network, and sending a device state to at least one task in the data network. Another embodiment may disclose a pulse generator according to one or more aspects of the present application, wherein the network interface is configured to transmit and receive digital signals / data between the pulse generator and the data network, wherein the digital signals / data include operating commands and / or information about the pulse generator or the network, and further comprising a processing unit for converting the signal into a digital signal or processing the signal.

[0077] The latter embodiment may enable the DBD system to be controlled externally. This may be necessary, for example, if the dielectric barrier discharge system is on board a ship and has to be maintained.

[0078] Another embodiment discloses a method for generating a pulse. The method includes: charging at least one first transmission line with an electrical pulse at a first end; connecting the second end of at least one first transmission line 110 with the first end of at least one second transmission line 120 using a switch S1 150 in a switching unit 140 within a first predetermined time span, and; substantially simultaneously opening a switch S2 160 in the switching unit 140 to disconnect the first end of at least one second transmission line from a ground potential; after a second predetermined time span, disconnecting the second end of at least one first transmission line 110 from the first end of at least one second transmission line 120 by opening the switch S1 150, and connecting the first end of at least one second transmission line 120 to the ground potential by closing the switch S2 in the switching unit 140.

[0079] The advantage of this method is that the voltage source does not need to deliver high currents. This is because the voltage source must first charge the energy storage device provided in the form of the first transmission line. Considering that the plasma is generated only about 1% to 10% of the time, the DC voltage generator has enough time to reload the energy storage device.

[0080] This means that there is no need to use a high voltage source, which can also provide high currents, but a less powerful but cheaper energy source will suffice.

[0081] Another advantage is that this method saves energy. In conventional DBD systems, the energy reflected at the connection point of the cable and the reactor is lost. Therefore, the efficiency of conventional systems is very low because these reactors have a mismatch between the cable and the reactor input. Inevitably, reflection of the voltage pulse occurs and the energy of the reflected pulse is lost.

[0082] By appropriate operation of the switch, the reflected energy is at least partially stored back in the first transmission line. This means that the energy storage device will be pre-charged with the energy of the reflected pulse. Next, activating the plasma reactor with a voltage pulse, the energy storage device pre-charged with the energy reflected from the most recent pulse must be charged with an amount of energy that is less than necessary, as if the energy storage device would be empty at the beginning of charging.

[0083] Figure 1 An exemplary embodiment of a circuit that can perform this method is shown. A voltage generator 130 (FUG) charges the transmission line 110 with a specific charge. The charge is determined by the specifications of the transmission line itself.

[0084] The charge depends on the breakdown voltage, which is the maximum voltage before discharge occurs between conductors in a transmission line (preferably a coaxial cable). Additionally, the charge depends on the length of the transmission line. The longer the transmission line 110, the higher the level of charge.

[0085] If the transmission line 110 is fully charged, which can be determined by its voltage, the switch S1 is closed and S2 is opened. The complete charge moves into the second transmission line 120. This does not happen instantaneously like a normal capacitor. The charge forms a pulse with a pulse length, which propagates on the second transmission line 120 towards the input of the inductor 170 at a certain speed. The propagation speed on the transmission line is also a characteristic of the transmission line.

[0086] The voltage pulse has a front end and an end. The voltage pulse is completely contained in the second transmission line. The first transmission line is not charged. The voltage pulse also propagates on the second transmission line 120 and enters the inductor 170.

[0087] Now assume that the second transmission line 120 and the reactor 170 are not matched. This means that the characteristic impedance of the second transmission line 120 is different from or similar to the impedance of the reactor 170. A portion of the voltage pulse propagates into the reactor 170 and a second portion of the pulse is reflected back to the voltage generator 130.

[0088] It is assumed that the propagation speed of the transmission lines 110, 120 and the pulse length are known. From these values, it can be determined when the end of the reflected pulse leaves the first end of the second transmission line 120. The pulse and its energy are now contained in the first transmission line 110 and raise the voltage level in the first transmission line 110 to a certain level corresponding to the energy of the reflected pulse.

[0089] The transmission line 110 now has a “starting” voltage level and the voltage source only needs to charge the transmission line 110 with this difference.

[0090] according to Figure 1, when the reflected pulse propagates back to the first transmission line, it may not be necessary to close S1. Even if S1 is open, the reflected pulse can propagate to the transmission line 110 through the freewheeling diode switched in parallel with S1.

[0091] In addition, features illustrated or described as part of one embodiment may be used on or in conjunction with other embodiments to yield yet further embodiments, and the description is intended to include such modifications and variations.

[0092] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

1. A pulse generator, comprising: at least one first transmission line having a first end and a second end; at least one second transmission line having a first end and a second end; Voltage source; Switching unit; Charging control equipment; wherein The charging control device is further adapted to connect the output of the voltage source to the first end of the at least one first transmission line; The first switch S1 in the switching unit is adapted to connect or disconnect the second end of the at least one first transmission line with the first end of the at least one second transmission line within a predetermined time span, and The second switch S2 in the switching unit is adapted to connect or disconnect the first end of the at least one second transmission line to a fixed potential, wherein the open state or the closed state of S1 and S2 in the switching unit are mutually exclusive; The second end of the at least one second transmission line is adapted to be connected to a load; wherein The switching unit is further adapted to operate the first switch S1 and the second switch S2 in a predetermined sequence to change a pre-charge state of the first transmission line; wherein the switching unit is adapted to release an electrical pulse, the electrical pulse running from the second end of the first transmission line through the second transmission line into the load; wherein at least a portion of the electrical pulse is reflected towards the voltage source, The switching unit is further adapted to operate the first switch S1 and / or the second switch S2 in the predetermined sequence so that at least a part of the reflected portion of the electrical pulse pre-charges the at least first transmission line.

2. The pulse generator according to claim 1, wherein The switching unit is adapted to capture in the at least first transmission line at least a non-negligible portion of the energy comprised in the electrical pulse reflected back from the at least one second transmission line to the at least first transmission line by operating the switches S1 and / or S2 in a predetermined sequence. 3 . The pulse generator according to claim 1 , wherein the switching unit is adapted to operate the first switch S1 and the second switch S2 so that each of them is in an ON state for a predetermined period of time. 4 . The pulse generator of claim 1 , wherein a characteristic impedance of the at least one first transmission line corresponds to a characteristic impedance of the at least one second transmission line.

5. The pulse generator of claim 1, wherein the at least one second transmission line is longer than the at least one first transmission line.

6. The pulse generator of claim 1, wherein the charge control device can be from the group consisting of: a resistor, a semiconductor, a mechanical switch. 7 . The pulse generator of claim 1 , wherein the first switch and the second switch in the switching unit comprise semiconductors, and wherein the switching unit is configured such that switching times for the first switch and the second switch can be predetermined.

8. The pulse generator of claim 1, wherein the voltage source has a characteristic impedance having a value less than three times the impedance of the at least one first transmission line.

9. The pulse generator of claim 1, wherein the transmission line comprises a coaxial cable.

10. The pulse generator of claim 1, wherein a shield of the transmission line is connected to ground potential.

11. The pulse generator according to claim 1 further includes a network interface for connecting the pulse generator to a data network, wherein the pulse generator is operably connected to the network interface for at least one of the following: executing commands received from the data network and sending device status information to the data network.

12. The pulse generator of claim 11, wherein the network interface is configured to transmit and receive digital signals / data between the pulse generator and the data network, wherein The digital signal / data includes commands and / or information regarding the operation of the pulse generator or the network, and also includes a processing unit for converting the signal into a digital signal or processing the signal.

13. The pulse generator according to any one of claims 1-12, wherein the load is a capacitive load.

14. A method for generating a pulse, comprising: charging at least one first transmission line at a first end with an electrical pulse; connecting the second end of the at least one first transmission line to the first end of the at least one second transmission line using a first switch S1 within a first predetermined time span; Simultaneously opening the second switch S2 to disconnect the first end of the at least one second transmission line from the fixed potential; after a second predetermined time span, disconnecting the second end of the at least one first transmission line from the first end of the at least one second transmission line by opening the first switch S1, and connecting the first end of the at least one second transmission line to a ground potential by closing the second switch S2; The switching unit is adapted to release an electrical pulse, which runs from the second end of the first transmission line through the second transmission line into a load; wherein at least a portion of the electrical pulse is reflected towards a voltage source, The switching unit is further adapted to operate the first switch S1 and / or the second switch S2 in a predetermined sequence so that at least a part of the reflected portion of the electrical pulse pre-charges the at least first transmission line.

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