In accordance with the present disclosure, exposure of a sample to one or more electric pulses via capacitive coupling is described. In certain embodiments, the sample may be a biological sample to be treated or modified using the pulsed electric fields. In certain embodiments, the electric pulses may be delivered to a load using capacitive coupling. In other embodiments, the electric pulses may be bipolar pulses.

A joining device includes: a first circuit in which a primary-side winding of a first transformer and a first capacitor are connected; a second circuit in which a primary-side winding of a second transformer and a second capacitor are connected; an electrode connected to secondary-side winding of the first transformer and secondary-side winding of the second transformer; and a charge switch configured to switch between energization/de-energization of the first and second capacitors from a power supply without the transformers being interposed. The first circuit has a first discharge switch and the second circuit has a second discharge switch. A method for manufacturing a joined object includes, by using the joining device, supplying an object to be joined to be sandwiched by the electrode; causing a current to flow through the electrode that sandwiches the object to be joined to join the object to be joined.

Some embodiments include a thermal management system for a nanosecond pulser. In some embodiments, the thermal management system may include a switch cold plates coupled with switches, a core cold plate coupled with one or more transformers, resistor cold plates coupled with resistors, or tubing coupled with the switch cold plates, the core cold plates, and the resistor cold plates. The thermal management system may include a heat exchanger coupled with the resistor cold plates, the core cold plate, the switch cold plate, and the tubing. The heat exchanger may also be coupled with a facility fluid supply.

Some embodiments may include a nanosecond pulser comprising a plurality of solid state switches; a transformer having a stray inductance, L.sub.s, a stray capacitance, C.sub.s, and a turn ratio n; and a resistor with a resistance, R, in series between the transformer and the switches. In some embodiments, the resonant circuit produces a Q factor according to

[00001]$Q=\frac{1}{R}\sqrt{\frac{L_s}{C_s}},$

and the nanosecond pulser produces an output voltage V.sub.out from an input voltage V.sub.in, according to V.sub.out=QnV.sub.in.

A light emitting device includes a wiring board having a first wiring layer and a second wiring layer adjacent to the first wiring layer via an insulating layer, and a laser having a cathode electrode and an anode electrode, mounted on the wiring board, and driven through low-side driving. The first wiring layer includes a cathode wire connected to the cathode electrode, an anode wire connected to the anode electrode, and a first reference potential wire connected to a reference potential. The second wiring layer includes a second reference potential wire connected to the reference potential. An area of an overlap between the second reference potential wire and the anode wire is larger than an area of an overlap between the second reference potential wire and the first reference potential wire.

It would be advantageous to reduce weight and size of high voltage power supplies, to increase frequency of pulses of high voltage, and to improve control of magnitude of high voltage. The embodiments of high voltage power supplies described herein can solve these problems. The high voltage power supply can be used with an x-ray tube. The high voltage power supply can comprise an array of planar transformers each defining a stage with an AC input and a DC output. Each stage can comprise a pair of flat, coil windings adjacent one another and including a primary winding electrically-coupled to the AC input and configured to induce a current in a secondary winding. At least two stages can be electrically-coupled together in series with the DC output of one stage electrically-coupled to an input of the other stage such that a voltage is amplified across the stages.

Some embodiments include a high voltage pulsing power supply. A high voltage pulsing power supply may include: a high voltage pulser having an output that provides pulses with an amplitude greater than about 1 kV, a pulse width greater than about 1 μs, and a pulse repetition frequency greater than about 20 kHz; a plasma chamber; and an electrode disposed within the plasma chamber that is electrically coupled with the output of the high voltage pulser to produce a pulsing an electric field within the chamber.

Some embodiments include a high voltage, high frequency switching circuit. The switching circuit may include a high voltage switching power supply that produces pulses having a voltage greater than 1 kV and with frequencies greater than 10 kHz and an output. The switching circuit may also include a resistive output stage electrically coupled in parallel with the output and between the output stage and the high voltage switching power supply, the resistive output stage comprising at least one resistor that discharges a load coupled with the output. In some embodiments, the resistive output stage may be configured to discharge over about 1 kilowatt of average power during each pulse cycle. In some embodiments, the output can produce a high voltage pulse having a voltage greater than 1 kV and with frequencies greater than 10 kHz with a pulse fall time less than about 400 ns.

Some embodiments include a high voltage, high frequency switching circuit. The switching circuit may include a high voltage switching power supply that produces pulses having a voltage greater than 1 kV and with frequencies greater than 10 kHz and an output. The switching circuit may also include a resistive output stage electrically coupled in parallel with the output and between the output stage and the high voltage switching power supply, the resistive output stage comprising at least one resistor that discharges a load coupled with the output. In some embodiments, the resistive output stage may be configured to discharge over about 1 kilowatt of average power during each pulse cycle. In some embodiments, the output can produce a high voltage pulse having a voltage greater than 1 kV and with frequencies greater than 10 kHz with a pulse fall time less than about 400 ns.

A generator includes a series-connected inductive energy store and a superfast drift step recovery diode, as well as a load connected in parallel to the drift step recovery diode and switches. The switches are arranged in series, and the inductive energy storage device is connected to the point of connection of the switches therebetween and adjusting the amplitude of the pulses on the load by changing the closing and opening times of the switches. The moment of closing of the second switch is in the time interval between the opening of the first switch and changing of the polarity of the current through the inductive storage, wherein the time of its opening is in the interval of time from the beginning of the pulse formation on the load until the next closure of the first switch.