A control circuit for generating a primary alternating current (AC) voltage signal provided to a dielectric barrier discharge (DBD) disk of a three-dimensional printer includes a switching regulator receiving a direct current (DC) voltage signal. The switching regulator modulates the DC voltage signal based on a variable duty cycle to create a modulated DC signal. The control circuit also includes a modulation circuit in electrical communication with the switching regulator. The modulation circuit introduces a frequency component to the modulated DC signal, where the primary AC voltage signal includes a variable duty cycle and a set frequency, and the frequency component introduced into the modulated DC signal is representative of the set frequency of the primary AC voltage.

Some embodiments are directed to a generator and separator assembly for generating ions via atmospheric pressure, low temperature plasma and separating the generated ions. The generator and separator assembly include a plasma generator for generating the generating atmospheric pressure, low temperature plasma that is configured to eject positively and negatively ions. A separator is disposed to receive the positively and negatively ions ejected from the plasma generator, and includes a first separator electrode; a second separator electrode spaced from the first separator electrode; and a separator power supply that supplies electric power in the form of at least one of different voltages and different polarities to the first and second electrodes ranging from 0 kV and 10 kV, such that the received positively charged ions are redirected in one direction and the received negatively charged ions are redirected to another direction different from the one direction.

A method of operating a piezoelectric plasma generator including applying an input signal to a piezoelectric transformer of the piezoelectric plasma generator. An absolute value of a peak amplitude of the input signal is periodically reduced and increased to a level smaller and larger than an ignition voltage of the plasma generator, such that plasma generation periodically collapses.

Energy is generated from pulsed electric power sources applied to a gas medium that includes hydrogen. A sealed reactor chamber contains hydrogen. A plasma power supply, such as a DC, AC, or RF power supply, generates a plasma inside the chamber. The pulse energy generator systems use pulsed electric power for the conversion of molecular hydrogen into atomic hydrogen. An inner surface of the reactor chamber is coated with a catalyst to facilitate the reformation of molecular hydrogen from atomic hydrogen under conditions that release excess energy. The catalyst may include tungsten, nickel, titanium, platinum, palladium, and mixtures thereof. A plasma pulse controller connected to the plasma power supply turns the power supply on and off to generate plasma pulses inside the reactor chamber. A pulse time duration may range from 1 nanosecond to 1 millisecond and a dead time between pulses may range from 20 milliseconds to 0.3 seconds.

Systems, devices, and methods generating a plasma flow are disclosed. A method may include applying energy that alternates between being at a base level for a first duration and at a pulse level for a second duration according to a controlled pattern, generating a plasma flow having a directional axis, and discharging the plasma flow alternating between a base configuration and a pulse configuration according to the controlled pattern. The plasma flow in the base configuration may have (1) a first temperature at the outlet and (2) a first flow front that advances along the directional axis. The plasma flow in the pulse configuration may have (1) a second temperature at the outlet that is greater than the first temperature and (2) a second flow front that advances along the directional axis at a speed greater than the first flow front.

A system for plasma ignition and maintenance of an atmospheric pressure plasma. The system has a variable frequency alternating current (AC) power source, a transformer, a cable connected to a secondary winding of the transformer, a programmed microprocessor for control of power to the atmospheric pressure plasma. The microprocessor is configured to a) at pre-ignition, power the AC power source at an operational frequency f.sub.op higher than the resonant frequency f.sub.r, b) decrease the operational frequency f.sub.op of the AC power source until there is plasma ignition, and c) after the plasma ignition, further decrease the operational frequency f.sub.op of the AC power source to a frequency lower than the resonant frequency f.sub.r.

A secondary bobbin of a high-voltage transformer and a portable plasma device including the same are provided to regulate discharge voltage. The secondary bobbin of the high-voltage transformer includes: a main body; barrier portions dividing the main body into a predetermined number of multiple segments along the length of the main body; winding portions where a coil is wound on the multiple segments into which the main body is divided; and switch circuit portions connecting neighboring barrier portions by a switch, wherein the switch circuit portions electrically connect or disconnect the winding portions to adjust the number of turns depending on whether the switch circuit portions are on or off.

A system for generation of radicals in a liquid (e.g., OH and derivatively H.sub.2O.sub.2 in water) by a plasma reactor, including a first electrode having a rod shape or a tubular shape; a dielectric tubular housing coaxial with the first electrode and enclosing the first electrode, and having a gap to the first electrode of 0.3-30 mm; a second electrode on an outside of the dielectric tubular housing and coaxial with first electrode with a gap 0.3-30 mm; a high voltage power supply providing voltage oscillations or pulses of 0.5-30 kV and a frequency 1-50 kHz between the first and second electrodes; and a pump or a Venturi injector on an output of the plasma reactor and a chock valve on an input of reactor for generating a low water pressure in the gap between first and second electrodes so as to generate boiling in the gap.

The present disclosure relates to a portable plasma device which is convenient to carry and has excellent performance and is capable of simply, uniformly, and locally treating an inner surface of a microstructure such as a microwell plate by easily adjusting a plasma flame.

A plasma assisted spark ignition system includes an ignitor and a power supply. The first ignitor includes: a casing having a first end, a second end that forms a first electrode, and a longitudinally extending passage, a second electrode which protrudes longitudinally outward from an opening at the second end of the casing and laterally spaced inwardly to form a spark gap, and an electrical insulator (dielectric) surrounding a portion of the second electrode, and which has a terminus that is at least closely spaced to an interior surface of the end of the casing. The power supply supplies a plurality of voltage pulses to the ignitor per ignition event to generate a flash over on the dielectric. Subsequent pulses in an ignition event may be at lower amplitude than an initial pulse in the ignition event. Pulses may, for example, have a duration on the order of a nanosecond.