A piezoelectric actuator control device comprising a first voltage converter supplying a DC voltage on a DC power supply bus to which is connected a second voltage converter capable of generating a variable excitation voltage under the control of a control computer, the second voltage converter comprising two switch half-bridges mounted in parallel with the terminals of a bus capacitor, the control computer being suitable for controlling the two switch half-bridges according to a first control configuration, in which they are controlled independently in order to each supply a voltage in a range between zero and a maximum positive value and according to a second control configuration, in which they are jointly controlled as a full-bridge for supplying a voltage between a minimum negative value and said maximum positive value.

A system is disclosed for restoring a surface field potential of an electret material. An oscillator generates an oscillating output, and a power amplifier amplifies the oscillating output. A step-up transformer generates a high voltage alternating current output from the amplified oscillating output, and a polarity controller generates one of a positive pulsating output and a negative pulsating output from the high voltage alternating current output.

A system is disclosed for restoring a surface field potential of an electret material. An oscillator generates an oscillating output, and a power amplifier amplifies the oscillating output. A step-up transformer generates a high voltage alternating current output from the amplified oscillating output, and a polarity controller generates one of a positive pulsating output and a negative pulsating output from the high voltage alternating current output.

A high voltage power system is disclosed. In some embodiments, the high voltage power system includes a high voltage pulsing power supply; a transformer electrically coupled with the high voltage pulsing power supply; an output electrically coupled with the transformer and configured to output high voltage pulses with an amplitude greater than 1 kV and a frequency greater than 1 kHz; and a bias compensation circuit arranged in parallel with the output. In some embodiments, the bias compensation circuit can include a blocking diode; and a DC power supply arranged in series with the blocking diode.

Electrical apparatus to kill a plant or at least attenuate plant growth, the apparatus comprising: an electrical energy supply unit; a applicator unit comprising an applicator electrode; a return unit comprising a return electrode; the electrical energy supply unit arranged to apply electrical energy through a transmission circuit comprising the applicator electrode, and the return electrode, the electrical energy supply unit including a plurality of transformers, each transformer having a low voltage side and a high voltage side, wherein the high voltage sides of the transformers are electrically connected to implement transmission circuit, and/or the low voltage sides of the transformers are electrically connected.

Electrical apparatus to kill a plant or at least attenuate plant growth, the apparatus comprising: an electrical energy supply unit; a applicator unit comprising an applicator electrode; a return unit comprising a return electrode; the electrical energy supply unit arranged to apply electrical energy through a transmission circuit comprising the applicator electrode, and the return electrode, the electrical energy supply unit including a plurality of transformers, each transformer having a low voltage side and a high voltage side, wherein the high voltage sides of the transformers are electrically connected to implement transmission circuit, and/or the low voltage sides of the transformers are electrically connected.

An apparatus can comprise a circuit and an electrical element coupled to the circuit. The circuit can include a pulse generator to generate an electrical pulse having a first power and a load. The electrical element can be configured to receive heat that is converted into electrical energy by the circuit to apply a second power, greater than the first power, to the load.

An apparatus can comprise a circuit and an electrical element coupled to the circuit. The circuit can include a pulse generator to generate an electrical pulse having a first power and a load. The electrical element can be configured to receive heat that is converted into electrical energy by the circuit to apply a second power, greater than the first power, to the load.

Some embodiments of the invention include a pre-pulse switching system. The pre-pulsing switching system may include: a power source configured to provide a voltage greater than 100 V; a pre-pulse switch coupled with the power source and configured to provide a pre-pulse having a pulse width of T.sub.pp; and a main switch coupled with the power source and configured to provide a main pulse such that an output pulse comprises a single pulse with negligible ringing. The pre-pulse may be provided to a load by closing the pre-pulse switch while the main switch is open. The main pulse may be provided to the load by closing the main switch after a delay T.sub.delay after the pre-pulse switch has been opened.

Some embodiments of the invention include a pre-pulse switching system. The pre-pulsing switching system may include: a power source configured to provide a voltage greater than 100 V; a pre-pulse switch coupled with the power source and configured to provide a pre-pulse having a pulse width of T.sub.pp; and a main switch coupled with the power source and configured to provide a main pulse such that an output pulse comprises a single pulse with negligible ringing. The pre-pulse may be provided to a load by closing the pre-pulse switch while the main switch is open. The main pulse may be provided to the load by closing the main switch after a delay T.sub.delay after the pre-pulse switch has been opened.