A system for monitoring electrical current leakage comprises a frequency injection circuit, one or more devices, and a microprocessor. The frequency injection circuit includes an electronic oscillator providing an electrical signal to a first side of an isolation barrier. The devices are located on a second side of the isolation barrier. The microprocessor samples the electrical signal and identifies deviations in the sampled electrical signal exceeding a predetermined threshold caused by the one or more devices. The microprocessor further generates one or more alert messages based on the identified deviations in the electrical signal.

A system for monitoring electrical current leakage comprises a frequency injection circuit, one or more devices, and a microprocessor. The frequency injection circuit includes an electronic oscillator providing an electrical signal to a first side of an isolation barrier. The devices are located on a second side of the isolation barrier. The microprocessor samples the electrical signal and identifies deviations in the sampled electrical signal exceeding a predetermined threshold caused by the one or more devices. The microprocessor further generates one or more alert messages based on the identified deviations in the electrical signal.

An RF generator includes: a modulation circuit outputting a pulsed RF signal; a variable attenuation circuit adjusting the level of the pulsed RF signal; an output power detecting unit detecting an output power value of the power output from the device; a first comparative arithmetic circuit outputting a first level control signal for controlling the level of the adjusted pulsed RF signal on the basis of a first detected voltage value and a set voltage value set in advance; a second comparative arithmetic circuit outputting a second level control signal for controlling the level of the adjusted pulsed RF signal on the basis of a second detected voltage value and the set voltage value; and a switching circuit switching between the value of the first level control signal and the value of the second level control signal depending on a switching timing setting value.

An RF generator includes: a modulation circuit outputting a pulsed RF signal; a variable attenuation circuit adjusting the level of the pulsed RF signal; an output power detecting unit detecting an output power value of the power output from the device; a first comparative arithmetic circuit outputting a first level control signal for controlling the level of the adjusted pulsed RF signal on the basis of a first detected voltage value and a set voltage value set in advance; a second comparative arithmetic circuit outputting a second level control signal for controlling the level of the adjusted pulsed RF signal on the basis of a second detected voltage value and the set voltage value; and a switching circuit switching between the value of the first level control signal and the value of the second level control signal depending on a switching timing setting value.

Aspects of this disclosure relate to reducing settling time of a sawtooth ramp signal in a phase-locked loop. Information from a loop filter of the phase-locked loop can be stored and used within the loop filter so as to improve the settling time of the sawtooth ramp signal. In certain embodiments, the settling time of a periodic sawtooth ramp signal can be reduced to less than one microsecond. An output frequency at the end of the sawtooth chirp can be brought back to an initial value without significantly modifying phase error in disclosed embodiments.

Aspects of this disclosure relate to reducing settling time of a sawtooth ramp signal in a phase-locked loop. Information from a loop filter of the phase-locked loop can be stored and used within the loop filter so as to improve the settling time of the sawtooth ramp signal. In certain embodiments, the settling time of a periodic sawtooth ramp signal can be reduced to less than one microsecond. An output frequency at the end of the sawtooth chirp can be brought back to an initial value without significantly modifying phase error in disclosed embodiments.

The present invention relates to an electromagnetic acoustic transducer excitation system comprising a tone burst generator, the tone burst generator comprising: an oscillator device configured to produce a radio frequency signal; an analog switch configured to produce an output based on the radio frequency signal produced by the oscillator device and a control signal; a pre-amplifier configured to amplify the output of the analog switch and produce a tone burst output signal; and a control module configured to produce the control signal for providing to the analog switch.

The present invention relates to an electromagnetic acoustic transducer excitation system comprising a tone burst generator, the tone burst generator comprising: an oscillator device configured to produce a radio frequency signal; an analog switch configured to produce an output based on the radio frequency signal produced by the oscillator device and a control signal; a pre-amplifier configured to amplify the output of the analog switch and produce a tone burst output signal; and a control module configured to produce the control signal for providing to the analog switch.

Disclosed are non-linear transmission lines using ferromagnetic materials to generate ferromagnetic resonance oscillations. In one aspect, a non-linear transmission line apparatus is disclosed. The apparatus includes an outer conductor having a first side and a second internally facing side, and an inner conductor positioned internal to the non-linear transmission line apparatus. The apparatus further includes a ferromagnetic material surrounding the inner conductor, wherein the ferromagnetic material comprises nanoparticles of an ?-polymorph of iron oxide expressed as ?-Fe.sub.2O.sub.3. The apparatus also includes a first dielectric material positioned between the outer conductor and the inner conductor, the dielectric material in contact with both the ferromagnetic material and with the second internally facing side of the outer conductor, wherein the outer conductor, the inner conductor, the dielectric material and the ferromagnetic material form the nonlinear transmission line.

A gate drive circuit includes a lower limit clamping circuit, an upper limit clamping circuit, and an averaging circuit. The lower limit clamping circuit clamps the input node of a transistor at a minimum voltage with respect to the common node of the transistor, while the upper limit clamping circuit clamps the input node of the transistor at a maximum voltage with respect to the common node of the transistor and the averaging circuit sets the average voltage of the input node with respect to the common node over a specified period of time. The transistor including a common node, an output node and an input node receives the input signal. Controlling the upper limit, lower limit and average value in conjunction with fast transitions between the lower and upper limits controls the duty cycle of the input signal.