A method and a device are provided for monitoring an electrical power supply network. A temporal frequency change value is determined for at least two sections or for at least two points of the power supply network. The frequency change value indicates the respective temporal frequency change of the network frequency. A conclusion is drawn regarding a possible islanding within the power supply network, and a warning signal which indicates the possible islanding within the power supply network is generated when the difference between the frequency change values, exceeds a predetermined frequency change threshold value.

A method and a device are provided for monitoring an electrical power supply network. A temporal frequency change value is determined for at least two sections or for at least two points of the power supply network. The frequency change value indicates the respective temporal frequency change of the network frequency. A conclusion is drawn regarding a possible islanding within the power supply network, and a warning signal which indicates the possible islanding within the power supply network is generated when the difference between the frequency change values, exceeds a predetermined frequency change threshold value.

A digital oscilloscope comprises a sampling unit configured to sample an input signal received from an oscilloscope probe to produce a first stream of digital samples, a first acquisition system configured to store and process the stream of digital samples to produce a first data set, a second acquisition system configured to store and process the first stream of digital samples independent of the first acquisition system to produce a second data set, and a display system configured to concurrently display the first data set in a first format and the second data set in a second format different from the first format.

An apparatus is described that receives a brake control signal from the brake controller of a tow vehicle, and displays characteristics of that brake control signal including commanded brake force. The apparatus includes a data processor, brake simulation circuitry, brake integration circuitry, and display circuitry. The brake simulation circuitry sequentially applies several parallel resistors to the brake control signal in response to commands received from the data processor. These parallel resistors cause the load current on the brake controller to ramp up, mimicking the electrical signature of electric trailer brakes. At the same time, the brake integration circuitry integrates the brake control signal. Lastly, the display circuitry displays an indication of a value of the integrated brake control signal.

Disclosed herein is an exceptional points of degeneracy (EPD) system with a resonator by introducing a linear time-periodic variation. In contrast, prior art systems with EPD require two coupled resonators with precise values of gain and loss and a precise symmetry of inductances and capacitances. The disclosed EPD system only requires the tuning of the modulation frequency or modulation depth, which can be easily achieved in electronic systems. The EPD is a point in a system parameters' space at which two or more eigenstates coalesce, and this leads to unique properties not occurring at other non-degenerate operating points. Also disclosed are experimental data showing the existence of a second order EPD in a time-varying single resonator and the expected sensitivity of its resonances to circuit perturbations. The disclosed EPD system exhibits structural degenerate and non-degenerate resonances whose dynamics dramatically boosts its sensitivity performance to very small perturbations. The unique sensitivity induced by an EPD can be employed to create exceptionally-sensitive sensors based on a resonator by simply applying time modulation.

Disclosed herein is an exceptional points of degeneracy (EPD) system with a resonator by introducing a linear time-periodic variation. In contrast, prior art systems with EPD require two coupled resonators with precise values of gain and loss and a precise symmetry of inductances and capacitances. The disclosed EPD system only requires the tuning of the modulation frequency or modulation depth, which can be easily achieved in electronic systems. The EPD is a point in a system parameters' space at which two or more eigenstates coalesce, and this leads to unique properties not occurring at other non-degenerate operating points. Also disclosed are experimental data showing the existence of a second order EPD in a time-varying single resonator and the expected sensitivity of its resonances to circuit perturbations. The disclosed EPD system exhibits structural degenerate and non-degenerate resonances whose dynamics dramatically boosts its sensitivity performance to very small perturbations. The unique sensitivity induced by an EPD can be employed to create exceptionally-sensitive sensors based on a resonator by simply applying time modulation.

An improved counter may implement dynamic frequency measurement while also remaining fully backwards compatible with traditional frequency measurement methods. The counter may operate according to low-frequency, large range, and/or high frequency modes of operation. It may be programmable with a divisor value associated with the large range operating mode, and a measurement time associated with the high frequency mode of operation. The divisor and measurement time settings may be enabled or disabled, and when either setting is disabled, the counter becomes backwards compatible with traditional frequency measurement methods. The counter may also be provided with inputs representative of the desired type of measurement and the minimum and maximum expected values for the signal to be measured. The counter may perform the frequency measurement according to any one or more of the operating modes, and return a measurement result obtained in the operating mode that completes the measurement first.

An improved counter may implement dynamic frequency measurement while also remaining fully backwards compatible with traditional frequency measurement methods. The counter may operate according to low-frequency, large range, and/or high frequency modes of operation. It may be programmable with a divisor value associated with the large range operating mode, and a measurement time associated with the high frequency mode of operation. The divisor and measurement time settings may be enabled or disabled, and when either setting is disabled, the counter becomes backwards compatible with traditional frequency measurement methods. The counter may also be provided with inputs representative of the desired type of measurement and the minimum and maximum expected values for the signal to be measured. The counter may perform the frequency measurement according to any one or more of the operating modes, and return a measurement result obtained in the operating mode that completes the measurement first.

An apparatus and a method of determining a frequency of an AC power source that more accurately determine the frequency of the AC power source connected to a vehicle are provided. The apparatus includes a rectifier that is connected to the AC power source to rectify an AC voltage input from the AC power source, a first filter connected to an output terminal of the rectifier to filter a rectified voltage output by the rectifier and a second filter connected to the output terminal of the rectifier to filter the rectified voltage output by the rectifier. Further, a frequency determination unit configured to receive the rectified voltages that pass through the first and second filters and determine a voltage frequency of the AC power source from the rectified voltage that pass through the first filter using the rectified voltage that pass through the second filter as a frequency determination level.

An apparatus and a method of determining a frequency of an AC power source that more accurately determine the frequency of the AC power source connected to a vehicle are provided. The apparatus includes a rectifier that is connected to the AC power source to rectify an AC voltage input from the AC power source, a first filter connected to an output terminal of the rectifier to filter a rectified voltage output by the rectifier and a second filter connected to the output terminal of the rectifier to filter the rectified voltage output by the rectifier. Further, a frequency determination unit configured to receive the rectified voltages that pass through the first and second filters and determine a voltage frequency of the AC power source from the rectified voltage that pass through the first filter using the rectified voltage that pass through the second filter as a frequency determination level.