A method for maintaining an actuator for an airbag control device. The method has a step of impressing an electric current flow through the actuator using an electric voltage having a voltage value. In addition, the method has a step of ascertaining an electric measuring current through the actuator. Here, the electric measuring current through the actuator occurs on account of the impressed electric current flow through the actuator. In addition, the method has a step of executing a comparison of the electric measuring current through the actuator to a threshold value. Moreover, the method has a step of adjusting the voltage value of the electric voltage for impressing the electric current flow through the actuator as a function of the comparison.

A device for monitoring an operation of an inductive element, includes a current-measuring device is switched in series with the inductive element. The device is configured to ascertain a first time-discrete and value-discrete signal, which characterizes a current flowing through the current-measuring device; to ascertain a second time-discrete and value-discrete signal, which characterizes a current flowing through the current-measuring device and has a predefinable time shift in relation to the first signal; and to infer the presence of a shunt from a comparison of the first signal with the second signal. Also described is a method for monitoring the operation of the inductive element.

A solenoid is determined abnormal if a current flowing therethrough at a certain duty ratio falls within an abnormal range. After the abnormal determination, a first duty ratio is used to cause a current to flow through the solenoid at such a current value within a first range as to not drive the solenoid valve. The solenoid is determined provisionally normal if the current at the first duty ratio falls within the first range. After the provisionally normal determination, a second duty ratio is used to cause a current to flow through the solenoid at such a current value within a second range including a current value range greater than the first range as to drive the solenoid valve. The solenoid is determined normal if the current at the second duty ratio falls within the second range.

Method for detecting short-circuits in a coil in an electric machine, includes: a) arranging a coil in an air gap between the rotor and stator; c) recording signal curves generated by the coil; d) determining zero crossings of the curve and storing the times thereof; e) determining zero crossings of the curve corrected by an offset c, identifying a pair of immediately consecutive zero crossings, the time separation of which is longer than the minimum duration; f) in no pair is identified, repeating step e) until identified, wherein the offset c is varied from the zero point to a global extreme value of the curve; g) identifying at least one of the two stored times, which lies between and closest in time to the pair and; h) extracting two half-waves from the curve using times identified in step g), wherein each half-wave corresponds to half a revolution of the rotor.

An apparatus that includes a power amplifier; a load that is operatively connected to be electrically driven from the power amplifier; and an impedance monitor that is configured to in real-time identify a favorable segment within an output waveform of the power amplifier, model the baseline power spectral density of a load driven by the power amplifier during the identified segment of the output waveform, sample an empirical power spectral density of the load during the identified segment of the output waveform, and indicate a load fault in the event that the empirical power spectral density deviates from the baseline power spectral density beyond at least one pre-determined error criteria.

A system for on-line bushing monitoring and geo-magnetically induced current monitoring utilizes a Hall Effect current transducer and obtains the harmonic component of the signals through the measurement of bushing test tap current which provides a more reliable measurement method since the bushings provide a capacitive voltage divider that is not subject to saturation which is a drawback of using current transformers to obtain the signals. The system combines the existing harmonic analysis functions of the bushing monitor measurement system with the measured neutral direct current to provide an economical and efficient system that monitors both bushing condition and GIC conditions with one common monitoring module.

A system for the verification of the absence of voltage includes a first impedance, an amplitude limiter electrically connected to the first impedance, a second impedance electrically connected to the first impedance and the amplitude limiter, a varactor circuit electrically connected to the second impedance, an isolation capacitor electrically connected to the second impedance and varactor circuit, an envelope circuit with a voltage detection circuit connected to the isolation circuit via a buffer, and an RF oscillator. The amplitude limiter configured to limit the voltage applied to the varactor circuit. The RF oscillator configured to interact with the varactor circuit in order to create a modulated circuit for the buffer and envelope circuit. The envelope circuit is configured to demodulate the signal for the voltage detection circuit.

A method and an apparatus check a multiplicity of mutually insulated strands in a stator winding bar of an electric machine. The method includes injecting a test signal, determining a first component of the test signal, and comparing at least the first component with a reference signal in order to determine damage to insulation between individual strands of the multiplicity of strands. The apparatus includes a signal source and a measuring apparatus. The method and the apparatus are particularly suitable for checking stator winding bars as are used in a generator and/or an electric motor.

An apparatus and a method for detecting a dielectric breakdown in an eco-friendly vehicle are provided. The apparatus includes a measurer that is configured to measure resistance values of insulation resistors disposed across a high voltage battery and a controller that is configured to measure a voltage applied to the insulation resistor using the measurer and analyze a pattern of the measured voltage to detect a dielectric breakdown portion.

An apparatus and method of detecting movement of a plunger of the solenoid includes detecting a peak (I.sub.PEAK) in a current signal applied to a coil of the solenoid. A predetermined threshold is added to the current signal applied to the coil of the solenoid to generate a level shifted signal. The level shifted signal and the peak signal are compared to detect movement of a plunger of the solenoid.