The invention provides an in-line power monitor for an RF transmission line that is capable of being calibrated in-line during live conditions at the exact power level and frequency where it is used. This device uses forward and reflected directional couplers and a non-directional coupler to sample the RF voltage on the transmission line. The RF voltage of the forward and reflected channels are each split into two paths, one going to a test port and the other leading to additional circuitry which prepares the signals of the forward and reflected channels for output to power displays. Additionally, the monitor allows the user to compensate for any voltage offsets introduced by various circuitry components. Further, the monitor also allows to user to individually calibrate the output of the forward and reflected channels by applying an adjustable gain ratio correction to each channel.

Various embodiments include methods and apparatus structured to balance electrode pairs (112, 312) of a tool (105, 305) providing voltage equivalence between the electrode pairs. An electrically conductive wire (113, 313) coupling the electrodes of an electrode pair can be arranged such that resistance of the electrically conductive wire does not adversely affect the voltage equivalence. The electrically conductive wire can also be structured to provide temperature independent balancing by arranging the electrically conductive wire with respect to a measuring node (116, 316). Additional apparatus, systems, and methods are disclosed.

A large-caliber telescope non-linear interference detecting and filtering method is provided. The measure of the oil pad interference is accomplished with one of the following two methods, accelerometer and encoder, or using both of the said methods simultaneously. The filtering of the oil pad interference: set a NOTCH frequency as the main interfering frequency by using NOTCH filter to filter the interference and distinctly improve the telescope performance. The telescope and method is specific to a large-caliber telescope with an oil pad, by using an acceleration sensor and an encoder to precisely measure the non-linear interfering frequency of the telescope oil pad system, by using a NOTCH digital filter to accurately filter the interference due to the oil pad system, and through adjusting parameters of the digital filter to change the filter frequency band on the basis of the change of the oil pad interfering frequency.

A large-caliber telescope non-linear interference detecting and filtering method is provided. The measure of the oil pad interference is accomplished with one of the following two methods, accelerometer and encoder, or using both of the said methods simultaneously. The filtering of the oil pad interference: set a NOTCH frequency as the main interfering frequency by using NOTCH filter to filter the interference and distinctly improve the telescope performance. The telescope and method is specific to a large-caliber telescope with an oil pad, by using an acceleration sensor and an encoder to precisely measure the non-linear interfering frequency of the telescope oil pad system, by using a NOTCH digital filter to accurately filter the interference due to the oil pad system, and through adjusting parameters of the digital filter to change the filter frequency band on the basis of the change of the oil pad interfering frequency.

A method and apparatus for estimating current is disclosed. The current estimation apparatus may receive a voltage value of a battery pack and voltage values of cells included in the battery pack, and may estimate a current of the battery pack based on the voltage value of the battery pack, the voltage values of the cells included in the battery pack, and resistance components within the battery pack.

A method and apparatus for estimating current is disclosed. The current estimation apparatus may receive a voltage value of a battery pack and voltage values of cells included in the battery pack, and may estimate a current of the battery pack based on the voltage value of the battery pack, the voltage values of the cells included in the battery pack, and resistance components within the battery pack.

Methods, apparatus, systems and articles of manufacture to trigger calibration of a sensor node using machine learning are disclosed. An example apparatus includes a machine learning model trainer to train a machine learning model using first sensor data collected from a sensor node. A disturbance forecaster is to, using the machine learning model and second sensor data, forecast a temporal disturbance to a communication of the sensor node. A communications processor is to transmit a first calibration trigger in response to a determination that a start of the temporal disturbance is forecasted and a determination that a first calibration trigger has not been sent.

The disclosure relates to accurately determining a DC energy signal, such as a DC current or DC voltage, which may be particularly useful when controlling a formation/testing current of a battery cell during formation and/or testing. In the battery formation/testing context, a current sensor is used to measure the current of the battery cell, which is used as a feedback signal for controlling the current to achieve a target current. The transfer function of the current sensor is used to improve the accuracy of the current measurement. Because the transfer function can be regularly determined during formation/testing, a lower-cost current sensor with relatively poor temperature coefficient may be used. Any change in the gain of the current sensor may be detected by the transfer function determination and corrected for. Therefore, high current control accuracy may be achieved at lower cost.

An apparatus is provided that can estimate a transfer function, for example of current measurement systems, voltage measurement systems and power measurement systems, and also provide an estimate of certainty about the transfer function. This enables customers to have confidence that they are not being overcharged for electricity.

An apparatus is provided that can estimate a transfer function, for example of current measurement systems, voltage measurement systems and power measurement systems, and also provide an estimate of certainty about the transfer function. This enables customers to have confidence that they are not being overcharged for electricity.