Abstract: A system includes a first sense circuit configured to provide a first output representative of sensed current provided by a first battery coupled to a first load. A second sense circuit is configured to provide a second output representative of sensed current provided by a second battery coupled to the first load. An input current controller is coupled to receive the respective first and second outputs and to couple between the second battery and the first load to control the current provided by the second battery.

Abstract: The present disclosure relates to the field of oilfield plugging agents, and in particular to a plugging agent for oil extraction in an oilfield and a preparation method therefor and an application thereof.

Abstract: The present disclosure relates to the technical field of oilfield chemicals, and discloses an acrylamide copolymer, wherein the acrylamide copolymer comprises a structural unit A, a structural unit B and a structural unit C, wherein the structural unit A has a structure shown in Formula (1), the structural unit B has a structure shown in Formula (2), and the structural unit C has a structure shown in Formula (3) and/or Formula (4); wherein R1 is methyl or H, R2 is —OH, —NH2, —COOH or C2-C12 alkyl, n is an integer between 0 and 6, and a, b and c are each independently selected from integers between 0 and 2.

Abstract: A system includes a first sense circuit configured to provide a first output representative of sensed current provided by a first battery coupled to a first load. A second sense circuit is configured to provide a second output representative of sensed current provided by a second battery coupled to the first load. An input current controller is coupled to receive the respective first and second outputs and to couple between the second battery and the first load to control the current provided by the second battery.

Abstract: A system and method generate an alternating current (AC) input signal by a digitally controlled resonant drive circuit. The method includes driving a face tracking sensor with the input signal. An output signal is received from the face tracking sensor and an amplitude of the output signal is compared to a target amplitude. A duty cycle of the resonant drive circuit is modified based on the comparison to control the amplitude of the output signal about the target amplitude.

Abstract: The disclosed techniques provide a number of technical benefits by providing a bridge sensor DC error cancellation scheme. In one embodiment, a system includes a piezoresistive Wheatstone bridge, a number of switches, and a non-overlapping clock. The system can mitigate noise and other errors by subtraction of the two differential outputs of the system between a first phase and a second phase of a clock input controlling the switches. In some embodiments, the system can also include differential programmable gain amplifiers and a multi-bit analog-to-digital converter. By providing a bridge sensor DC error cancellation scheme for producing an analog output, a system can be used to generate a stable digital output of at the analog-to-digital converter.

Abstract: The present disclosure relates to the technical field of oilfield chemicals, and discloses an acrylamide copolymer, wherein the acrylamide copolymer comprises a structural unit A, a structural unit B and a structural unit C, wherein the structural unit A has a structure shown in Formula (1), the structural unit B has a structure shown in Formula (2), and the structural unit C has a structure shown in Formula (3) and/or Formula (4); wherein R1 is methyl or H, R2 is —OH, —NH2, —COOH or C2-C12 alkyl, n is an integer between 0 and 6, and a, b and c are each independently selected from integers between 0 and 2.