Abstract: Solid state power controllers are described that include a switch controlled by a microcontroller and communication contacts. In one aspect of the invention, the microcontroller is galvanically isolated from the communication contacts using magnetoresistive isolation. In another aspect of the invention a number of solid state power controllers are connected to an external microcontroller to form a power distribution array. In addition, messages exchanged between the external microcontroller and the solid state power controllers can be used to configure the solid state power controllers and provide a user interface.

Abstract: Solid state power controllers are described that include a switch controlled by a microcontroller and communication contacts. In one aspect of the invention, the microcontroller is galvanically isolated from the communication contacts using magnetoresistive isolation. In another aspect of the invention a number of solid state power controllers are connected to an external microcontroller to form a power distribution array. In addition, messages exchanged between the external microcontroller and the solid state power controllers can be used to configure the solid state power controllers and provide a user interface.

Abstract: Solid state power controllers in various configurations are provided. One such solid state power controller includes a power connector, a load connector and at least one communication connector, a solid state switch electrically connectable between the power connector and the load connector, where the switch includes an input, a microcontroller coupled to the input of the solid state switch, and current sensing circuitry coupled to the microcontroller and configured to sense a current flowing through the solid state switch, the current sensing circuitry including an amplifier having an offset error, where the current sensing circuitry is configured to generate a signal indicative of the current flowing through the solid state switch, and bias the generated signal to a predetermined level to substantially eliminate the offset error in the amplifier.

Abstract: Solid state power controllers are described that include a switch controlled by a microcontroller and communication contacts. In one aspect of the invention, the microcontroller is galvanically isolated from the communication contacts using magnetoresistive isolation. In another aspect of the invention a number of solid state power controllers are connected to an external microcontroller to form a power distribution array. In addition, messages exchanged between the external microcontroller and the solid state power controllers can be used to configure the solid state power controllers and provide a user interface.

Abstract: Solid state power controllers are described that include a switch controlled by a microcontroller and communication contacts. In one aspect of the invention, the microcontroller is galvanically isolated from the communication contacts using magnetoresistive isolation. In another aspect of the invention a number of solid state power controllers are connected to an external microcontroller to form a power distribution array. In addition, messages exchanged between the external microcontroller and the solid state power controllers can be used to configure the solid state power controllers and provide a user interface.

Abstract: Solid state power controllers are described that include a switch controlled by a microcontroller and communication contacts. In one aspect of the invention, the microcontroller is galvanically isolated from the communication contacts using magnetoresistive isolation. In another aspect of the invention a number of solid state power controllers are connected to an external microcontroller to form a power distribution array. In addition, messages exchanged between the external microcontroller and the solid state power controllers can be used to configure the solid state power controllers and provide a user interface.

Abstract: A vibration densitometer having a permanent magnet biased magnetostrictive drive unit, a maximum efficiency, and an automatic search for a resonant frequency signal.

Abstract: A vibration densitometer having a magnetostrictive drive with a coil, and a crystal pick-up. A loop circuit including a driver amplifier provides the coil with current which leads the crystal voltage by 90 degrees for maximum efficiency. The driver amplifier is unusually small, inexpensive and accurate.

Abstract: A net oil computer including a mean density electric current source that alternately supplies all of or a portion of water density and oil density electric currents with the differences between the mean and water currents and between the mean and oil currents alternately charging and discharging a capacitor between two different voltage levels or vice versa. A bistable circuit switches the capacitor to charge and discharge when the capacitor voltage reaches the respective two different levels. One or both of the capacitor charging and discharging periods may then be used to gate turbinemeter pulses, the number of which is proportional to total oil flow and/or total water flow in a pipeline.

Abstract: A vibration densitometer having a magnetostrictive drive with a coil and a crystal pickup. A loop circuit including a driver amplifier provides the coil with a voltage twice that ordinarily provided. Further, the driver amplifier is unusually small, inexpensive and accurate.

Abstract: A vibration densitometer having a magnetostrictive drive with a coil, and a crystal pick-up. A loop circuit including a driver amplifier provides the coil with current which leads the crystal voltage by 90 degrees for maximum efficiency.