Abstract: A surge protection module comprises a base, a plurality of first pins extending from the base to connect electrically to an upstream circuit, a plurality of second pins extending from the base to connect electrically to a downstream circuit, a fuse device acting between each first pin and a respective one of the second pins, at least one analog arrestor upstream of the fuse devices that is electrically connected across the first pins and in electrical connection to a ground terminal extending from the base, and a low capacitance solid state arrestor arrangement electrically connected to each second pin downstream of the fuse devices and to the ground terminal.

Abstract: A surge protection module comprises a base, a plurality of first pins extending from the base to connect electrically to an upstream circuit, a plurality of second pins extending from the base to connect electrically to a downstream circuit, a fuse device acting between each first pin and a respective one of the second pins, at least one analog arrestor upstream of the fuse devices that is electrically connected across the first pins and in electrical connection to a ground terminal extending from the base, and a low capacitance solid state arrestor arrangement electrically connected to each second pin downstream of the fuse devices and to the ground terminal.

Abstract: A method and apparatus for measuring the depth of fluid in a well and for controlling the speed of a pump which pumps fluid out of the well according to the measured depth is disclosed. The depth of fluid in a well is measured by sending an acoustic pulse into an annulus between the well casing and the production tubing and sensing reflections of the acoustic pulse from collars on the tubing and a reflection from the fluid surface. Since the collar spacing on the production tubing is known, the distance from the top of the well to the surface of the fluid can be obtained by accumulating the distance associated with the collars detected in the reflection signal. The collar reflections are sensed by converting the reflected acoustic wave into electrical signals and then amplitude demodulating the broadband electrical signals.

Abstract: A protector for use in a telecommunications system to establish an electrical connection between two lines includes a base and at least two line terminals extending from one surface of the base. A ground terminal also extends from the one surface of the base and is spaced from the two line terminals. A circuit board is mounted on another surface of the base and has electrical paths on it leading to the at least two line terminals and to the ground terminal. An overload detector is mounted on the circuit board and establishes an electrical connection between the at least two line terminals by way of the electrical paths in normal operation and establishes an electrical connection between at least one of the at least two line terminals and the ground terminal by way of the electrical paths in the event of an overload condition.