Abstract: Apparatus and methods are described for identifying desired data recorded in a magnetic media based on the density in which the data is recorded in the media. In one embodiment the invention includes a first magnetic reading head connected to a first intermediate network, a second magnetic reading head connected to a second intermediate network and a logic unit connected to the first and second intermediate networks, where the logic unit is configured to compare the rates at which flux transitions occur at the first and second reading heads.

Abstract: The present invention provides a battery system, a device, and a method to allow multiple batteries with varying capacities and power capabilities to drive a common load. Furthermore, the present invention provides a method for adjusting the output current of one or more of the batteries driving a common load to maximize the operational time of the load. The level of the current being supplied by the battery unit is monitored and compared to a desired current level. Upon detecting a change in the level of the current, the output voltage of one or more of the battery systems is modified to return the level of the battery current to the desired current level. This is accomplished by detecting the battery current (31) with a detector (66) and transforming the change in the battery current into an error signal (76) by comparing a voltage, representative of the battery current (31) with a reference value (72). The error signal (76) is then converted into an output adjust signal (62) by an adjuster (78).

Abstract: A remote control transmitter/receiver system wherein an absolute direction command may be issued by the transmitter and acted upon by the receiver. The transmitter and receiver both include a common reference direction so that an absolute direction command (i.e., relative to the common reference direction) may be issued and acted upon. In a preferred embodiment, the transmitter operates in accordance with an internal compass signal so that an absolute direction command relative to magnetic North can be generated by the transmitter. The receiver also functions in accordance with an internal compass signal so that an absolute direction command transmitted to the receiver can be effected. The transmitter and receiver may be microprocessor controlled, and the internal compass signal may be generated with an electronic flux gate compass. The invention may be used in place of the conventional remote control systems that are used with hand-held transmitters and hobby vehicles.

Abstract: To simulate, for testing purposes, the subsystems of an aircraft that electrohydraulically position the movable control surfaces of an aircraft, circuitry is provided for receiving input control signals, generated, for example, by an autopilot, and for transforming such signals into electrical output signals that are the analogs of signals produced by linear variable differential transformers (LVDT) feedback devices that track the actual movements and positions of the aircraft control surfaces. The relatively slow acting hydraulic components of the aircraft control subsystems are simulated by integrating circuitry and the resulting integrated signals are used to modulate an AC reference signal, which is then applied to the primaries of isolation transformers, the secondaries of which produce the simulated, analog LVDT feedback signals and also present a load impedance to the autopilot that closely matches the output windings of the simulated LVTDs.