Abstract: A camper system is configurable between folded and expanded arrangements. The camper system includes a base frame, a floor substantially rigidly mounted to the base frame, a base wall rigidly coupled with the floor, substantially perpendicular thereto and having interior surfaces and exterior surfaces. First and second flanges project from the floor substantially perpendicular thereto and intersect at least one of the base wall interior surfaces. A first shell is pivotably coupled with the base wall along a first pivot axis. A second shell is pivotably coupled with the base wall along a second pivot axis parallel with the first pivot axis. A third shell is pivotably coupled with the base wall along a third pivot axis perpendicular to the first and second pivot axes. A fourth shell is pivotably coupled with the first and second flanges along a fourth pivot axis parallel with the third pivot axis.

Abstract: A camper system is configurable between folded and expanded arrangements. The camper system includes a base frame, a floor substantially rigidly mounted to the base frame, a base wall rigidly coupled with the floor, substantially perpendicular thereto and having interior surfaces and exterior surfaces. First and second flanges project from the floor substantially perpendicular thereto and intersect at least one of the base wall interior surfaces. A first shell is pivotably coupled with the base wall along a first pivot axis. A second shell is pivotably coupled with the base wall along a second pivot axis parallel with the first pivot axis. A third shell is pivotably coupled with the base wall along a third pivot axis perpendicular to the first and second pivot axes. A fourth shell is pivotably coupled with the first and second flanges along a fourth pivot axis parallel with the third pivot axis.

Abstract: A training apparatus for improving the performance of a swimmer. In a first aspect of the invention, a propeller rotates about an axis which is aligned with the path of the swimmer. A permanent magnet driven by the propeller attached to the swimmer produces a rotating magnetic field which acts on a magnetic field transducer to produce a pulsating signal whose frequency varies directly with the swimmer's speed. The sensor's output is multiplied, amplified and fed to an earphone worn by the swimmer. Changes in frequency immediately inform the swimmer of whether his performance has improved or deteriorated.In a second aspect of the invention, permanent magnets are mounted on vanes of an impeller which rotate about a horizontal axis which is at right angles to the path of the swimmer. Rotating magnetic fields of the permanent magnets act on a magnetic field sensor to produce a pulsating signal whose frequency varies with the swimmer's speed.

Abstract: A battery-operated fluid level monitor has a novel circuit and sensor for providing signals, both audible and visible, for indicating low fluid level, low battery voltage, and proper fluid level. The monitor is useful as a device that can inform when a Christmas tree needs water. The monitor can also be economically fabricated, and this is important for mass production applications, such as a Christmas tree monitor.

Abstract: A tire pressure sensing system for on-board use in an automotive vehicle comprises a transmitter mounted to rotate with each tire and a receiver that is disposed in sensing relationship to each transmitter. Each receiver is a Hall Effect sensor. Each transmitter comprises three magnetic poles that are effective to cause the Hall Effect sensor to develop a bi-directional pulse waveform during passage of the transmitter past the receiver. Electronic circuitry processes the signal waveform that is created by the Hall Effect sensor in response to passage of the magnetic poles. The circuitry develops one rectangular pulse waveform from one magnetic polarity and another rectangular pulse waveform from the other magnetic polarity.

Abstract: A method and system for delaying mechanical loading of an internal combustion engine by an alternator during start-up and transitional phases of the engine by inhibiting the field winding current of the alternator until the engine reaches a predetermined operational condition for a continuous predetermined period of time.