Abstract: Disclosed herein is a communications system implementing a microphone wirelessly connected to a half-duplex communications device, such as a two-way radio or a radio-simulating cellular phone. The microphone may incorporate a transmit/receive switch wherein a transmit signal is wirelessly transmitted from the microphone to the communications device to direct the communications device to enter into a transmit mode. The microphone may communicate with the half-duplex communications device through a magnetic induction link.

Abstract: Disclosed herein is a communications system implementing a headset wirelessly connected to a half-duplex communications device, such as a two-way radio or a radio-simulating cellular phone. The headset may incorporate a transmit/receive switch wherein a transmit signal is wirelessly transmitted from the headset to the communications device to direct the communications device to enter into a transmit mode. Alternatively, a wireless transmit/receive switch may be implemented separately from the wireless headset, where the wireless transmit/receive switch may be positioned in the proximity of the communications device and the headset and may be engaged by a user to direct the communications device to enter a transmit mode.

Abstract: An air turbine apparatus is suitable for use as the intake or exhaust of a combustion engine. A housing defines an expansion chamber that communicates with an inlet and outlet. A tube is disposed proximate to the inlet and includes a plurality of perforations to encourage air flow from the expansion chamber to an induction chamber within the tube.

Abstract: An air turbine apparatus for use with a combustion engine either as a muffler or as an air intake device is comprised of a housing defining an expansion chamber and an airfoil positioned within the housing. The airfoil includes a central aperture extending longitudinally therethrough that is in fluid communication with both the inlet and the outlet of the housing. The airfoil is configured to allow gases flowing through the inlet to flow between the outer edge of the airfoil and the housing and through the aperture of the airfoil. In addition, the air traveling through the housing is caused to spin as it travels through the housing. This rotational flow increased the rate of flow of gases through the air turbine device. A chop core is provided between the airfoil and the outlet of the housing to encourage turbulent flow of gases without restricting flow to produce a muffling effect and thus a dampening of noise from the combustion engine.

Abstract: An air turbine apparatus for use with a combustion engine either as a muffler or as an air intake device is comprised of a housing defining an expansion chamber and an airfoil positioned within the housing. The airfoil includes a central aperture extending longitudinally therethrough that is in fluid communication with both the inlet and the outlet of the housing. The airfoil is configured to allow gases flowing through the inlet to flow between the outer edge of the airfoil and the housing and through the aperture of the airfoil. In addition, the air traveling through the housing is caused to spin as it travels through the housing. This rotational flow increased the rate of flow of gases through the air turbine device. A chop core is provided between the airfoil and the outlet of the housing to encourage turbulent flow of gases without restricting flow to produce a muffling effect and thus a dampening of noise from the combustion engine.