An automatic tensioner having a load cell for detecting and controlling a power transmission belt tension. The tensioner comprises a lead screw driven by an electric motor for setting a lever arm/pulley position and thereby a belt load. The tensioner also comprises a load cell engaged with a tensioner lead screw for detecting a belt load. The tensioner motor is controlled loop using a load cell signal. The controller compares a detected belt load from the load cell with a predetermined belt load...

An active cannula or sleeve which does more than merely maintain a channel or passage is usable to create and/or enlarge a channel or passage, to position a scope or instrument, to move or locate tissue, etc. The cannula can vary in size or shape as needed, intraoperatively. Because a cannula of the present invention is expandable, the surgeon can make a small relatively small incision, stretch the tissue with the expandable cannula, contract the cannula and remove it, allowing the skin to come ...

A switching circuit has an active switch, a controller, and at least two terminals. The at least two terminals include two current control terminals for connection at two locations in another circuit. The controller is configured to turn the active switch off to block current between the two locations when the voltage between the two locations is of a first polarity and otherwise to turn the active switch on to conduct current between the two locations, whether or not the two current control ter...

Pseudo space transmitting signal processing means of the signal processing means simulates the frequency response of the space up to the silencing point from a noise source, while pseudo inverse filter signal processing means simulates an inverse filter characteristic 1/(K.times.Sp.times.G1) for canceling the characteristic of the combined frequency response (K.times.Sp.times.G1) of K of noise input means, Sp of a secondary sound source speaker, and G1 up to a silencing point from a secondary so...

A powder distribution device for transporting and mixing a fine powder with a gas is disclosed. The device presents a distribution member forming a connection between a source of fine powder and a discharge opening. The distribution member has a first inlet portion (10) and an outlet portion (12) for a stream of a first gas (1) mixed with the fine powder. The main body of the distribution member constitutes a porous body portion (16) being surrounded by a second gas (2). If a pressure gradient i...

Techniques for adjusting the voltage across an active filter element include a controlled circuit element and a control circuit element adapted to control the voltage across the controlled circuit element to increase transient load response and to reduce power dissipation.

An active inductor includes an MOSFET having a gate, a drain serving as an output terminal and a grounded source, the MOSFET having a transconductance gm1, and a capacitor having opposite ends, one of which is grounded and the other of which is connected to the gate of the MOSFET and to a voltage-controlled constant current source having a transconductance gm, the capacitor having a capacitance C, the active inductor being operative with a small-signal output impedance Zo between the output term...

The present invention relates to the art of personal mobility vehicles, particularly vehicles for the physically impaired. Particular application is found in children's wheelchairs which grow and expand with the child. However, it is to be appreciated that the present invention may also be applicable to wheelchairs for adults and may be utilized to custom fit wheelchairs to adults, may enable the chair to be utilized by adults or children of different sizes, or may be applicable to other vehicle...

An improved snubber is electrically switched to close a current path to a capacitor (C) in a series connected RC circuit at the onset of an abrupt voltage change otherwise producing ringing in a resonant circuit to which the snubber circuit is connected. The current path to the capacitor (C) is then interrupted before the capacitor (C) discharges and thereafter at each such voltage change in the resonant circuit the capacitor (C) is no longer charged from its totally discharged state but neverth...

An active armor system which includes an outer and an inner armor layer with a medial space between these inner and outer armor layers layer. One or more relatively small shaped charges are positioned on the inner armor layer in the medial space. If the outer armor layer is struck by a projectile having a shaped charge, one or more of the small shaped charges positioned in the medial space near where the projectile has struck the outer armor layer are detonated. The small shaped charges in the m...