Abstract: A pole attachment mechanism for removably attaching swimming pool maintenance accessories to an end of a pole. The pole attachment mechanism includes a thumb-press which, when pressed, the pegs projecting from the shaft of the pole attachment are retracted thereby permitting the pole to be received over the retracted pegs or to be released from pegs.

Abstract: A feedback control loop around a gain element controls the output signal of said gain element responsive to an input or reference signal, and is additionally responsive to a non-linear feedback signal. The feedback loop of this invention comprises computation means for exponentiating a signal representing the output of the gain element to generate said non-linear feedback signal. The control loop of invention provides exceptional transient response when used for driving reactive loads.

Abstract: A power-conversion regulator comprising an inductive reactor, an output filter reactor, and a switch for admitting energy to the inductive reactor, additionally comprises computation circuitry responsive to the flux in the inductive reactor, to a reference signal, to an output voltage, and sometimes to an output load current, for computing the quantity of energy that must be supplied to a load and to the output filter reactor to regulate the output voltage or current to a desired relationship with the reference signal during each chopping waveform cycle driving the switch. As the inductive reactor is charged from an input energy source, the computation circuitry predicts whether the energy in the inductive reactor has become adequate for the regulation.

Abstract: An accelerometer senses equine respiratory structural vibrations. The accelerometer includes a sensing surface configured to be attached to one of hair, skin, bone, ligament, cartilage, and other tissue of a horse. The accelerometer is responsive to respiratory structural vibrations of the horse and outputs a signal corresponding to the respiratory structural vibrations.