Abstract: This device is an aid for a downhill skier regain his upright stance after a fall. A socket or loop of fabric is attached at the tail of the skis such that the tips of the poles can be thrust through the loop and into the underlying snow. When the skier then pulls himself up by pushing down and back on the poles, the skis are held in place and the skier easily regains his upright stance.

Abstract: An electronic ballast-inverter for multiple fluorescent lamps employs a push-pull inverter and a series resonant circuit for driving the lamps. The inverter operates at the resonant frequency of the series resonant circuit. The current in the resonant circuit is limited, for low load conditions, in response to a sensing voltage which is used to raise the frequency of operation of the inverter to make the load more reactive.

Abstract: An electronic ballast-inverter for multiple fluorescent lamps employs a push-pull inverter and a series resonant circuit for driving the lamps. The inverter operates at the resonant frequency of the series resonant circuit. Current in the resonant circuit is limited, for low-load conditions, in response to a sensing voltage which is used to lower the frequency of operation of the inverter, to make the load more reactive.

Abstract: A touch dimmer switch incorporating an integrated circuit for controlling a thyristor dimming circuit, has a touch control connected in a high impedance, unidirectionally conducting circuit, and a filter circuit for filtering out ambient electrical noise. The touch control is isolated from the AC power source so that the polarity of connection to the power source is not critical.

Abstract: A pulse width modulated switching amplifier is provided for amplifying an analog signal. Means is provided for producing positive and negative signals representative of positive and negative excursions of the analog signal, respectively. The positive and negative signals are applied to level shifters which produce positive and negative replica signals having the same waveshapes as the positive and negative signals, respectively, but which vary about a predetermined reference level. The level shifted replica signals are then applied to first and second comparators, respectively, which continuously sum the instantaneous magnitude thereof with the instantaneous magnitude of a triangular modulation signal also varying about the reference level. Each comparator produces a logical ONE output signal when the sum is positive and a logical ZERO output signal when the sum is negative.