Other

Beatrice Foods Co.

General Electric Company

Thomas P Kohler

A ladder leveler is disclosed in which two pivoting arms are mounted on a base plate to provide a self-adjusting and infinitely adjustable device. The two arms cooperate with a movable locking member or tumbler which is mounted between the arms and shaped to permit the arms to self adjust for uneven ground and lock the arms against movement when weight is placed on the ladder. The device may be readily secured to and removed from the base of a ladder without extensive disassembly.

Ladder leveler

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.

Electronic fluorescent lamp ballast

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.

Electronic ballast-inverter for multiple fluorescent lamps

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.

Touch dimmer circuit

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. A switching circuit receives the logical signals from the comparators and produces an output pulse of one polarity when both comparators are producing logical ONE signals, an output pulse of the opposite polarity when both comparators are producing logical ZERO signals, and no output when the comparators are producing unlike logical signals. The output pulses are applied to a demodulator which produces an amplified replica of the analog signal.

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Baldwinsville, NY, United States of America

Thomas P Kohler