Universal Lighting Technologies, Inc.

James Koehler

John Jay Dernovsek

Henry Jacobs

Giovanni Gallegos

Philip McKenzie

A control signal interface circuit includes a line voltage protection circuit coupled to first and second input terminals. The protection circuit provides an input DC voltage across the input terminals within a predetermined range (i.e., 0-10 Vdc) and prevents the application of an input line voltage (i.e., 347 Vac) across the input terminals. A first current source circuit is coupled to the protection circuit, an isolation circuit is coupled to the first current source circuit and a second current source circuit is coupled to the isolation circuit. The first and second current source circuits collectively provide a linear output DC voltage with respect to the input DC voltage. At least one of the first and second current source circuits include circuitry wherein the linear conversion of the input DC voltage to the output DC voltage is independent of the temperature.

Electronic ballast with protected analog dimming control interface

An asymmetric end-of-life protection circuit with single-point voltage measurement is provided for an electronic ballast having two lamp connection terminals. A grounding circuit includes a capacitor and a first resistor coupled in parallel between a first lamp connection terminal and ground, and is effective to drain the second lamp connection terminal to ground. A lamp voltage detection circuit is coupled between the first lamp connection terminal and ground and measures the lamp voltage from the first lamp connection terminal. A controller is effective to shut down the ballast based on an output signal from the lamp voltage detection circuit being greater than a first predetermined threshold value or less than a second predetermined threshold value.

Asymmetric end-of-life protection circuit for fluorescent lamp ballasts

A system and method is provided for encoding and decoding control signals to an electronic ballast. An encoding circuit is effective to transmit encoded control signals across an AC power line comprising patterns of energy bursts at zero crossings of an AC signal. Eight zero crossings define a set, five specific patterns of energy bursts within a set define distinct symbols, each defined symbol selected such that a Hamming distance between each symbol is greater than three. Four symbols correspond to a first logic condition and one symbol corresponds to a second logic condition. Each received symbol is sequentially associated with a distinct control channel having one or more control parameters. A receiving circuit in the ballast is effective to decode symbols with single-bit error correction by comparing received symbols to defined symbols and determining which symbol is a smallest Hamming distance from a received symbol.

System and method for encoding ballast control signals

A communication system and method is utilized to communicate data over an AC power line. Tone burst are superimposed on an AC power signal at predetermined voltage reference levels or at predetermined phase angles to represent bit values. These bit values are represented by either the presence or the absence of the tone burst on the AC power signal. In this manner, control information can be communicated to an apparatus, such as a ballast for a gas discharge lamp.

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Pflugerville, TX, United States of America

James Koehler