System and method for power line carrier communication using high frequency tone bursts
AssigneeUniversal Lighting Technologies, Inc.
InventorsPhilip McKenzie, James Koehler
Life of this patent
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Abstract
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.
Claims24
A method of communicating data on an AC power line carrying an AC power signal comprising:
- (a) in accordance with the data to be communicated, periodically injecting a high frequency signal on the AC power line so that high frequency tone bursts are superimposed on the AC power signal;
- (b) detecting the presence and absence of the tone bursts on the AC power line signal;
- (e) decoding the detected presence and absence of the tone bursts to extract the data;
- wherein the data communicated across the power line is represented by a sequence of first and second bit values;
- and
- wherein the step of decoding the detected presence and absence of the tone bursts to extract the data further comprises
- determining if a tone burst is present on the AC power signal,
- generating an indicator signal if the tone burst is present on the AC power signal,
- transmitting the indicator signal to a pulse generation circuit that generates electrical pulses, and
- modifying the electrical pulses when the indicator signal is received by the pulse generation circuit so that a modified pulse corresponds to the first bit value and an unmodified pulse corresponds to the second bit value.
A system for communicating data on an AC power signal, comprising:
- an AC power line for transmitting the AC power signal;
- a tone generator circuit electrically coupled to the AC power line, the tone generator circuit generating high frequency tone bursts that are superimposed on the AC power signal in patterns corresponding to first and second bit values associated with the data to be communicated;
- a tone detection circuit comprising a pulse generation circuit that generates electrical pulses in response to an indicator signal;
- and
- the tone generation circuit is functional to
- detect the presence or absence of the tone bursts on the AC power signal,
- generate the indicator signal if the tone burst is present on the AC power signal,
- transmit the indicator signal to the pulse generation circuit, and
- modify the electrical pulses when the indicator signal is received by the pulse generation circuit so that a modified pulse corresponds to the first bit value and an unmodified pulse corresponds to the second bit value.
A method of determining data bit values being communicated on an AC power signal that is transmitted along an AC power line, the method comprising:
- (a) determining if a tone burst is present on the AC power signal;
- (b) generating an indicator signal if the tone burst is present on the AC power signal;
- (c) transmitting the indicator signal to a pulse generation circuit that generates pulses;
- and
- (d) modifying the pulses if the indicator signal is present whereby an unmodified pulse corresponds to a first bit value and a modified pulse corresponds to a second bit value.
A device for detecting tone bursts superimposed on an AC power signal, the tone bursts corresponding to lamp control signals being communicated across an AC power line to a ballast powering a gas discharge lamp, comprising:
- a filter circuit coupled to the AC power line to filter the tone bursts out of the AC power signal;
- a detector circuit connected to an output of the filter circuit, the detector circuit generating an indicator signal indicating the presence of the tone bursts on the AC power signal;
- and
- a pulse generating circuit that transmits pulses, the pulse generation circuit coupled to receive the indicator signal from the detector circuit and functional to modify a length of one of the pulses when the indicator signal indicates the presence of one of the tone bursts.
A method of communicating a data packet having data bits to an apparatus receiving power from an AC power signal on an AC power line, comprising:
- retrieving the data bits from the data packet for communication to the apparatus;
- generating a drive signal that activates a tone generator circuit connected to the AC power line, the drive signal activating the tone generator circuit to produce a tone burst on the AC power signal each time one of the data bits is of a first value and not activating the tone generator circuit each time one of the data bits is of a second value;
- receiving the AC power signal;
- determining the bit values of the data packet according to the presence or absence of tone bursts on the AC power signal.
Dependencies are inferred from the claim text.