Power Measurement In A Two-Wire Load Control Device

A two-wire load control device comprising:

• a communication circuit;
• a controllably conductive device configured to be coupled in series electrical connection between an alternating current (AC) power source and a lighting load;
• and
• a control circuit configured to:
• render the controllably conductive device non-conductive during a first portion of a half-cycle of an AC waveform generated by the AC power source and to render the controllably conductive device conductive during a second portion of the half-cycle of the AC waveform;
• compute a voltage across the lighting load during the second portion of the half-cycle based on a voltage across the two-wire load control device during the first portion of the half-cycle;
• measure a current supplied to the lighting load during the second portion of the half-cycle;
• compute an estimated amount of power consumed by the lighting load based on the computed voltage and the measured current;
• and
• communicate via the communication circuit the estimated amount of power consumed by the lighting load.

A method performed by a control circuit of a two-wire load control device configured to control power delivered to a lighting load, the method comprising:

• rendering a controllably conductive device non-conductive during a first portion of a half-cycle of an alternating current (AC) waveform generated by an AC power source;
• rendering the controllably conductive device conductive during a second portion of the half-cycle of the AC waveform;
• computing a voltage across the lighting load during the second portion of the half-cycle based on a voltage across the two-wire load control device during the first portion of the half-cycle;
• measuring a current supplied to the lighting load during the second portion of the half-cycle;
• computing an estimated amount of power consumed by the lighting load based on the computed voltage and the measured current;
• and
• communicating via a communication circuit the estimated amount of power consumed by the lighting load.