Patent ID: 8159139

Claim:
A control element for a luminaire, the control element arranged to be connected to the luminaire unit over a pair of wires carrying an alternating current power signal, the control comprising: a first manually variable non-momentary impedance; a second manually variable non-momentary impedance; a first time dependent gating circuit, responsive to said first manually variable non-momentary impedance, arranged to provide a time dependent gating of a first polarity of the alternating current power signal, the amount of time of said gating of said first polarity reflecting the present value of said first manually variable non-momentary impedance; and a second time dependent gating circuit, responsive to said second manually variable non-momentary impedance, arranged to provide a time dependent gating of a second polarity of the alternating current power signal, said second polarity opposite said first polarity, the amount of time of said gating of said second polarity reflecting the present value of said second manually variable non-momentary impedance, wherein said first time dependent gating circuit and said second time dependent gating circuit are restrained to maintain a minimum predetermined power towards the luminaire.