Apparatus and method for switch state detection and controlling electrical power

A method of detecting a position of a switch during a failure of a main power source, the method comprising:

• determining, by circuitry connected to the switch, when power from the main power source is absent;
• outputting, by the circuitry, based on the main power being absent, a test signal at a main power connection such that, when one or more devices are connected on a load side of the switch connecting the main power connection to the main power source, the one or more devices appear as a substantially open circuit to the test signal due to a rectifier included in each device of the one or more devices;
• and
• generating, by the circuitry, a switch state detection signal based on current flow generated as a result of the output of the test signal, wherein the generated switch state detection signal indicates the switch is closed when the current flow is greater than a predetermined threshold.

A device comprising:

• a main power connection configured to receive power from a main power source under normal conditions;
• a battery;
• a first lighting circuit including one or more lights, wherein the first lighting circuit is configured to be powered by the main power source when power from the main power source is available and to be powered from the battery when power from the main power source is absent and a switch that connects the main power source with the device is closed;
• and
• circuitry configured to
• determine, based on an input from the switch, when the power from the main power source is absent;
• output, based on the main power source being absent, a test signal at the main power connection such that, when a second lighting circuit is connected on a load side of the switch, the second lighting circuit appears as a substantially open circuit to the test signal due to a rectifier included in each light of one or more lights of the second lighting circuit;
• generate a switch state detection signal based on current flow generated as a result of the output of the test signal;
• and
• control power provided by the battery to the first lighting circuit including the one or more lights based on the switch state detection signal and the determination of whether power from the main power source is absent, wherein the circuitry is configured to generate the switch state detection signal to indicate the switch is closed when the current flow is above a predetermined threshold, and wherein the circuitry is configured to illuminate at least one of the one or more lights of the first lighting circuit when the power from the main power source is absent and the switch state detection signal indicates the switch is closed.