Stray voltage detection

1. A processor-based device comprising:

a chassis having a chassis ground node arranged to electrically couple the chassis to an earth ground;

a first connector accessible from an exterior of the chassis, the first connector including a set of first connector elements arranged to interface with a corresponding set of second connector elements of a second connector, wherein the first and second connector elements include a plurality of electrical signal conduits, wherein the first and second connectors conform to a powerline interface, and wherein the powerline interface includes at least a hot power signal, a load power signal, and a neutral power signal;

a processor-based apparatus housed at least in part within the chassis, the processor-based apparatus arranged to operate using direct current (DC) power derived from alternating current (AC) power present at the powerline interface; and

a stray voltage detector to detect, when the powerline interface is energized, a stray voltage potential between the neutral power signal of the powerline interface and the chassis ground node, wherein the processor-based device is further arranged to communicate at least one indication of the detected stray voltage potential.

2. The processor-based device of claim 1 , wherein the powerline interface conforms to a standard provided by the National Electrical Manufacturers Association (NEMA).

3. The processor-based device of claim 1 , wherein the second connector is integrated in a luminaire.

4. The processor-based device of claim 1 , wherein the stray voltage detector comprises:

a stray voltage isolation circuit; and

a stray voltage measurement/processing circuit arranged to receive an output signal from the stray voltage isolation circuit and further arranged to assert an output when the output signal from the stray voltage isolation circuit crosses a threshold.

5. The processor-based device of claim 4 , wherein the stray voltage isolation circuit comprises:

an operational amplifier having an inverting input node, a non-inverting input node, and an output node, the operational amplifier configured to amplify a difference in voltage between the inverting input node and the non-inverting input node.

6. The processor-based device of claim 5 , wherein the inverting input node of the operational amplifier is electrically coupled to the chassis ground node and wherein the non-inverting input node of the operational amplifier is electrically coupled to the neutral power signal.

7. The processor-based device of claim 4 , wherein the stray voltage isolation circuit comprises:

a ground reference protection circuit arranged to electrically separate a digital circuit ground plane of the stray voltage detector from the chassis ground node.

8. The processor-based device of claim 4 , wherein the stray voltage isolation circuit comprises:

at least one Zener diode electrically coupled to the output node of the operational amplifier.

9. The processor-based device of claim 4 , wherein the stray voltage measurement/processing circuit is arranged to set a stray voltage threshold, determine when the stray voltage potential has crossed the stray voltage threshold, and communicate an alert based on the determination.

10. The processor-based device of claim 9 , wherein the alert includes at least one of an audio alert, a visual alert, and a short-range wireless alert.

11. The processor-based device of claim 9 , wherein the alert includes at least one packetized message communicated toward a remote computing device via a cellular-based communication medium.

12. An apparatus arranged for attachment to a luminaire of a streetlight, the luminaire having one or more light emitting elements and a receptacle that conforms to a powerline interface, the apparatus comprising:

a housing connected to a chassis ground;

a connector accessible from an exterior of the housing, the connector including a set of connector elements that interface with corresponding receptacle elements of the receptacle of the luminaire;

one or more processor-based devices housed at least in part within the housing, the one or more processor-based devices being operable by receiving direct current power relative to a digitally stable ground; and

circuitry within the housing for detecting a stray voltage between the chassis ground and a neutral power line signal passed through the connector.

13. The apparatus of claim 12 , wherein at least one of the one or more processor-based devices is a wireless communications transceiver for sending and receiving wireless communication signals.

14. The apparatus of claim 12 , wherein at least one of the one or more processor-based devices is a camera.

15. The apparatus of claim 12 , further comprising:

one or more sensors communicatively coupled to the one or more processor-based devices.

16. The apparatus of claim 12 , further comprising:

a switching element; and

a photosensor arranged to provide an output that selectively causes the switching element to transition between a first state and a second state.

17. The apparatus of claim 12 , wherein the connector is compliant with American National Standards Institute (ANSI) C136.

18. A method comprising:

receiving, by a processor-based device, a hot power signal, a load power signal, and a neutral power signal passed via a connector;

producing a stray voltage signal with an operational amplifier by differentially amplifying at least a portion of the neutral power signal applied at a first input of the operational amplifier and at least a portion of an earth/chassis ground potential applied at a second input of the operational amplifier;

detecting when the stray voltage signal or a representation of the stray voltage signal crosses a threshold; and

asserting, by the processor-based device, an output based on the detecting.

19. The method of claim 18 , comprising:

coupling the processor-based device to a receptacle of a luminaire.

20. The method of claim 18 , wherein asserting an output comprises at least one of:

directing a light source to illuminate;

directing an audio source to produce an alert sound; and

communicating at least one packetized message toward a remote computing device via a cellular-based communication medium.