Motion detector module

1. A motion detector comprising:

a housing having a front side and a back side;

a plurality of conductors disposed on said back side configured to electrically connect to a wiring module installed within an electrical box;

a first circuit board and a second circuit board retained within said housing, said second circuit board piggybacked on said first circuit board;

a lens disposed on said front side configured to focus IR radiation;

an IR sensor mounted within said housing configured to receive IR radiation from said lens and generate a sensor signal in response to motion across the field-of-view of said lens;

a controller responsive to said sensor signal so as to generate a switch signal;

a relay responsive to said switch signal so as to switch an electrical power source in communications with a power one of said conductors via said wiring module to an electrical power load in communication with a load one of said conductors via said wiring module; and

a relay driver configured to actuate said relay in response to said switch signal,

wherein said IR sensor and said controller are mounted on said first circuit board and said relay and said relay driver are mounted on said second circuit board.

2. The motion detector according to claim 1 further comprising:

a tap disposed on said second circuit board and in communication with said power conductor so as to provide said controller an AC signal,

said controller generating said switch signal on a zero crossing of said AC signal.

3. A motion detector comprising:

an electrical box configured to accept a plurality of electrical conductors in communications with a power source and a power load;

a wiring module having a wiring side and a functional side mounted within said electrical box;

a motion detector module having a front side and a back side removably mounted to said wiring module; and

a relay disposed within said motion detector module,

wherein said wiring module wiring side has terminations for said electrical conductors,

wherein said wiring module functional side has wiring module contacts electrically connected to said termination, said wiring module contacts comprising sockets having raised guards and recessed channels disposed around the peripheries thereof,

wherein said motion detector module front side has a lens for receiving IR radiation,

wherein said motion detector module back side has motion detector module contacts removably and electrically connected to said wiring module contacts, said motion detector module contacts comprising plugs having continuous walls disposed around the peripheries, and extending about the length, thereof, wherein said walls define open ends distal said back side and wherein said walls mate with said channels and said raised guards insert into said open ends as said plugs insert into said sockets,

wherein said motion detector module is responsive to motion within the field-of-view of said lens as to connect said power source with said power load via said motion detector module contacts,

wherein said relay has a switch moveable between a closed position connecting said power source to said power load and an open position disconnecting said power source from said power load, and

wherein said switch moves between said closed position and said open position only upon zero-crossings of said power source.

4. A motion detector method comprising the steps of:

routing conductors for an electrical power source and an electrical power load to an electrical box;

mounting a wiring module within said electrical box;

terminating said conductors at said wiring module;

physically mounting and electrically connecting a motion detector module to said wiring module so as to allow said motion detector module to communication with said electrical power source and said electrical power load via said wiring module;

receiving IR radiation into said motion detector module;

detecting motion from said IR radiation;

detecting a zero-crossing of said electrical power source corresponding to a change in AC voltage polarity; and

driving a relay in response to said detected motion and said detected zero-crossing so as to initiate switching said electrical power source to said electrical power load in response to motion in the field-of-view of said motion detector module.

5. The motion detection method according to claim 4 comprising the further step of:

interchangeably plugging said motion detector module and a switch module into said wiring module,

wherein said switch module is configured to manually connect and disconnect said electrical power source and said electrical power load.