Self-powered long-life occupancy sensors and sensor circuits
View Patent ↗Occupancy sensors are provided that do not require an external power source in order to operate. The sensors operate with a low voltage non-rechargeable battery and are fully functional for at least about 15-20 years. The sensors include a relay output capable of switching high or low voltage and high or low current with virtually no generated heat. The sensors require no warm-up period, no minimum load, and no external ground connection. The sensors are always active and are easily installed, having two electrically interchangeable outputs for coupling to, for example, a load and a load power source.
1. A method of coupling a first relay output to a second relay output based on occupancy sensed within a designated area, said method comprising:
sensing occupancy within said designated area;
generating a signal indicating occupancy in response to said sensing; and
coupling said first and second relay outputs to each other using an armature operative to couple AC line voltage with no more than about 3 volts supplied to a latching relay circuit that generates a single electrical pulse in response to the generated signal, the 3 volts provided exclusively by a non-rechargeable battery.
2. The method of claim 1 wherein said coupling comprises coupling said first and second relay outputs to each other using a relay coil powered by no more than about 3 volts supplied by a non-rechargeable battery in response to said generated signal.
3. The method of claim 1 wherein said non-rechargeable battery supplies no more than about 3-6 volts.
4. The method of claim 1 wherein said first relay output is operative to be coupled to a load and said second relay output is operative to be coupled to power for said load.
5. The method of claim 1 wherein said generating comprises amplifying a signal indicating occupancy using no more than about 30 microamperes of current supplied by said non-rechargeable battery in response to said sensing.
6. The method of claim 1 further comprising:
activating a timer for a limited period of time in response to said generated signal;
decoupling said first and second outputs from each other in response to said limited period of time expiring; and
powering said generating, said activating, and said decoupling with said non-rechargeable battery.
7. The method of claim 1 further comprising:
illuminating a light emitting diode in response to said generated signal; and
powering said sensing, said generating, and said illuminating with said non-rechargeable battery.
8. The method of claim 1 further comprising enclosing said non-rechargeable battery, said sensing, said generating, and said coupling in a single housing.
9. A method of coupling a first relay output to a second relay output based on occupancy sensed within a designated area, said method comprising:
sensing occupancy within said designated area;
generating a signal to a timer, wherein the signal indicates occupancy in response to said sensing;
activating the timer for a limited period of time in response to said generating a signal;
applying a voltage pulse of a first polarity across a relay coil in response to said activating;
coupling said first and second relay outputs to each other with no more than about 3 volts supplied by a non-rechargeable battery in response to said generated signal;
applying a second voltage pulse of a second polarity across said relay coil in response to said limited period of time expiring;
decoupling said first and second relay outputs from each other in response to said applying a second voltage pulse; and
powering said timer and said relay coil with said non-rechargeable battery.
10. Apparatus for coupling a first relay output to a second relay output based on occupancy sensed within a designated area, said apparatus comprising:
means for sensing occupancy within said designated area;
means for generating a signal indicating occupancy in response to sensing occupancy; and
means for coupling said first and second relay outputs to each other using an armature operative to couple AC line voltage with no more than about 3 volts supplied to a latching relay circuit that generates a single electrical pulse in response to the generated signal, the 3 volts provided exclusively by a non-rechargeable battery.
11. The apparatus of claim 10 further comprising:
means for coupling said first relay output to a load; and
means for coupling said second relay output to power for said load.
12. The apparatus of claim 10 wherein said means for generating comprises means for amplifying a signal indicating occupancy using no more than about 30 microamperes of current supplied by said non-rechargeable battery in response to said sensing.
13. The apparatus of claim 10 further comprising means for illuminating a light emitting diode in response to generating a signal.
14. The apparatus of claim 10 further comprising means for enclosing said non-rechargeable battery, said means for sensing, said means for generating, and said means for coupling.
15. The apparatus of claim 14 wherein said means for enclosing comprises a single housing.
16. The apparatus of claim 10 wherein said means for coupling comprises a relay coil.
17. The method of claim 9 further comprising:
coupling said first relay output to a load; and
coupling said second relay output to power for said load.
18. The method of claim 9 wherein said generating comprises amplifying a signal indicating occupancy using no more than about 30 microamperes of current supplied by said non-rechargeable battery in response to said sensing.
19. The method of claim 9 further comprising illuminating a light emitting diode in response to said generated signal.
20. The method of claim 9 further comprising enclosing said non-rechargeable battery, said sensing, said generating, and said coupling in a single housing.