# US 2014/0151558 A1 · Occupancy sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0151558 A1 - Document ID: US20140151558A1 - Status: Published application - Kind: A1 - Application number: 13/984,546 - Filed: 2011-03-11 - Published: 2014-06-05 - Earliest claimed: 2011-02-09 - Assignees: OSRAM GmbH - Inventors: Enrico Bortot; Christian Cecchetti; Stefan Hackenbuchner; Uwe Liess; Torsten Mannke - Web page: https://patentgrep.com/patent/US20140151558A1 ## CPC - H05B 47/115: by determining the presence or movement of objects or living beings - G01J 5/10: using electric radiation detectors - H05B 47/19: via wireless transmission - H05B 47/13: by using passive infrared detectors - Y02B 20/40: Control techniques providing energy savings, e.g. smart controller or presence detection - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - G01J: MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY (light sources F21, H01J, H01K, H05B; investigating properties of materials by optical means G01N) - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract An occupancy sensor with the following components is disclosed: a sensing probe to detect occupancy of a space monitored by the sensor and to produce a corresponding sensing signal; a comparator, including a voltage divider defining a comparison value, against which the sensing signal is compared to detect occupancy; and a voltage sensing means to sense a feed voltage applied to the sensor, where changes in the feed voltage to the sensor induce a change in the comparison value. ## Claims ### Claim 1 An occupancy sensor including: a sensing probe to detect occupancy of a space monitored by the sensor and produce a corresponding sensing signal, a comparator including a voltage divider defining a comparison value against which said sensing signal is compared to detect said occupancy, a voltage sensing means to sense a feed voltage applied to the sensor, wherein changes in said feed voltage induce a change in said comparison value, said voltage divider including at least one resistor selectively switchable to counter changes induced in said comparison value by changes in said feed voltage. ### Claim 2 (depends on 1) The sensor of claim 1, wherein said voltage divider defines a comparison window for said sensing signal with a width between an upper threshold and a lower threshold, wherein said voltage divider includes at least one resistor selectively switchable to counter changes in the width of said comparison window induced by changes in said feed voltage. ### Claim 3 (depends on 1) The sensor of claim 1, wherein said voltage divider includes a plurality of resistors wherein at least one resistor in said plurality is selectively switchable between two different resistance values. ### Claim 4 (depends on 3) The sensor of claim 3, wherein at least one resistor in said plurality is selectively switchable between a zero resistance value and a non-zero resistance value. ### Claim 5 (depends on 3) The sensor of claim 3, wherein said plurality of resistors includes a set of resistors switchable to resistance values arranged in an increasing series of powers of two. ### Claim 6 (depends on 3) The sensor of claim 3, wherein said at least one selectively switchable resistor is coupled to an associated electronic switch switchable to an active state to short-circuit the resistor coupled thereto. ### Claim 7 (depends on 6) The sensor of claim 6, wherein said electronic switch includes a MOSFET. ### Claim 8 (depends on 1) The sensor of claim 1, including a controller configured to selectively switch said at least one resistor in said voltage divider to counter changes induced in said comparison value by changes in said feed voltage. ### Claim 9 (depends on 8) The sensor of claim 8, wherein said controller is configured to selectively switch a plurality of switchable resistors in said voltage divider to cause the sum of the resistance values of the resistors activated by said switching to gradually increase as said feed voltage decreases. ### Claim 10 (depends on 8) The sensor of claim 8, wherein said controller comprises said voltage sensing means. ### Claim 11 (depends on 1) The sensor of claim 1, including a controller, configured to be selectively switched to an active state as comparison of said signal sensing signal against said comparison value in said comparator indicates occupancy being detected by said sensing probe. ### Claim 12 (depends on 11) The sensor of claim 11, wherein said controller is coupled to a radio transmitter to send a RF message when occupancy is detected by said sensing probe. ### Claim 13 (depends on 12) The sensor of claim 12, wherein said controller is configured to return to a sleep mode after sending said RF message. ### Claim 14 (depends on 13) The sensor of claim 13, wherein said controller is inhibited from switching to said active state for a given interval after returning to said sleep mode. ### Claim 15 (depends on 1) The sensor of claim 1, wherein said sensing probe is a Passive Infra Red or PIR sensing probe. ### Claim 16 (depends on 1) The sensor of claim 1, including conditioning circuitry for said sensing signal between said sensing probe and said comparator. ### Claim 17 (depends on 1) The sensor of claim 1, wherein the sensor is a battery-powered sensor whereby said feed voltage is battery voltage.