Invention Grant
- Patent Title: Smoke detector with regulated constant-current circuit for driving optical sources
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Application No.: US14717739Application Date: 2015-05-20
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Publication No.: US09622301B2Publication Date: 2017-04-11
- Inventor: Daniel Adam Warren , Ian C. Smith , Brian Jonathan Conner
- Applicant: Google Inc.
- Applicant Address: US CA Mountain View
- Assignee: GOOGLE INC.
- Current Assignee: GOOGLE INC.
- Current Assignee Address: US CA Mountain View
- Agency: Van Court & Aldridge LLP
- Main IPC: G08B17/10
- IPC: G08B17/10 ; H05B33/08 ; G01N21/53 ; G08B17/107

Abstract:
Systems and methods for driving optical sources operating at different wavelengths within a smoke sensor are described herein. Multiple optical sources such as light emitting diodes may be used in a photoelectric smoke sensor to detect particles of different sizes. Photoelectric smoke sensors can operate by pulsing the LEDs and measuring a response in a light sensor. The signal measured at the light sensor changes based on the quantity of particles existing in a smoke chamber. Each optical source may have different operational characteristics and thus require different drive currents to operate. LED driving circuitry according to embodiments discussed herein provide a consistent and reliable drive current to each optical source, while maximizing efficiency of power consumption across a range of possible voltages provided by different power sources.
Public/Granted literature
- US20160345394A1 SMOKE DETECTOR WITH REGULATED CONSTANT-CURRENT CIRCUIT FOR DRIVING OPTICAL SOURCES Public/Granted day:2016-11-24
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