US 12,217,585 B1
Aspirated smoke fire detector, fire protection system, airflow detection circuit and method
Xuemei Jiang, Beijing (CN); and Yajie Wang, Beijing (CN)
Assigned to BEIJING JADE BIRD UNIVERSAL FIRE PROTECTION SYSTEM SOFTWARE SERVICE CO., LTD., Beijing (CN); and JADE BIRD FIRE CO., LTD., Beijing (CN)
Filed by BEIJING JADE BIRD UNIVERSAL FIRE PROTECTION SYSTEM SOFTWARE SERVICE CO., LTD., Beijing (CN); and Jade Bird Fire Co., Ltd., Beijing (CN)
Filed on Aug. 29, 2024, as Appl. No. 18/818,994.
Claims priority of application No. 202410702822.8 (CN), filed on May 31, 2024.
Int. Cl. G08B 17/10 (2006.01); G08B 17/06 (2006.01)
CPC G08B 17/06 (2013.01) [G08B 17/10 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An airflow detection circuit, comprising:
a first thermistor, wherein one terminal of the first thermistor is coupled to a first resistor and a first switch, and the other terminal of the first thermistor is coupled to a first input terminal of a first operational amplifier;
a second thermistor, wherein one terminal of the second thermistor is coupled to the first resistor and the first switch, and the other terminal of the second thermistor is coupled to a second input terminal of the first operational amplifier;
a voltage source, coupled to the first resistor and the first switch and configured to provide a supply voltage for the first thermistor and the second thermistor through a corresponding supply path based on ON or OFF of the first switch; and
a controller, coupled to an output terminal of the first operational amplifier and configured to collect an output signal of the first operational amplifier and determine an airflow flow rate based on the output signal.