Measuring and testing – Volume or rate of flow – Thermal type
Patent
1997-08-28
1998-10-27
Noori, Max H.
Measuring and testing
Volume or rate of flow
Thermal type
7320417, G01F 168
Patent
active
058279601
ABSTRACT:
A low cost, bi-directional manifold air flow sensing device based on sensed temperature differential due to airflow achieves improved sensitivity and frequency response by eliminating the heater element of the conventional sensor topology, and operating the sensor elements at a relatively higher current so that each temperature sensing element heats both itself and the other temperature sensing element. The sensitivity is significantly increased due to the increased current in the sensor elements, and the frequency response is significantly increased due to closer spacing of the sensor elements. With this new topology, the sensor elements are said to be mutually heated. In a particularly advantageous mechanization, the sensing device includes two separate pairs of upstream and downstream sensing elements, and the sensing elements are connected in the four legs of a Wheatstone bridge. The sensitivity is doubled since sensor elements are connected in each of the bridge legs, and performance and cost are improved through the elimination of off-chip bridge components. A simple, low cost, temperature compensation circuit compensates for ambient temperature variations.
REFERENCES:
patent: 4279147 (1981-07-01), Djorup
patent: 4576050 (1986-03-01), Lambert
patent: 4677850 (1987-07-01), Miura et al.
patent: 4782708 (1988-11-01), Harrington et al.
patent: 4966037 (1990-10-01), Summer et al.
patent: 5243858 (1993-09-01), Erskine et al.
patent: 5263380 (1993-11-01), Sultan
patent: 5515714 (1996-05-01), Sultan et al.
patent: 5520047 (1996-05-01), Takahashi et al.
patent: 5569851 (1996-10-01), Ichimaru et al.
patent: 5629481 (1997-05-01), Sultan
Catalan Antonio Buddy
Harrington Charles Robert
O'Rourke Michael James
Sultan Michel Farid
General Motors Corporation
Noori Max H.
Simon Anthony Luke
LandOfFree
Bi-directional mass air flow sensor having mutually-heated senso does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Bi-directional mass air flow sensor having mutually-heated senso, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bi-directional mass air flow sensor having mutually-heated senso will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1614617