Pulse width modulated constant temperature anemometer

Details Pulse width modulated constant temperature anemometer Pulse width modulated constant temperature anemometer

1996-07-03

1997-08-05

Chilcot, Richard

Measuring and testing

Volume or rate of flow

Thermal type

G01F 168

Patent

active

056545070

ABSTRACT:
A constant temperature anemometer utilizes a fine wire or thin film sensor or probe and a pulse width modulated driver in a digital control loop to adjustably drive the probe to maintain its temperature at a nominally constant value and provide a digital output to associated metering or recording equipment. The pulse width modulated driver includes a clock, an RS flip-flop and a comparator. At the beginning of the clock cycle, power is provided to a voltage divider and the divided voltage drives one input of the comparator and the fine wire or thin film sensor. The other input of the comparator is maintained at a reference voltage. When the drive voltage to the hot wire or thin film sensor exceeds the reference voltage, the comparator provides a high logic signal to the RS flip-flop, resetting it and shutting off power to the sensor until the next clock cycle. The pulse width modulated drive signal may be utilized directly by an associated processor or computer. Various circuit features may be added to improve operation given specific installation or operating parameters.

REFERENCES:
patent: 3603147 (1971-09-01), Dorman
patent: 3905230 (1975-09-01), Calvet et al.
patent: 4043195 (1977-08-01), Hunting
patent: 4043196 (1977-08-01), Trageser
patent: 4059982 (1977-11-01), Bowman
patent: 4334186 (1982-06-01), Sasayama et al.
patent: 4335605 (1982-06-01), Boyd
patent: 4501145 (1985-02-01), Boegli et al.
patent: 4565091 (1986-01-01), Ito et al.
patent: 4596140 (1986-06-01), Dorman et al.
patent: 4655089 (1987-04-01), Kappelt et al.
patent: 4794794 (1989-01-01), Djorup
patent: 4807151 (1989-02-01), Citron
patent: 4852027 (1989-07-01), Bowman et al.
patent: 4934188 (1990-06-01), Tanimoto et al.
patent: 4934189 (1990-06-01), Tanimoto et al.
patent: 5064296 (1991-11-01), Huijsing et al.
patent: 5074147 (1991-12-01), Sarma
patent: 5117691 (1992-06-01), Fraser
patent: 5218866 (1993-06-01), Phillips et al.
patent: 5493906 (1996-02-01), Sem-Zhi

Affiliated with

Also associated with

Rating

Pulse width modulated constant temperature anemometer does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Pulse width modulated constant temperature anemometer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pulse width modulated constant temperature anemometer will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1076496