Patent ID: 7618585

Claim:
A fuel-concentration detecting and controlling device for a fuel cell, comprising: (a) a comparative fuel pool comprising a standard fuel pool and a fuel-mix pool separated by a barrier balancing temperature between said standard fuel pool and said fuel-mix pool; (b) an ultrasonic element comprising a first waveform-transforming device, a second waveform-transforming circuit and an intermittent-pulse-wave generator, an end of said first waveform-transforming circuit and an end of said second waveform-transforming circuit connecting respectively with an end of said standard fuel pool and an end of said fuel-mix pool; (c) a comparator, an end of said comparator connecting with another end of said first waveform-transforming circuit and another end of said second waveform-transforming circuit; (d) a server, an end of said server connecting with another end of said comparator; (e) a pure fuel pool; and (f) a controlling device, a control part of said controlling device connecting with another end of said server, two ways of said controlling device connecting with said pure fuel pool and said comparative fuel pool respectively, wherein a first transducer element is located at a place said first waveform-transforming circuit is connected with said standard fuel pool; wherein said first transducer element is a piezoelectric element; and wherein said piezoelectric element is a sensor, wherein a second transducer element is located at a place said second waveform-transforming circuit is connected with said fuel-mix pool; wherein said second transducer element is a piezoelectric element; and wherein said piezoelectric element is a sensor, wherein a third transducer element is located between said standard fuel pool and said fuel-mix pool and is connected with said intermittent-pulse-wave generator; wherein said third transducer element is a piezoelectric element; and wherein said piezoelectric element is a sensor.