A flow sensor includes sensors connected to a flexible membrane. The sensors
detect
ambient temperature, pressure, and flow rate of a medium. A method of sensing flow
rate includes providing the flexible membrane; coupling the plurality of sensors
to the flexible membrane; and detecting ambient temperature, pressure, and flow
rate of the medium by the sensors. A flow sensing system includes the flow sensor,
an operational amplifier, and a closed loop controller. The sensors are connected
in a Wheatstone bridge configuration. The operational amplifier is connected to
the Wheatstone bridge and outputs a pressure signal representative of the pressure
of the medium. The closed loop controller is connected to the operational amplifier
and controls a current through a heating element for a resistor in the bridge such
that a voltage across the operational amplifier is substantially zero. The output
of the closed loop controller represents the flow rate.
