Flow pickup circuit

A method of receiving a flow signal from a flow sensor and providing a flow indicator signal corresponding to flow characteristics through the flow sensor, comprising:

• producing a first sensing signal via an inner bridge circuit, constructed and arranged so as to operate in a constant current mode, wherein one or more of the components of the inner bridge is the flow sensor;
• producing a second sensing circuit via an outer bridge circuit, constructed and arranged so as to operate in a constant temperature mode, wherein the inner bridge circuit is one of the components of the outer bridge circuit;
• and,
• receiving the first sensing signal and the second sensing signal and producing the flow indicator signal therefrom.

A flow pickup circuit for receiving a flow signal from a flow sensor and providing a flow indicator signal corresponding to flow characteristics through the flow sensor, comprising:

• an inner bridge circuit constructed and arranged so as to operate in a constant current mode, and to produce a first sensing signal, the inner bridge circuit including four components connected in a series loop characterized by a first pair of diagonally-situated nodes and a second pair of diagonally-situated nodes, and the first sensing signal includes a voltage potential between the first pair of diagonally-situated nodes, wherein two of the four components include the flow sensor, disposed between the second pair of diagonally-situated nodes;
• an outer bridge circuit, constructed and arranged so as to operate in a constant temperature mode, and to produce a second sensing signal, the outer bridge circuit including four components connected in a series loop characterized by a first pair of diagonally-situated nodes and a second pair of diagonally-situated nodes, the second sensing signal including a voltage potential between the first pair of diagonally-situated nodes, wherein one of the four components includes the inner bridge circuit;
• a processor for receiving the first sensing signal and the second sensing signal and producing the flow indicator signal therefrom, wherein the processor subtracts an ambient temperature component from the second sensing signal, so as to produce a constant temperature flow indicator.