Abstract: Traditional flow sensors include an upstream resistive sensor element, a downstream resistive sensor element and an intervening heater resistive element. To help reduce the size and/or cost of such flow sensor, it is contemplated that the heater resistor may be eliminated. When so provided, the space required for the heater resistive element, as well as the corresponding heater control circuit, may be eliminated. This can reduce the cost, size and complexity of the flow sensor.

Abstract: A heater control circuit in a fluid flow sensor. The circuit comprises first, second, and third resistors, a heater resistor, a trimmable resistor, and a switch. A positive terminal of the first resistor is connected to a positive terminal of the trimmable resistor, a negative terminal of the first resistor is connected to a positive terminal of the heater resistor, a negative terminal of the trimmable resistor is connected to a positive terminal of the second resistor, a negative terminal of the second resistor is connected to a positive terminal of the third resistor, and a negative terminal of the heater resistor is connected to a negative terminal of the third resistor, the terminals of the second resistor are attached to the terminals of the switch, where the switch is configured closed in a calibration mode and configured open in a flow sensing mode.

Abstract: Traditional flow sensors include an upstream resistive sensor element, a downstream resistive sensor element and an intervening heater resistive element. To help reduce the size and/or cost of such flow sensor, it is contemplated that the heater resistor may be eliminated. When so provided, the space required for the heater resistive element, as well as the corresponding heater control circuit, may be eliminated. This can reduce the cost, size and complexity of the flow sensor. Coupling a resistive sensor element of such flow sensor to ground through a low temperature coefficient of resistance (TCR) resistor can reduce the variation of span of an output of the flow sensor which can improve resolution and accuracy of such sensor.

Abstract: A heater control circuit in a fluid flow sensor. The circuit comprises first, second, and third resistors, a heater resistor, a trimmable resistor, and a switch. A positive terminal of the first resistor is connected to a positive terminal of the trimmable resistor, a negative terminal of the first resistor is connected to a positive terminal of the heater resistor, a negative terminal of the trimmable resistor is connected to a positive terminal of the second resistor, a negative terminal of the second resistor is connected to a positive terminal of the third resistor, and a negative terminal of the heater resistor is connected to a negative terminal of the third resistor, the terminals of the second resistor are attached to the terminals of the switch, where the switch is configured closed in a calibration mode and configured open in a flow sensing mode.

Abstract: Traditional flow sensors include an upstream resistive sensor element, a downstream resistive sensor element and an intervening heater resistive element. To help reduce the size and/or cost of such flow sensor, it is contemplated that the heater resistor may be eliminated. When so provided, the space required for the heater resistive element, as well as the corresponding heater control circuit, may be eliminated. This can reduce the cost, size and complexity of the flow sensor. Coupling a resistive sensor element of such flow sensor to ground through a low temperature coefficient of resistance (TCR) resistor can reduce the variation of span of an output of the flow sensor which can improve resolution and accuracy of such sensor.

Abstract: Traditional flow sensors include an upstream resistive sensor element, a downstream resistive sensor element and an intervening heater resistive element. To help reduce the size and/or cost of such flow sensor, it is contemplated that the heater resistor may be eliminated. When so provided, the space required for the heater resistive element, as well as the corresponding heater control circuit, may be eliminated. This can reduce the cost, size and complexity of the flow sensor.

Abstract: A sensor housing includes an inlet flow port, an outlet flow port, a flow sensing region, and a flow channel extending between the inlet flow port, the flow sensing region and the outlet flow port. The flow channel defines a flow path between the inlet flow port and the flow sensing region that is contorted in three-dimensions. The three-dimensional contorted flow path between the inlet flow port and a flow sensing region may include a particle collection region that is configured to decelerate a fluid and collect particles that are released from the fluid. The deceleration of the fluid flow and/or one or more changes in the direction of fluid flow along the contorted three-dimensional flow path may cause dust and/or other particulate matter to be released from the fluid prior to reaching a sensor in the sensing region.

Abstract: The present disclosure relates to modular flow sensor assemblies and methods. The modular flow sensor assembly may include a main sensor body, a first end adapter having a first connection port configuration, and a second end adapter having a second connection port configuration. The main sensor body may include a main housing and a sensor, where the first end adapter is configured to engage the main housing and the second end adapter is configured to engage the main housing. The first end adapter and the second end adapter may be selected from a group of end adapters, wherein at least two of the end adapters has a different connection port configuration. The selected first end adapter and the selected second end adapters may have the same or different connection port configurations. The first end adapter and the second end adapter are configured to be interchangeable end adapters.

Abstract: A flow sensor assembly includes a flow sensor for sensing a flow parameter. The flow sensor may provide a flow sensor output signal that is related to the sensed parameter. A control block operatively connected to the flow sensor may receive a measure related to the flow rate of the fluid stream and drive the heater of the flow sensor to a heater temperature, such that the heater temperature may be dependent on the flow rate of the fluid stream, which causes the analog output of the flow sensor to be relatively linear over an expected operating range of flow rates.

Abstract: A sensor housing includes an inlet flow port, an outlet flow port, a flow sensing region, and a flow channel extending between the inlet flow port, the flow sensing region and the outlet flow port. The flow channel defines a flow path between the inlet flow port and the flow sensing region that is contorted in three-dimensions. The three-dimensional contorted flow path between the inlet flow port and a flow sensing region may include a particle collection region that is configured to decelerate a fluid and collect particles that are released from the fluid. The deceleration of the fluid flow and/or one or more changes in the direction of fluid flow along the contorted three-dimensional flow path may cause dust and/or other particulate matter to be released from the fluid prior to reaching a sensor in the sensing region.

Abstract: A sensor assembly includes a sense element for sensing a sensed parameter. The sense element may provide a sense element output signal that is related to the sensed parameter. A control block may include a first input port for receiving the sense element output signal, a second input port for receiving a scale input adjustable by a user, and an output port for providing a sensor assembly output signal. The control block may be configured to take in the sense element output signal via the first input port and produce the sensor assembly output signal at the output port, wherein the sensor assembly output signal at the output port is related to the sense element output signal and corresponds to a user selected range of the sensed parameter. The user selected range may be determined, at least in part, by the scale input received via the second input port.

Abstract: A flow sensor assembly that may include features that help prevent moisture from reaching a sensor die of the flow sensor assembly. In some cases, such features may include a bypass channel that is configured to reverse the direction of the flow of fluid at least once upstream of the sensor die. In some cases, an encapsulant may cover one or more bond pads of the sensor die. In some cases, an output of the flow sensor assembly may be a raw sensor output signal produced by the one or more sensor elements of the sensor die, without significant processing of the raw sensor signal.

Abstract: A flow sensor assembly includes a flow sensor for sensing a flow parameter. The flow sensor may provide a flow sensor output signal that is related to the sensed parameter. A control block operatively connected to the flow sensor may receive a measure related to the flow rate of the fluid stream and drive the heater of the flow sensor to a heater temperature, such that the heater temperature may be dependent on the flow rate of the fluid stream, which causes the analog output of the flow sensor to be relatively linear over an expected operating range of flow rates.

Abstract: A sensor assembly includes a sense element for sensing a sensed parameter. The sense element may provide a sense element output signal that is related to the sensed parameter. A control block may include a first input port for receiving the sense element output signal, a second input port for receiving a scale input adjustable by a user, and an output port for providing a sensor assembly output signal. The control block may be configured to take in the sense element output signal via the first input port and produce the sensor assembly output signal at the output port, wherein the sensor assembly output signal at the output port is related to the sense element output signal and corresponds to a user selected range of the sensed parameter. The user selected range may be determined, at least in part, by the scale input received via the second input port.

Abstract: The present disclosure relates to modular flow sensor assemblies and methods. The modular flow sensor assembly may include a main sensor body, a first end adapter having a first connection port configuration, and a second end adapter having a second connection port configuration. The main sensor body may include a main housing and a sensor, where the first end adapter is configured to engage the main housing and the second end adapter is configured to engage the main housing. The first end adapter and the second end adapter may be selected from a group of end adapters, wherein at least two of the end adapters has a different connection port configuration. The selected first end adapter and the selected second end adapters may have the same or different connection port configurations. The first end adapter and the second end adapter are configured to be interchangeable end adapters.