A pressure switch for controlling application of negative pressure to dressing disposed adjacent a tissue site is disclosed. The pressure switch comprises a body having a base, sidewalls extending from the base to an open end, and an inlet coupled to the dressing and forming a passage through the body. The pressure switch further comprises a diaphragm closing the open end of the sidewalls and forming a vacuum chamber with the body, wherein the inlet fluidly couples the vacuum chamber and the dressing. The pressure switch further comprises a valve disposed in the passage and configured to restrict the flow of gas through the passage so that a switch pressure developed in the vacuum chamber as a result of the application of negative pressure to the dressing lags a wound pressure at the tissue site to delay, wherein the diaphragm is adapted to be operatively responsive to the switch pressure to move between a relaxed position and a compressed position as the negative pressure increases and decreases. This pressure switch further comprises a switching element coupled to the diaphragm to turn on the negative pressure in the relaxed position and turn off the negative pressure in the compressed position. In another example, a method for controlling application of negative pressure to dressing disposed adjacent a tissue site using a pressure switch is disclosed. In another example, a system for applying negative pressure to a tissue site using a pressure switch is disclosed.

The present disclosure provides a contact signal acquisition circuit for online checking a gas density relay on site. The contact signal acquisition circuit for online checking a gas density relay on site includes a first connecting circuit and a second connecting circuit, the first connecting circuit connecting a contact of a gas density relay to a contact signal control loop, and the second connecting circuit connecting a contact of the gas density relay to a contact signal sampling interface of an online check device, where in a non-checking state, the second connecting circuit is disconnected, and the first connecting circuit is closed; and in a checking state, the first connecting circuit is disconnected, and the second connecting circuit is connected, so as to connect the contact of the gas density relay to the contact signal sampling interface of the online check device, guarantee that a contact action signal is not uploaded during checking and safe operation of a power grid is not affected, omit maintenance of the gas density relay, greatly improve benefits and improve reliable and safe operation of the power grid.

Examples are disclosed that relate to magnetically aligned switching circuits. One disclosed example provides an electronic component comprising a first terminal, a second terminal, and a deformable host material arranged between the first terminal and the second terminal. Aligned magnetically within the host material is an ensemble of particles each comprising a ferromagnetic material, each particle having greater electrical conductivity than the host material. The ensemble of particles is configured to form at least one complete conduction path from the first terminal to the second terminal.

A method for determining an airflow volume through an air filter is presented. A negative pressure is created within a system housing of an air handling system. Particulate matter is filtered on a filter media of an air filter. A displaceable baffle is progressively moved baffle in proportion to an accumulation of particulate matter on the filter media, wherein the displaceable baffle is movably mounted within a bypass conduit of an airflow sensor device. An output voltage is identified from a magnetic field sensor, wherein the output voltage is proportional to a magnetic flux density of a magnetic field from an actuation magnet mounted on the displaceable baffle. A position of the displaceable baffle is determined based on the output voltage generated by the magnetic field sensor. An accumulation of particulate matter on the filter media is determined based on the position of the displaceable baffle.

An orifice module for a flow switch system has a cylindrical body which is symmetric about a central axis which defines a metering orifice. An axial central hub holds the stem. The hub connects to the cylindrical body by at least three support spokes which forms a plurality of flow channels angularly disposed about the central axis. The module interacts with the flow switch to enhance the function of the flow switch and also reduces turbulence in the fluid flow system.

A pressure sensor apparatus and a method of operating the pressure sensor apparatus can include a hybrid pressure switch having a single switching point, the hybrid pressure switch comprising: a mechanical pressure switch; and an electronic pressure sensor, wherein the hybrid pressure switch monitors a media pressure with the mechanical pressure switch providing a switching function and the electronic pressure sensor providing a continuous pressure measurement with respect to the media pressure based on a continuous pressure output signal. The switching function can comprise a fail-safe switching function or a non-fail-safe switching function.

Provided are a battery pack, and a transportation apparatus including the battery pack. The battery pack includes a battery module, a battery management system configured to control charging and discharging operations of the battery module, a power supply terminal arranged to supply operation power, and a switch connected between the power supply terminal and the battery management system, and configured to be turned on in response to an abnormal situation of the battery module. Accordingly, it is possible to provide a battery pack, and a transportation apparatus including the battery pack, which may start a suitable protection operation by waking up a battery management system for monitoring a state of the battery pack, and by controlling a charge/discharge operation thereof, by detecting an abnormal situation of a battery module even when the battery management system is in a sleep mode.

Disclosed is an intermittent pressure switch for pneumatic valves to control pressure relief valves in oil and gas producing operations by directing the valve to open and close based on pressure parameters (pre)set by the user. This enables oil and gas wells to produce based on formation pressure buildup. The inventive switch consists of a box containing a pressure switch programmable from 0 to 5,000 psi, a 3-port solenoid valve, 24 volt battery system, solar panel, solar control charger, pressure gauge, circuit wiring, and pressure fittings.

An electrical system is provided. In a non-limiting embodiment, an electrical system may include a load circuit comprising a plurality of series-connected storage/converter cells for supplying the load circuit, and an event sensor. Isolator switches may be provided between series-connected storage/converter cells, said isolator switches being in a closed position during normal operation of the electrical system, and being arranged such that they change to an open position when the event sensor is triggered.

A control module for use with a plurality of wellbore tools may include a power source and a logic circuit operably coupled to the power source. The logic circuit may be operably coupled to the plurality of wellbore tools through a topmost wellbore tool of the plurality of wellbore tools. The logic circuit may be configured to, in response to an initiation condition and for each wellbore tool of the plurality of wellbore tools in a sequential order from a bottommost wellbore tool to the topmost wellbore tool, determine whether the wellbore tool is a responsive wellbore tool or a non-responsive wellbore tool. In response to a determination that the wellbore tool is a responsive wellbore tool, the logic circuit may initiate the wellbore tool. In response to a determination that the wellbore tool is a non-responsive wellbore tool, the logic circuit may skip initiation of the wellbore tool.