A pressure switch includes an actuation unit disposed within a body of the pressure switch and biased in a first direction by a spring arrangement and accessible at a fitting end of the pressure switch to be movable in a second direction against the bias of the spring by fluid at the fitting end. The actuation unit includes a limiter trapped in a pocket to limit the range of travel of the actuation unit, thereby safeguarding the electrical switch element from sustaining damage due to excessive travel. The pocket may be formed by the cooperation of two separate pieces. The spring arrangement may be biased by another piece disposed within a body of the pressure switch.

A pressure switch includes an actuation unit disposed within a body of the pressure switch and biased in a first direction by a spring arrangement and accessible at a fitting end of the pressure switch to be movable in a second direction against the bias of the spring by fluid at the fitting end. The actuation unit includes a limiter trapped in a pocket to limit the range of travel of the actuation unit, thereby safeguarding the electrical switch element from sustaining damage due to excessive travel. The pocket may be formed by the cooperation of two separate pieces. The spring arrangement may be biased by another piece disposed within a body of the pressure switch.

Disclosed are a gas density relay having a simulation check function and a simulation check method thereof, the gas density relay includes a gas density relay body, a simulation reference signal unit, a simulation check signal unit, a driving contact action mechanism, and an intelligent control unit. The intelligent control unit obtains, according to the check, by the simulation reference signal unit, of a simulation check signal generated by the simulation check signal unit, a current working state of a monitoring part, so as to quantitatively and accurately measure the precision of the gas density relay; by providing the driving contact action mechanism, the gas density relay body generates an alarm and/or a locking contact action to ensure that a contact execution mechanism of the gas density relay body and a contact itself are normal. The present application completes online simulation or virtual check of the gas density relay while being used for monitoring the gas density of a insulation or arc extinguishing electrical equipment, thereby improving working efficiency, reducing operation and maintenance costs, and guaranteeing safe operation of a power grid.

Disclosed are a gas density relay having a simulation check function and a simulation check method thereof, the gas density relay includes a gas density relay body, a simulation reference signal unit, a simulation check signal unit, a driving contact action mechanism, and an intelligent control unit. The intelligent control unit obtains, according to the check, by the simulation reference signal unit, of a simulation check signal generated by the simulation check signal unit, a current working state of a monitoring part, so as to quantitatively and accurately measure the precision of the gas density relay; by providing the driving contact action mechanism, the gas density relay body generates an alarm and/or a locking contact action to ensure that a contact execution mechanism of the gas density relay body and a contact itself are normal. The present application completes online simulation or virtual check of the gas density relay while being used for monitoring the gas density of a insulation or arc extinguishing electrical equipment, thereby improving working efficiency, reducing operation and maintenance costs, and guaranteeing safe operation of a power grid.

The application provides a gas density relay with online self-check function and its check method, including a gas density relay body, a first pressure sensor, a second pressure sensor, a temperature sensor, a gas chamber, a pressure regulating mechanism, an online check contact signal sampling unit and an intelligent control unit. The air path of the pressure regulating mechanism is connected to the gas pressure chamber and the second pressure sensor; Pressure rise and fall can be regulated through the pressure regulating mechanism to make the gas density relay body contact action. The contact action is transmitted to the intelligent control unit through the online check contact signal sampling unit. The intelligent control unit detects the action value and/or return value of the contact signal of the gas density relay body according to the density value when the contact acts, and completes the check work without requiring maintainer to go to the site for check. At the same time, because the pressure regulating mechanism is not connected to the SF6 gas path of the gas density relay body or electrical equipment, its sealing requirements are reduced, the reliability of the power grid is improved, and the manufacturing cost is reduced.

The application provides a gas density relay with online self-check function and its check method, including a gas density relay body, a first pressure sensor, a second pressure sensor, a temperature sensor, a gas chamber, a pressure regulating mechanism, an online check contact signal sampling unit and an intelligent control unit. The air path of the pressure regulating mechanism is connected to the gas pressure chamber and the second pressure sensor; Pressure rise and fall can be regulated through the pressure regulating mechanism to make the gas density relay body contact action. The contact action is transmitted to the intelligent control unit through the online check contact signal sampling unit. The intelligent control unit detects the action value and/or return value of the contact signal of the gas density relay body according to the density value when the contact acts, and completes the check work without requiring maintainer to go to the site for check. At the same time, because the pressure regulating mechanism is not connected to the SF6 gas path of the gas density relay body or electrical equipment, its sealing requirements are reduced, the reliability of the power grid is improved, and the manufacturing cost is reduced.

In one example embodiment, a vibration apparatus can augment and enhance negative-pressure therapy systems. The apparatus can be attached to an external surface of a dressing, fluid conductor, or other components. The apparatus can generate low-amplitude vibrations, which can be transmitted through the components. Kinetic energy of the oscillations can agitate fluid in the components, which can lower the viscosity of the fluid and reduce the frequency of blockages in fluid conductors. Vibrations may also agitate a tissue site, which can encourage blood flow and granulation.

In one example embodiment, a vibration apparatus can augment and enhance negative-pressure therapy systems. The apparatus can be attached to an external surface of a dressing, fluid conductor, or other components. The apparatus can generate low-amplitude vibrations, which can be transmitted through the components. Kinetic energy of the oscillations can agitate fluid in the components, which can lower the viscosity of the fluid and reduce the frequency of blockages in fluid conductors. Vibrations may also agitate a tissue site, which can encourage blood flow and granulation.

A switch responsive to a pressure differential, including a pressure response mechanism for providing a pressure response in response to the pressure differential and a device actuator arranged to interact with the pressure response mechanism and to utilize the pressure response of the pressure response mechanism to actuate a device. The device actuator actuates the device to an operative state when the pressure differential is below a lower pressure differential threshold, and may actuate the device to a non-operative state when the pressure differential is above an upper pressure differential threshold.

A switch responsive to a pressure differential, including a pressure response mechanism for providing a pressure response in response to the pressure differential and a device actuator arranged to interact with the pressure response mechanism and to utilize the pressure response of the pressure response mechanism to actuate a device. The device actuator actuates the device to an operative state when the pressure differential is below a lower pressure differential threshold, and may actuate the device to a non-operative state when the pressure differential is above an upper pressure differential threshold.