A pressure responsive switch senses a change in pressure and responds to such changes by alternately making and breaking an electrical connection. Pressure-sensitive switches are used in a variety of applications where it is desired to switch apparatus on or off at predetermined pressures. These switches are utilized in a wide variety of applications, as in automobiles [pic]
, aircrafts and in various other environments. Pressure switches include set-point pressure switches that actuate when a specified pressure is reached and pressure measuring switches that are capable of measuring the ambient pressure and reacting accordingly. A pressure responsive switch generally comprises a diaphragm responsive to a pressure change, a rigid ring for securing the diaphragm, and a pair of electrically conductive contacts that break contact based on movement of the diaphragm. Mechanical pressure switches typically provide an output signal in the form of a switch closure in response to application of mechanical or atmospheric pressure. A differential pressure switch [pic]
is a device which utilizes differential fluid pressure from low and high pressure sources to actuate an electric switch at a pre-set actuation point. Differential pressure switches are commonly employed to control the operation of snap action switches.
A flow switch is used to sense the flow of a fluid passing through its valve body and to send an electrical control signal to control the switching unit. In many applications, it is essential to be able to determine whether fluid is flowing in a pipeline, duct or other conduit and to respond accordingly to such a determination. For example, flow responsive devices for producing a control signal which is used to de-energize a pump when the flow rate falls below a preselected minimum are commonly employed in systems for transferring fluid between reservoirs. Fluid flow switch...