The principle of a pressure switch mainly relies on the use of gas or liquid pressure to activate the electrical contacts of the switch. Specifically, its working principle is as follows:
Structural Composition: A pressure switch is mainly composed of a motive or pressure-sensitive element (sensing external pressure), a mechanical linkage mechanism (transmitting pressure), and a microswitch (actuating actions through normally open and normally closed contacts).
Working Process: When the motive element is subjected to external gas or liquid driving pressure, this pressure needs to be sufficient to overcome the elastic force of the compression spring. Once this condition is met, the pressure will push the piston rod upwards, causing the microswitch to actuate. This action manifests as the opening of the normally closed contacts and the closing of the normally open contacts, thus controlling the on-off state of the circuit.
Reset Process: When the external pressure disappears or decreases, the piston will separate from the microswitch under the action of the spring, resetting the contact system.
In addition, pressure switches may utilize different types of elastic elements, such as single-coil bourdon tubes, diaphragms, bellows, and corrugated tubes, as well as various switching elements, including magnetic switches, mercury switches, and microswitches. The choice of these components depends on the specific application and requirements.
Overall, a pressure switch is an electrical contact device that detects and controls the pressure of gas or liquid to achieve on-off control of electrical circuits. It has widespread applications in industrial automation, process control, and other fields.
