PRESSURE SWITCHES SPDT
In industrial and automotive applications, it is frequently necessary that, when the pressure setting is reached, this is converted into an electrical signal that starts a machine cycle or indicates a certain situation (e.g. system leaks or alarms).
These operations are generally controlled by components, called PRESSURE SWITCHES, that are calibrated according to the specific application.
Pressure switch SPDT contacts
A switch can be calibrated using a set screw which, by acting on a calibration spring, determines its load. The spring opposes the thrust of the pressure exercised by the fluid on the sensitive element (a membrane or piston), allowing the electrical contact to close or open only when the pressure setting is reached.
In the SWITCHING CONTACTS (SPDT) of Fig. 3 version, the presre of the fluid on the separating element (diaphram or piston) causes a microswitch to switch. Either NC or NO contacts, or both, can be used in this version.