Pressure switch

A pressure switch is a form of switch that makes electrical contact when a certain set pressure has been reached on its input. This is used to provide on/off switching from a pneumatic or hydraulic source. The switch may be designed to make contact either on pressure rise or on pressure fall.

Examples

Pneumatic

Uses of pneumatic pressure switches include:

• Switching off an electrically driven gas compressor when a set pressure is achieved in the reservoir
• Switching off a gas compressor, whenever there is no feed in the suction stage.
• in-cell charge control in a battery
• Switching on/off an alarm light in the cockpit of an aircraft if cabin pressure (based on altitude) is critically low.

Hydraulic

Hydraulic pressure switches have various uses in automobiles, for example:

• To switch on a warning light if engine oil pressure falls below a safe level
• To switch on brake lights automatically by detecting a rise in pressure in hydraulic brake pipes
• In dust control systems (bag filter), a pressure switch is mounted on the header which will raise an alarm when air pressure in the header is less than necessary to gain or decline energy beyond the set value

See also

Pressure sensor