Pressure switch e.g. for vehicle - has bellows operating moving contact with fixed contacts of bimetallic material to compensate for temperature changes that would result in variations in switching point

摘要

The pressure switch has a pair of fixed contact arms (10,11) with a space between that receives a movable contact (9), the end of which engages the pin (7) of an actuator. The actuator is in the form of a bellows (4) that is pressurised with fluid applied through an inlet tube (5). If the pressure is higher than a reference value the movable contact engages the lower fixed contact (10) and if lower engages the upper one. The fixed contacts are in the form of bimetallic strips that adjust their form to compensate for changes in temperature. ADVANTAGE - Provides compensation for temperature effects.