Humidity and temperature responsive switch

摘要

A humidity-biased temperature responsive switch for controlling an automobile air conditioning compressor which closes at a warmer ambient temperature when the humidity is low than when the humidity is greater. The switch includes a sensor element having a metal strip and a hygroscopic plastic strip laminated together so that the different thermal coefficients of expansion will cause the free end of a cantilever- mounted sensor to move a contact. Absorption of water from the ambient air causes the plastic to swell and elongate and resultantly moves the contact into a closed position at a lower temperature than when the humidity is low.