Alternating current driven piezoelectric latching relay and method of operation

摘要

An alternating current latching relay is provided which employs a latching-type, mechanically operated snap-action switch mechanism with a set of electric contacts that are selectively latched either in the open or closed condition in a snap-action manner upon successive actuations of the snap-action mechanism by suitable push rod means for initiating its operation. At least one alternating current excited bender-type piezoelectric drive member has one end secured to a common base member with the latching-type snap-action switch mechanism and the remaining free end engaging the push rod means. An alternating current electric excitation signal is directly applied to the piezoelectric plate elements of the bender-type drive member for mechanically vibrating the bender-type drive member in a manner such that its amplitude of vibration quickly builds up to a value where it repeatedly strikes the push rod means with sufficient force to selectively actuate the snap-action switch mechanism to the opposite one of its two operating conditions from that in which it originally was set. A tuning mass in the form of a slug element is secured to the end of the bender-type drive member to reduce the natural resonant frequency of vibration of the bender-type drive member to substantially the frequency of the alternating current excitation signal to thereby increase the amplitude of its vibrations to a maximum. Additionally, the tuning mass increases the impulse delivered by the bender-type drive member to the push rod for actuating the snap-action mechanism.