Abstract:
A relay which is operable at very low power levels and which is highly versatile in its applications is shown to be characterized by high gain and high reliability and by simplicity of structure. The relay comprises a first terminal mounted on a base of electrically insulating material and a second electrically conductive member having a terminal portion secured to the base, having a contact arm movable between an open circuit position spaced from the first terminal and a closed circuit position engaging the first terminal, and having integral spring portions connecting the contact arm and terminal portion of the second member for normally biasing the contact arm to one of the noted circuit positions. The relay also includes an actuator wire secured between the base and the contact arm of the second member. The actuator wire is formed of a nickel-titanium alloy and is adapted to be deformed from an original length to a second length as the contact arm is moved to the one circuit position in response to the noted spring bias while the wire material displays a relatively low modulus of elasticity below a transition temperature. The actuator wire is also adapted to abruptly return to its original length and to display a relatively higher modulus of elasticity to move the contact arm to the other circuit position against the spring bias when the wire material is heated above its transition temperature. Means are provided for electrically self-heating the actuator wire to its transition temperature when relay operation is desired.
Abstract:
A miniature remote control circuit breaker in which a movable contact member including a movable contact is engageable with a fixed contact. Motor means, such as a solenoid and an armature actuated thereby, move the contact member from a contacts-open position to a contacts-closed position when the solenoid is energized by remote switch means. Preferably a linkage including two resiliently connected driving members is employed to couple the motor means to the contact member. Condition-sensing (e.g. current-sensing) latch means retain the contact member in its contacts-closed position until the condition sensed varies beyond a predetermined value whereupon the latch means releases the contact member, thereby opening the contacts independently of the energization of the motor means. Further latch means are provided to retain the contact member in its closed position. The latter latch means are responsive to further actuation of the remote switch means thereby to release the contact member and separate said contacts. A further solenoid and armature are preferably provided to effect the release of the further latch means in response to further actuation of the remote switch means.