| 摘要 |
An improved magnetic switch (10) is provided which is designed for use in an alarm circuit (52) in order to detect relative movement between first and second members such as a door (14) and frame (12), so as to signal unauthorized opening of the door (14). The switch (10) includes a switch assembly (20) for mounting in frame (12) and having first and second switch elements (40, 42), an electrically conductive, shiftable body (44) adjacent the elements (40, 42), and a first attractive component (45). Additionally, the switch (10) has a second attractive component (22) for mounting to the door (14). In use when door (14) is closed and circuit (52) is armed, the magnetic attraction between body (44) and component (22) shifts the body (44) to a switch position where the body (44) is out of simultaneous contact with the switch elements (40, 42). If the door (14) is opened, the magnetic attraction between body (44) and component (45) moves the body to another switch position establishing simultaneous contact with the switch elements (40, 42). |
