| 摘要 |
A door alarm system comprises a door having a doorframe, a door body and a door alarm device mounted in the doorframe or door body. The door alarm device comprises a housing, a cover mounted on the housing and having a rear surface, a push button hole and four guideposts formed on and protruding from the rear surface, a battery compartment, a push button and a controller. The push button is mounted slidably in and protrudes from the push button hole and has a cap with a neck, an electrical pad mounted on the guideposts and having a through hole, a metallic plug and a resilient member. The metallic plug is mounted through the through hole in the electrical pad, connects to the neck and selectively makes contact with the electrical pad when the door is open. The controller mounted in the housing and provides an audible warning when the door body is open.
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