G04C21/00—Producing acoustic time signals by electrical means
G04C21/16—Producing acoustic time signals by electrical means producing the signals at adjustable fixed times
G04C21/20—Producing acoustic time signals by electrical means producing the signals at adjustable fixed times by closing a contact to ring an electromechanical alarm
G04C21/24—Producing acoustic time signals by electrical means producing the signals at adjustable fixed times by closing a contact to ring an electromechanical alarm put into action by the spring of a mechanical alarm work
Landscapes
Physics & Mathematics
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General Physics & Mathematics
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Switches Operated By Changes In Physical Conditions
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