by closing a contact to put into action electro-acoustic means, e.g. awakening by music

Full Title

Producing acoustic time signals by electrical means > producing the signals at adjustable fixed times > by closing a contact to put into action electro-acoustic means, e.g. awakening by music

Classification Context

Section:

PHYSICS

Class:

HOROLOGY

Subclass:

ELECTROMECHANICAL CLOCKS OR WATCHES