File:Bell telephone magazine (1922) (14753816394).jpg

Identifier: belltvol20elephonemag00amerrich (find matches)
Title: Bell telephone magazine
Year: 1922 (1920s)
Authors: American Telephone and Telegraph Company American Telephone and Telegraph Company. Information Dept
Subjects: Telephone
Publisher: (New York, American Telephone and Telegraph Co., etc.)
Contributing Library: Prelinger Library
Digitizing Sponsor: Internet Archive

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IGN particles have been a fre-quent source of relay trouble. Theair is full of minute objects: drops ofmoisture, bits of hair, soot and coal,metallic particles, fibers of cotton,silk, and wool. With the thousands ofrelays in a central office, it is not sur-prising that at times one of these float- ing particles should lodge on a contactsurface and prevent proper closing ofthe contacts. To diminish troubles from thissource, individual covers have beenused to keep the dust away, the con-tacts have been mounted in verticalplanes to minimize accumulation ofdust by settling, and air filteringequipment has been used in somecases. A recent improvement whichis very effective is a relay spring hav-ing double contacts. The advantage of twin contactsover the former single contact can beillustrated by an extreme example ofatmosphere wherein dust particles areso dense that at every thousandthoperation a contact, when pressedagainst its mate, will close over apiece of dust or lint, and thus fail to
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