. The Bell System technical journal . arionsnumbers of ampere turns in the winding. The load and pull chart provides a comprehensive picture of over-allrelay performance. For example, starting from the released position,the force or back tension, holding the card against the core is about 140grams. Following the upper curve, the spring load increases slowly asthe armature mo\es toward the core, until the first contacts make at aload of about 200 grams. The load increases rapidly as the remainingcontacts are closed until the last contacts are closed at about 650 travel of the arma
. The Bell System technical journal . arionsnumbers of ampere turns in the winding. The load and pull chart provides a comprehensive picture of over-allrelay performance. For example, starting from the released position,the force or back tension, holding the card against the core is about 140grams. Following the upper curve, the spring load increases slowly asthe armature mo\es toward the core, until the first contacts make at aload of about 200 grams. The load increases rapidly as the remainingcontacts are closed until the last contacts are closed at about 650 travel of the armature to the operated position increases thespring load to a final value of about 700 grams. As the armature isallowed to return to the original position, the lower curve is area between the two curves is a measure of mechanical hysteresis,or friction, in the relay. This energy loss is a very small fraction of thespring load at all values of armature travel. The pull curves show ampere turns necessary to assure operation of. LEAKAGE RELUCTANCE SHUNT Fig. 13 — Core assembly for replaceinent type relays showing leakage reluc-tance shunt. 1 1126 THE BELL SYSTEM TECHNICAL JOURNAL, SEPTEMBER 1954 w \\ \\ PULL-350NI 800 \ \ \ \ \ \\ \ \ \ \\\ LATE \ \L -150 N^ 100 \ CON\ (M RLV ^^ TACTS-> ^AKE) 1 ^ BACKTENSION ^-^~-- ^- 1- -50 0 \\ OPERATEDPOSITION ARMATURE TRAVEL fIN INCHES I RELEASEDPOSITION Fig. 14 — Typical load and pull characteristics of a 30-contact fast relay. the relay. The maximum ampere turns required are determined by thecritical load point. This occurs at inch armature travel andabout 650 grams. Under static conditions, therefore, 160 ampere turnswould be required for complete operation. Circuit uses for these relaysdo not include nonoperate, hold, or releas
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
