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THE BELL SYSTEM TECHNICAL JOURNAL, MAY 1957 



6 4 2 2 4 6 



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ARMATURE POSITION IN LINEAR MILS 



Fig. 11 — Resultant forces on armature of J-7 valve. 



quired to move the armature in breaking the friction of the stationary 

 armature assembly. Thus, the signal threshold is reduced by the amount 

 of the dither current and the resulting increase in sensitivity to small 

 signals greatly reduces the phase lags at low amplitude. 



STEADY STATE HYDRAULIC CHARACTERISTICS 



The J-7 valve is designed to operate from an oil supply having a pres- 

 sure of 2,000 psi, which is somewhat higher than eaily valves of this 



