A New Mercury Rheostatic Element for Regulation and Control

The principal design features, along with several typical applications, were described for a new form of mercury rheostatic element which has been designated as the ``Mercurystat´´. The unique features of the Mercurystat are its large number of hermetically sealed mercury contacts and the small force and travel required for their operation. It was shown that relatively large amounts of power can be controlled by the Mercurystat and because of the small input power required for its operation, power amplification in the order of 100,000 can be obtained. The performance of this new device along with its simplicity and absence of wearing moving parts should find many applications for it in automatic control systems.