Johnson Service Company

Jon Harold Bechtel

Thomas E Hayes

Robert E Emmons

An humidistat has an element movable in response to ambient relative humidity operatively connected to a core of a linearly variable differential transformer for moving the core. The core is supported within a body portion of the transformer for minimal friction of movement relative to the body portion. The body portion has a primary winding and two secondary windings. An oscillator excites the primary winding to provide output signals from the secondary windings proportioned to movement of the core in the body portion and, therefore, indicative of the relative humidity sensed by the element.

Humidistat

A proportional plus integral controller connectable in a conventional proportional control loop of a process control system is selectively operable in a proportional only mode or a proportional plus integral mode in accordance with the positioning of a mode select switch and exhibits substantially bumpless forward transfer from proportional only to proportional plus integral operating modes.

Growing community of inventors

Goshen, IN, United States of America

Jon Harold Bechtel