Abstract: Method and apparatus by which continuously existing analog voltage command signals for various channels within a control system are changed by determined amounts and senses as a result of supplying "pulse" signals of different durations and polarities. Electronic integrators preferably operating to create linear slope changes in their outputs, and to hold their outputs steady absent any input, are receptive to the change signals ("pulses") of differing durations to create analog command signals which change by increments proportional to the time duration and in a direction corresponding to the polarity of the change signal. This permits computer control of servo devices requiring continuously-existing, changeable command signals in the same fashion as servo devices which respond directly to variable duration, pulse-type change signals.

Abstract: A position detector providing an electrical position feedback signal proportional to relative mechanical movement between two elements employs a hall effect device to sense changes in magnetic flux density resulting from relative movement of the hall effect device with respect to an adjacent magnetic field, the hall effect device producing an electrical signal proportional to magnetic flux density which signal comprises the electrical position feedback signal. The hall effect device and magnet are supported in respective relatively movable members in cooperative relationship such that the magnet is adjacent the hall effect device so as to permit relative movement of the hall effect device with respect to the magnetic field, the members being preferably adapted for mounting respectively on two relatively movable mechanical elements.

Abstract: Incremental heating and cooling sources are energized and deenergized as required to meet the maximum heating and cooling demands of any of the zones in a temperature controlled space. Common references and comparators are employed for both heating and cooling controls.

Abstract: Incremental heating and cooling sources are energized and deenergized as required to meet the maximum heating and cooling demands of any of the zones in a temperature controlled space. Common references and comparators are employed for both heating and cooling controls.