Abstract: A central control system includes a central processing unit (CPU) installed in a central location of a facility, and interconnected with a plurality of remote controllers, each located in an associated one of several buildings in the facility and each including a remote microprocessor (RMP), the CPU automatically controlling, simultaneously from the central location, the closed loop operation of individual environmental conditioning systems in the several buildings comprising the facility in combination with the RMP associated therewith and in dependence on the sensed temperature conditions within the living spaces associated with each system.

Abstract: Electronic processing means, in combination with dedicated sensing apparatus is used to control the operation of an HVAC system which regulates the temperature in one or more temperature controlled spaces. The electronic processing means and associated sensing apparatus being readily adapted to existing HVAC systems through interface apparatus installed in each of the existing HVAC control lines associated with the HVAC sources of mixed air, hot air, and cold air, to provide selective actuation and modulation of the discharge air temperature from each source, individually or in combination, in response to sensed HVAC parameters including source discharge temperatures, space temperatures, outside air temperature, and the relative humidity of the outside air and return air from the spaces.

Abstract: Apparatus for controlling the discharge temperature of thermal fluid presented from a common thermal source to one or more HVAC systems in a network, each HVAC controlling the volume of thermal fluid circulating therethrough by regulating the valve position of HVAC valve apparatus over a valve position range from a full closed position to a full open position in dependence on the thermal energy level required by one or more temperature regulated living spaces associated with each HVAC, the apparatus including electronic processing means in combination with dedicated temperature and valve position sensing apparatus for providing actual position signals for each fluid valve apparatus and an actual source discharge temperature signal, the electronic processing means determining the magnitude of the greatest thermal energy demand within a short term interval in dependence on the most open of the actual valve position signals and providing modulation of the source discharge temperature over the short term interval

Abstract: The differences between two pairs of the three windings of a synchro stator are individually scaled so as to provide a function of the rotor angle plus a 45.degree. phase lead. The scaled values are applied to a CR/RC bridge, the output of which bears a phase relationship relating directly to the synchro rotor angle, but is identical for shaft angles from 0.degree. to 180.degree. and from 180.degree. to 360.degree.. These signals are shaped and applied to a pulsewidth modulator; the pulsewidth modulation ambiguity is resolved by generation of a sign bit indicative of angles between 180.degree. and 360.degree.. The pulsewidth modulated output is converted to an analog level, as is the reference supply voltage, and an analog to digital converter provides a digital output as a function of the ratio of the angle voltage level to the reference voltage level. The sign bit is provided as an additional digital bit thereby providing a digital output indication of shaft angle.