Abstract: Inputs are programmably interfaced and interlocked with output so that the state of the outputs and the operation of equipment connected thereto depends on the hierarchy or priority (control strategy) which is programmed into the controller. The inputs may be contacts (switch closures) of switches which are thrown to operate HVAC units and high or low limit sensors such as thermostats and pressure sensors of an HVAC system. The outputs operate the motor controls of motors which drive the blowers, fans, pumps, dampers and the like of the HVAC system for environmental control and the safety both of the occupants of a facility and the HVAC equipment therein. The programmable controller has an on-matrix and an off-matrix of switch points which are arranged in columns and rows. Each row of switch points is connected to an input circuit. The columns of switch points in the on-matrix are connected to the outputs via control logic to which each column of switch points is connected.

Abstract: A system for metering the flow rate of air through a duct in which gates are pivotally mounted and connected together to vary the area of the duct. The gates are balanced so as to be effectively weightless. The forces on and the position of the gates correspond to the pressure and the flow rate in the duct thereby avoiding the need for air pressure transducers exposed to the pressure in the duct. The forces due to the pressure in the duct are amplified by the gates so that the pressure measurement as a function of the forces on the gates is a much more sensitive function of the flow rate through the duct than is obtainable directly in response to the pressure in the duct (for example, the velocity pressure of air as measured by pressure transducers responsive directly to the velocity pressure in the duct).

Abstract: An assembly for mounting and connecting components, either electrical or pneumatic devices, which are arranged on boards such as printed circuit boards. A channel having a base and flexible side walls receives the edges of the boards in grooves along the side wall. Flexible sidewalls spread apart to receive the boards and lock them in the grooves. Several boards may be located in a channel in end to end relationship. Conduits are defined between the insides of the side walls, the base and the side of the boards facing the base. The components on the boards are located on the outside. Wiring and tubing lines extend through the openings in the boards into the conduits and extend along the conduits. End plates at the opposite ends of the conduits may be used to close the ends of the conduits except for openings through which the wiring and tubing extends.

Abstract: A controller for operating devices adapted for motor control, such as dampers, valves and the like in a heating, ventilating and air conditioning (HVAC) system interfaces with a serial link which may carry control signals for operating a multiplicity of controllers on a time division multiple access (TDMA) basis has digital circuitry responsive to the control signals which translates them into digital signals which are stored between access times. Two series connected pluralities of resistors define, between their opposite ends and their junction points, a potentiometer which is variable by normally open and normally closed contacts which individually are connected across each resistor in each of the pluralities. The switches are operated in response to the digital signals so as to vary the resistance presented by the potentiometer between the opposite ends thereof and the junction.

Abstract: A terminal and gauge assembly which provides connections for lines to or from individual fluid pressure circuits, such as the pneumatic circuits of a pneumatically operated control system includes a duct with a removable cover. The lines run longitudinally inside the duct. A bar located on the cover outside of the duct is formed with spaced chambers. The lines are terminated at couplings which extend into the chambers and serve to fasten the bar to the cover of the duct. Gauges or test points are mounted on the bar and connect to the chambers so that the pressure or other parameter associated with each circuit may be monitored.

Abstract: The efficiency of an environmental control system such as a heating, ventilating and air conditioning system is enhanced and energy is conserved by starting and stopping the heating or air conditioning modes of operation at variable times at the beginning and end of an occupancy period, which times are a function of an environmental condition, such as outside temperature in the case of heating and inside temperature in the case of air conditioning. To this end a control system is provided which generates an output for initiating and terminating the operation of the conditioner. Separate intervals during which the generation of the variable output for initiating the operation of the conditioner and for terminating the operation thereof are established as by means of an arrangement of cams driven by a timer motor which runs during these intervals.