Abstract: A system for controlling make-up air apparatus for a controlled building space includes a first sensor for sensing the operation of a first appliance within a building space. The appliance causes the air to be exhausted from the controlled building space. There is a controller which receives a first signal from the appliance indicating that the appliance is activated. This signal is used to determine the air flow requirements between the controlled building space and an environment outside of the controlled building space such as to ensure a predetermined balance of the pressure of air within the controlled building space and the environment outside of the controlled building space. An air temperature sensor monitors the outside temperature. A back-flow damper and a preheater are also associated with the make-up air apparatus. A switch activates the preheater in the event that the temperature of outside air is below a predetermined level. The motor of a blower causes air to be drawn into the building space.

Abstract: A process for performing real-time cascade control for use in controllers. An adaptive process module uses an algorithm to set parameters during system operation to attain the best possible control performance, while providing an easier-to-use system for the user. The algorithm uses a novel adaptive technique to intelligently adjust the minimum and maximum allowable controlled-variable set point limits, under varying load conditions.

Abstract: A method of controlling humidity within a space, where the space communicates with humidity control equipment. The method comprises determining a dew-point temperature within the space, and comparing the dew-point temperature to a predetermined desired dew-point temperature. The humidity control equipment is then controlled based upon the difference between the dew-point temperature and the predetermined desired dew-point temperature. The humidity control equipment can be a humidifier, and the dew-point temperature can be determined by sensing the temperature and humidity within the space, or by sensing the temperature and humidity within a duct, such as a return air duct.

Abstract: A method of communicating between a plurality of devices in a controller area network is disclosed. The method includes a first device transmitting a first message over the network, a second device comparing a first value in the first message with a second value, and a third device responding to messages it receives over the network. The method may involve a number of producer devices and a consumer device. The consumer device responds to messages sent as instance zero. The method may involve a number of producer devices, an intermediate consumer and a consumer device. The producer devices send their messages as instances other than zero. The intermediate consumer receives the messages from the producer devices, compares them, and sends messages as instance zero to the consumer device. The producer devices may be thermostats, actuators, sensors, etc. The consumer device may be a furnace, an air conditioner, etc.

Abstract: A solid state power supply circuit for providing high frequency power to ignite oil or gas and operate neon sign transformers. A switch operates in conjunction with a resonant tank circuit to supply power to the resonant tank at a predetermined time. The timing of the pulse is controlled to occur when the operation of the transistor will result in providing maximum energy to the load while minimizing power dissipation in the transistor. An amplifier and clamping circuit also operate to limit the duration of the pulse to further reduce power dissipation in the switch.

Abstract: A control unit such as a thermostat has a subbase which mounts on the surface holding the control unit and has electrical terminals for connecting to an operating unit. A controller is designed to mechanically attach and electrically interface to the subbase. The subbase has a memory unit which can record a number of different digital values. Each of these digital values corresponds to an operating unit requiring a different configuration of control algorithms. The controller receives the value recorded in the subbase memory unit and configures its control algorithms according to the value provided from the memory unit.

Abstract: A bent crankshaft assembly for motorized valves. The crankshaft is formed having three distinct regions, a connection region, a bend region, and a sphere retaining region. These regions are formed in a unitary rod without staking or milling operations.

Abstract: An air duct has a filter mount opening originally intended to accept a shallow filter element for filtering air entering the duct. The opening has an interior flange whose original purpose was to support the shallow filter element. This flange has interior edges defining an air passage opening. The invention is implemented a filter unit including a frame and a deep filter element mounted in the frame. The frame has dimensions allowing the filter unit to replace the conventional shallow filter element with the frame inserted into the air passage opening and closely spaced to all of the interior edges. A resilient gasket is mounted adjacent to the opening's interior flange and projects slightly into the air passage opening so as to contact the deep filter element's frame. The gasket prevents air leakage between the interior flange's interior edges and the frame.

Abstract: A thermostat for use with multistage Heating, Ventilating and Air Conditioning (HVAC) plants where a proportional/integral control loop is present for each stage of the multistage HVAC plant. Filter constants, Ki and Kp as well as stage control points and interstage values can be set independently for each stage.

Abstract: In a comfort controls system for multiple buildings (whether residential, commercial or industrial), a weather forecast unit sends weather forecast data over the Internet to a building management provider which handles building management services for a number of clients, each having a number of buildings and properties.At the provider's reception station, data on the external-building characteristics of all the buildings are compiled with the received data and then fed to the appropriate building management controls system.