Abstract: A comfort control system for controlling the comfort level in a building includes a comfort control unit and a remote control unit. The remote control unit communicates with the comfort control unit from a remote location. In one illustrative embodiment, the remote control unit includes a temperature sensor for sensing an ambient air temperature near the remote control unit, and a measure related to the sensed temperature may be communicated to the comfort control unit. A detection block may be included in the remote control unit for detecting when the ambient air temperature sensed by the temperature sensor in the remote control unit is likely to be influenced by a user or other undesirable condition. The comfort control unit may take this into account when controlling the comfort control system of the building.

Abstract: A comfort control system for controlling the comfort level in a building includes a comfort control unit and a remote control unit. The remote control unit communicates with the comfort control unit from a remote location. In one illustrative embodiment, the remote control unit includes a temperature sensor for sensing an ambient air temperature near the remote control unit, and a measure related to the sensed temperature may be communicated to the comfort control unit. A detection block may be included in the remote control unit for detecting when the ambient air temperature sensed by the temperature sensor in the remote control unit is likely to be influenced by a user or other undesirable condition. The comfort control unit may take this into account when controlling the comfort control system of the building.

Abstract: Methods and apparatus for controlling a climate control system for an enclosure, including a controller for operating a cooling system and a humidification system. The cooling system is operated to maintain the temperature of the air within the enclosure at a specified value, and the humidification system is operated to maintain the humidity of the air within the enclosure at a specified value. Provisions are made to help ensure that the humidification system does not provide water to the air during periods when the minimum value of the temperature of the air provided by the cooling system is below the dew point temperature of the air.

Abstract: Methods and apparatus for controlling a climate control system for an enclosure are described. The invention includes a controller for operating a cooling system and a humidification system. The cooling system is operated to maintain the temperature of the air within the enclosure at a specified value, and the humidification system is operated to maintain the humidity of the air within the enclosure at a specified value. Provisions are made to help ensure that the humidification system does not provide water to the air during periods when the minimum value of the temperature of the air provided by the cooling system is below the dew point temperature of the air.

Abstract: A humidity control system for an enclosure requiring heat from a furnace and having one or more windows, includes sensors for the enclosure temperature and humidity, and a means for measuring the percentage of time which the furnace is operating (load factor). The system estimates the interior window temperature based on these parameters and controls humidity added to the enclosure air to prevent the enclosure air dew point temperature from rising above the estimated window temperature. This prevents condensation on the window surfaces. The estimation can be adjusted to compensate for different insulation characteristics of the window. In a preferred embodiment, the enclosure air temperature and humidity are derived from sensors conveniently located in the return air duct.

Abstract: A communication system comprises a remote switching module having two signal terminals connected by just two conductors to the signal terminals of a local decoding module. Power is directly provided only to the local decoding module, which applies DC voltage of a first level across the conductors. The remote switching module has a voltage regulator which provides power of a second voltage level lower than the first level for operating a control unit in the switching module. The control unit controls a variable impedance having higher and lower impedance levels and which is connected across the switching module's signal terminals. The decoding module can detect the different impedance levels by sensing the current flow on the conductors. The switching module communicates with the decoding module by modulating the time intervals between changes in impedance levels.

Abstract: An apparatus and method for providing a microprocessor having an inaccurate oscillator with a desired time base. The cycles of the output signal of the oscillator are counted by a first counter until the counted number equals a predetermined correction count. The first counter then produces a timing signal. A second counter is set up to create an actual count indicative of the number of output signals occurring during a predetermined number of periods of an AC signal generator connected to the microprocessor. A predetermined desired count is then subtracted from the actual count to produce a difference count. The difference count is then added to the old correction count to create a new correction count. By iterating this process until the difference count is equal to zero, the timing signal is modified until it is equal to the desired time base.

Abstract: A low voltage monitor and microcontroller output monitoring circuit for insuring proper operation of a microcontroller in a furnace control system. A switch connected to a reset port of the microcontroller is capable of putting either a high or low voltage signal at the reset port. A high signal is required for normal operation of the microcontroller. The low voltage monitor connects to a power supply providing power to the microcontroller and causes the switch to provide a low signal to the reset port if the output voltage of the power supply drops below a predetermined level. The output monitoring circuit insures that the microcontroller is operating properly by insuring that the microcontroller is producing an output signal at a predetermined frequency and repetition rate. If the output signal is not at the predetermined frequency, the output monitoring circuit causes a low voltage to be present at the reset port.

Abstract: A microcontroller and system allowing for more than one trial time in a furnace system, while using only one pin of the microcontroller. An alternating current signal at an input port of the microcontroller causes the microcontroller to allow a first long trial time period. Any direct current signal at the input port causes the microcontroller to allow only a second shorter trial time period. The trial time input port of the microcontroller is placed between two ports which either receive or send direct current signals. Due to this arrangement of the parts and construction of the microcontroller, the microcontroller will fail to the shorter and safer trial time if a fault causes an erroneous signal to appear at the input port.

Abstract: A reference frequency and low voltage detector circuit for use with a constant frequency A.C. voltage source is disclosed in which a first supply circuit supplies a first voltage wave form having a repetition rate and magnitude proportional to the A.C. source voltage. A second supply circuit supplies a regulated D.C. voltage of a fixed magnitude as long as the amplitude of the A.C. source voltage is normal. The voltages produced by the first and second supply circuits are supplied to noninverting and inverting input terminals of a differential amplifier which produces a rectangular wave output signal only when the A.C. source voltage is normal. The differential amplifier output signal provides a frequency reference under normal conditions and signals a user device to switch to a secondary mode of operation when the repetition rate of the rectangular wave form changes.

Abstract: An air conditioning system furnishing temperature conditioned air to a plurality of zones each of which has its own zone damper controlled by its own space thermostat. The system has an air discharge temperature sensor downstream of the temperature conditioning heat exchanger which is connected to a microprocessor controller for controlling a plurality of stages of temperature conditioning apparatus such as heating or cooling apparatus and a damper motor control for controlling the entry of outdoor air into the system.