Abstract: The railroad power switch operates from the energy stored in a hydraulic accumulator. A pump charges the accumulator and keeps it charged. A power cylinder acts on the moveable rail of a railroad switch through this hydraulic energy. The energy opens the switch, closes it, and stabilizes it during train trailing through the switch. A spring pack supplements this hydraulic energy in stabilizing the switch.

Abstract: A programmable thermostat for use with air conditioners or heat pumps.Two (2) programmable timer-counters determine the respective amounts of time that the compressor will and will not operate. Both timers are consumer controlled. The "on" timer initiates compressor operation at the beginning of its cycle, and activates the "off" timer at the end of its cycle. The "off" timer stops compressor operation at the beginning of its cycle and activates the "on" timer at the end of its cycle.Operation of the "off" timer can be overridden by a "satisfied/not satisfied" means which re-starts the "on" timer at the end of its cycle if certain monitored conditions have not attained a preselected threshhold value.Filtering means are also provided so that the "on" timer responds only to genuine calls for service from the thermostat.

Abstract: An apparatus is provided for detecting the quantity of a specific gas hereinafter simply called "gas" in a carrier gas when water vapor is present. The gas and the carrier gas are passed through a whistle chamber which produces a resonating frequency. The resonant frequency changes as a function of the fraction of the gas, temperature and water vapor. An output signal is produced which is a function of the resonant frequency. A correction device senses water vapor and temperature and produces an output signal which is a function of the water vapor and the temperature. A receiving means receives the output signals and produces a resultant signal which is a function of only the fraction of the gas.

Abstract: Method and apparatus for controlling the amount of outside air introduced into a given space being ventilated as a function of the oxygen content of the air in the space to minimize the energy expended in heating or cooling air flowing through the space while maintaining the oxygen content of the air above that required for the well-being of humans occupying said space. A fuel cell produces an electric current the magnitude of which is a function of the partial pressure of the oxygen present in the air surrounding the fuel cell. The output of the fuel cell is applied to a control circuit which applies control signals to the motor control circuit of a damper motor to admit outside air when the partial pressure of the oxygen in the occupied space falls to a predetermined minimum level and to exclude outside air and to recirculate return air when the partial pressure of the oxygen in the space rises to a certain maximum level.