Abstract: A controller for a heat pump system wherein the controller has a variable capacity control capability that responds to thermostat output signals. The variable capacity controller computes real-time performance parameters at variable capacity heating/cooling load conditions of the heat pump system. A defrost controller calculates an optimum heat pump operating time period between successive defrost cycles during a heating mode of the heat pump. Such values are calculated as a function of sensed time, temperature and variable capacity operating conditions which are calculated by the variable capacity controller. The controller preferably has a manual mode for verifying correct operation of each actuator of the heat pump system, as a function of a sequenced input signal, while the heat pump system is in a shutdown mode.

Abstract: A controller for a gas heat pump system wherein the controller has a variable capacity control capability that responds to thermostat output signals. The variable capacity controller computes real-time performance parameters at variable capacity heating/cooling load conditions of the gas heat pump system. A defrost controller calculates a maximum heat pump operating time period between successive defrost cycles and a minimum heat pump operating time period of each defrost cycle, during a heating mode of the gas heat pump. Such values are calculated as a function of sensed time, temperature and variable capacity operating conditions which are calculated by the variable capacity controller. The controller preferably has a manual mode for verifying correct operation of each actuator of the gas heat pump system, as a function of a sequenced input signal, while the gas heat pump system is in a shutdown mode.

Abstract: Apparatus for measuring loads transmitted via wheels to a track from vehicles travelling thereon, comprises means responsive to load at a plurality of approximately equally spaced locations on a selected portion of the track at least about equal in length to the circumference of a typical wheel passing thereover, for providing a signal that is a function of the largest load on the track from each wheel, means responsive to the signal for comparing each largest load with at least one selected load level, and means responsive to the load comparing means for identifying each wheel from which any load greater than a selected level was transmitted.