Abstract: A method of detecting a fault of an exhaust gas recirculation system of an internal combustion engine, comprising detecting a temperature relating to a temperature of a gas recirculating through the exhaust gas recirculation system when the system is in a condition in which the system should be operated to return part of an exhaust gas of the engine to an intake passage, and detecting that the exhaust gas recirculation system is defective when the detected temperature is lower than a fault discriminating value. A condition of air to be sucked into the engine, such as intake air temperature and atmospheric pressure, is detected, and the fault discriminating value is set in accordance with the detected air condition, whereby abnormality or fault of the exhaust gas recirculation system can be detected accurately and reliably.

Abstract: Disclosed is a centralized home appliances simultaneous control system consisting of controller(s) and terminal units associated with home electric appliances. Setting of batch control is done in a centralized manner on the controller(s) and it is stored in the memory provided in the controller(s), instead of being done on the individual terminal units. The settings stored in the controller's memory are sent via a communication medium to the memory in each terminal unit, and the setup status of each terminal unit is sent back to the controller(s) for the purpose of monitoring with reference to the contents of the controller's memory. A batch control command signal is issued from the controller(s) to the terminal units, which then responds to control the operation of the associated electric appliances in accordance to the batch control plan corresponding to the command held in the memory of the terminal units.

Abstract: A burner system adapted to vaporize liquid fuel, generally kerosene, and burn gaseous fuel in blue flames includes an evaporator heated by a heater to about 250.degree.-300.degree. C. to vaporize the kerosene. The evaporator is thermally insulated from a premix passage and a burner, to reduce the time required for preheating the evaporator. At the time of ignition, the volume of a portion of primary air supplied to the evaporator is reduced below the corresponding volume supplied in maximum combustion condition and the volume of the kerosene supplied to the evaporator is substantially equal to the corresponding volume supplied in maximum combustion condition. This enables a premix of liquid and air within a combustible limit to be supplied to flame ports even if part of the premixture forms dew in the premix passage, and allows an enriched premixture to flow out of the flame ports at low velocity to facilitate ignition.

Abstract: Disclosed is a method of operating an air conditioner having a plurality of indoor units connected to a common outdoor unit as heat source machine. When operation of a plurality of indoor units is dictated depending upon the temperature differences between the room temperatures and the set temperatures therefor, the indoor unit having the smallest temperature difference is determined among those indoor units which are to operate, and the amount of heat exchange is limited in the indoor unit having the smallest temperature difference to advantageously perform air conditioning in respective rooms in which the indoor units are provided.