Abstract: A hot water heating system powered by a gas burner uses the output signal of a heat consumption meter measuring the amount of heat flowing to heating radiators for controlling the heat capacity or heating power of the burner. A control signal dependent on the demand of heat is fed to a solenoid operator of a servopressure regulator and the required amount of air for achieving optimum combustion is supplied via an air control valve which receives its input signal from an oxygen or carbon dioxide sensor in a burner stack.

Abstract: A differential pressure responsive switch utilizes an operating diaphragm which has a position controlled by a pressure being monitored with the diaphragm acting through a transmission member upon an electrical switch and includes a first chamber divided by a control diaphragm and having an inlet for the pressure to be monitored to one side of the control diaphragm while the other side of the control diaphragm carries a closure member for an adjacent bleed valve seat. An inlet for the bleed valve is connected via a throttle to a source of a pressurized gas and to a second chamber defined by the operating diaphragm and a spring is engaged through the transmission member to urge the operating diaphragm against the pressure in the second chamber.

Abstract: A control method uses a room thermostat for generating an output signal representative of an energy demand and an energy source which can be cyclically switched on and off and includes the steps of determining within a switching cycle of the energy source the actual switch on period, comparing the actual switch on period with an adjustable desired switch on period within the cycle to produce a control signal representative of the energy demand and controlling the energy source in accordance with the control signal.

Abstract: In a control system for a gas heated water or air heater, the use of the supplied fuel gas is to be improved by automatically determining and supplying the amount of air which is required for obtaining complete combustion. A gas control valve feeds a burner with the required amount of gas dependent on the demand of heat. A sensor responding to the content of oxygen or carbon dioxide within the flue gases is located in the stack and the output signal of this sensor is compared with a set point within an electric controller. In case of a control deviation, the output signal of the controller controls an adjustable source of air under pressure formed by a fan with subsequent air control valve in such a manner that the required amount of air for reaching optimum combustion is supplied.

Abstract: A diaphragm operated pressure regulator having jointly operable principal and auxiliary springs, the auxiliary spring being readily exchangeable to vary the control characteristic of the regulator without affecting the maximum and minimum pressure adjustments of the regulator.

Abstract: A pressure regulator has a diaphragm controlled valve and a temperature responsive means for adjusting the loading on the diaphragm to provide a pressure control from a maximum pressure to a minimum pressure in a modulating manner as the temperature changes. The temperature responsive means operates a lever for varying the spring loading on the diaphragm which is accomplished by a resilient biased pin and a C-shaped spring so that when the pin is lifted by the lever to reduce the force on the C spring, the C spring provides for a broadening of the force on the diaphragm and thus widening the modulation range of pressure for a given range in temperature.