Abstract: A closed cycle heat transfer device comprising a boiler (10) and a condenser (13), the condenser being used to recover useful heat by latent heat evaporation. A circuit defined by the boiler (10), condenser (13) and ducts (12, 15) is to be liquid-filled at a pressure just above atmospheric pressure. An expansion device (16) maintains the working pressure in the circuit but will receive excess condensate in a liquid phase to compensate for expansion of the working fluid vapor which passes from the boiler (10) to the condenser (13). The expansion chamber contains a movable or flexible member which, when working liquid is received in the chamber, is displaced to compress a gas in the chamber.

Abstract: A voltage regulation device adapted for connection to a varying electrical supply and to regulate the voltage supplied to certain selected circuits whose loads benefit from voltage regulation. The device comprises a PWM or phase angle switched autotransformer which is sufficiently compact and lightweight to be incorporated into a standard electrical consumer unit which has separated circuits, ie, those whose loads benefit from voltage regulation and those whose loads do not, such that the former may be controlled by the device to operate at a constant and reduced voltage thus ensuring a reduction in energy consumption and the life enhancement of the appliances connected to the device. The operating temperature of the autotransformer is controlled by temporarily increasing the output voltage of the autotransformer in the event of overheating.

Abstract: A closed cycle heat transfer device comprising a boiler (10) and a condenser (13), the condenser being used to recover useful heat by latent heat evaporation. A circuit defined by the boiler (10), condenser (13) and ducts (12, 15) is to be liquid-filled at a pressure just above atmospheric pressure. An expansion device (16) maintains the working pressure in the circuit but will receive excess condensate in a liquid phase to compensate for expansion of the working fluid vapour which passes from the boiler (10) to the condenser (13). The expansion chamber contains a movable or flexible member which, when working liquid is received in the chamber, is displaced to compress a gas in the chamber.

Abstract: A voltage regulation device adapted for connection to a varying electrical supply and to regulate the voltage supplied to certain selected circuits whose loads benefit from voltage regulation. The device comprises a PWM or phase angle switched autotransformer which is sufficiently compact and lightweight to be incorporated into a standard electrical consumer unit which has separated circuits, ie, those whose loads benefit from voltage regulation and those whose loads do not, such that the former may be controlled by the device to operate at a constant and reduced voltage thus ensuring a reduction in energy consumption and the life enhancement of the appliances connected to the device. The operating temperature of the autotransformer is controlled by temporarily increasing the output voltage of the autotransformer in the event of overheating.

Abstract: A linear or rotary positive displacement expander (10) is fed by compressed gas or vapour from a reservoir (11) by means of a fast acting pulsed flow control valve (12) actuated by a PWM microprocessor (13) which receives input data from the expander (10) and the reservoir (11) to determine the correct operation of the valve (12). By injecting single or multiple controlled volume pulses of gas into the expander (10), the need for additional pressure regulation between the reservoir (11) and the expander (10) is eliminated, and the expander can operate efficiently within its built-in pressure ratio capability whereby the gas or vapour is expanded to be as close as possible to ambient pressure at the outlet of the expander.