Thermal engine

The power source heat engine uses an enclosed working gas arranged between two temperature ranges and has three heat exchangers (1A-C) each with a single connection via a pipe (4A-C) to a working cylinder (2). Each heat exchanger is connected by a valve (5A-C) to the cylinder. The heat exchangers have hot and cold surrounding flows. The working cylinder can have a piston (3) operated by expansion and compression of the working gas.