The acoustic waves consist of alternating pressures and flows. The used generator is a linear generator that converts acoustic waves into electric power. The linear movement of the generator is limited; exceeding these limits might damage the generator. The total system, consisting of the thermoacoustics engine, generator and load, is tuned to get acoustic waves with the desired frequency and amplitude. A source with a temperature difference delivers the heat power to the system. This temperature difference changes in time. The power delivered depends on the input power and the loading of the system. To avoid destruction of the generator, the movement of the generator has to be controlled. The load should also be controlled to maximize the output power.