A pulse combustion device has a number of combustors with upstream bodies and downstream nozzles. The device is decoupled from the seat belt webbing in response to the tension in the seat belt webbing exceeding a predetermined threshold. Preferably three such zones are provided in succession in the direction of displacement of the perforated belt. Therefore, the charging target can be charged to a higher voltage even though a charging voltage of the charging target is low. In another implementation, the domain names are transmitted to the browser program by embedding the domain names in a web document, in which the embedded information is not visible in the rendered version of the web document. The battery has an equivalent series resistance that varies inversely with temperature.