Energy harvesting is considered as one of the most promising solution for the power supply of autonomous sensor systems. Two main properties are required: self-powered ability and wideband operation. This article proposes a new self-powered bistable generator which is composed of three parts: the self-powered OSECE (Optimized Synchronous Electric Charge Extraction) circuit, the BSM (buckled-spring -mass) oscillator and two stoppers. The combination of the BSM oscillator and the stoppers allows wideband harvesting capability and the self-powered OSECE circuit with mechanical switches ensures high harvested power and autonomous features. A model of this novel generator is detailed and experimentally validated. As an incremental innovation, better performance is obtained for this new generator compared with the original BSM generator with the standard circuit (without stoppers and mechanical switches). Discussions and optimizations are performed to find the optimal parameters and fully investigate the performance of the proposed generator. It shows that introducing the stoppers and the self-powered OSECE circuit using mechanical switches can substantially enhance the harvested power with moderate additional complexity.