# A Robust Generator-Harvester for Independent Sensor Systems +
## 5 Conclusions  
Based on our experience with numerical models and related experiments with a microgenerator as a source of renewable energy, we have proposed the design of a powerful motion-excited linear generator to first approximate the expected results with a linear reciprocating engine driven by compressed gas. The design was modified to deliver high efficiency in converting kinetic energy into electricity, the performance having been expected based on previous experience [19,20].  
Relevant experiments on a scale model demonstrated the feasibility of implementing such an energy conversion system as a harvester using a renewable form of energy. The numerical model and the analysis of the model parts significantly accelerated the geometrical design of the arrangement of the key parts of the electric generator. The selected variants of the magnetic circuit layout were experimentally verified, as was also an increase in the harvester yield through a double-acting arrangement of the magnetic circuit. After miniaturizing the cells and multiplying them, we evaluated the concept as a convenient alternative source of energy for both sensors in structures, including bridges, and motor vehicle systems. The experiments have proved that, in the harvester, the magnetic circuit configuration embodies the key factor for achieving the energy transformation yield; this fact has been largely neglected thus far. Further, changing the magnetic circuit, with a comparable electrical load, produces an up to 50-fold increase in the output voltage; at the given electrical load, this then indicates a 2500 times higher output power (Table 2, type I and type III @ \(Z_{1,Re}=150\)\(\Omega\)). Future research will focus on interfacing the harvester with sensor systems, completing the periodic arrangement of the segments, and measuring the overall efficiency of the generator.  
Figure 8: The concept of a periodically arranged harvester: (**a**) from segments with the required expected parameters, power in the band \(P=10\)–\(10\),\(000\)\(W\); (**b**) an example of the linear generator design [48].  
The impact of the investigation and experimenting herein lies in characterizing an approach to arrange the magnetic circuit within the linear configuration of a generator in such a manner that a substantially higher volume of electricity is extracted under load and mechanical energy inputs that are equivalent to standard conditions (see Figure 3, type III). These relevant solutions, to the best of our knowledge, have not been fully considered or published to date.  
[PERSON] and [PERSON] contributed to the theoretical part, numerical modeling, and design of the experiments, and they also co-wrote the paper; [PERSON] and [PERSON] conceived and designed the experiments that allowed for the partial verification of the effects; and [PERSON] with [PERSON] modified the manuscript graphically and participated in evaluating the experiments. All authors have read and agreed to the published version of the manuscript.  
The research was funded via the National Sustainability program, from grants BD 2023-2025, FEKT-S-23-8425. For the actual analyses and experiments, the infrastructure of the IET was utilized.  
Data Availability Statement: Data are contained within the article.  
The authors declare no conflicts of interest. The funding organizations had no role in the concept of the study; in the collection, analyses, or interpretation of the data; in the writing of the manuscript; or in the decision to publish the results.