The paper analyses the issue of functioning in the vicinity of the resonance of the mechanic equipment and/or devices with excitation sources the maximum perturbation force of which may be constant or variable related to the squared excitation pulsation. In both cases, the dynamic system does not remain constantly, stably and stationary on resonance point, the technological functionality being characteristic only for the ante/post-resonance regimens. For this reason, the proper notion of functioning in the vicinity of the resonance is used. There are dwelt with two distinct cases in this context, for a real dynamic model, from where it results the manner, we have to evaluate the maximal dissipated energy and maximal dissipated power related to the resonance regime. In both cases, the monotone increasing variation of the excitation pulsation requires contribution of energy from the source at the passage from ante-resonance to resonance or from resonance to post-resonance.