  Electromagnetic relays and solenoid actuators are commonly used for their
bistable behavior, which allows for switching between two states in electrical,
pneumatic, or hydraulic circuits, among other applications. Although there has
been extensive research on modeling, estimation, and control of these
electromechanical systems, a gap remains in the analysis area. This paper
addresses this gap by presenting an equilibrium and stability analysis to gain
deeper insight into their bistability. This analysis leverages a hybrid
dynamical model to obtain analytical expressions that relate the physical
parameters to the switching conditions. These expressions are useful, e.g., for
fundamental understanding, quick analyses, or design optimization. The results
are discussed in depth and potential practical applications are explored.
Finally, the analysis is validated with experimental results from a real
device.
