Relaxation oscillators can usually be represented as a feedback system with
hysteresis, The relay relaxation oscillator consists of relay hysteresis a
nd a linear system in feedback. The objective of this work is to study the
existence of periodic orbits and the dynamics of coupled relay oscillators,
In particular we give a complete analysis for the case of unimodal periodi
c orbits, and illustrate the presence of degenerate and asymmetric orbits.
We also discuss how complex orbits can arise from bifurcation of unimodal o
rbits, Finally, we focus on oscillators with an integrator as the linear co
mponent, and study the entrainment under external forcing, and phase lockin
g when such oscillators are coupled in a ring.