Abstract: An electrical switch device comprising a bi-stable double-throw switching relay having magnetic or mechanical means for contact holding, and at least one capacitive and/or inductive energy storing component to supply the switching relay with trailing edge trigger. The energy storing component is connected to a first contact of the relay, receives energy while the first contact is selected or reset and while the common contact of the relay is connected to a direct-current power source, and it discharges energy upon disconnecting the common contact from the power source so as to drive the relay, resulting in a second contact being selected. Such a switch device permits only the first pulse to reach the first relay contact after reset.