such as slide switches and pressure switches as shown in fig9 the keyring lock 80 includes hub 84 operatively connected to a coil spring 82 which is in turn operatively connected to hub 42 of power source frame 22 it should be understood that many types of springs can be used to bias the keyring lock including coil springs leaf springs and u shaped or plastic springs to name a few the coil spring may be a separate component or may be made integral with the power source frame spring 82 exerts a force to bias keyring lock 80 to pivot outwardly and about post 40 the keyring lock 80 is preferably adapted to pivot about post 40 for only a limited distance keyring lock 80 further includes a stop 86 that abuts the power source frame 22 to limit the travel of the keyring lock 80 preferably the stop 86 prevents an outer edge 88 of the keyring lock to travel beyond the position where the edge 88 is parallel to an edge 89 of the power source frame other keyring locking mechanisms could be used having other forms of springs or resistance to bias the keyring lock alternately the.