Abstract: A self-contained alarm signal apparatus is disclosed which comprises an electrical signal generator, and encoder connected to receive the output of the generator and to encode a message to be delivered to a transmitter, a source of stored mechanical energy, and connector means for intermittently applying energy from the energy source to the generator for production of an electrical signal. Also provided are first and second input devices for delivering mechanical inputs to the connector means, each of the mechanical inputs operative to cause the connector means to apply energy to the generator. The first input device comprises manually actuable means and the second input device is automatically operable and comprises a timer and means to deliver a mechanical input to the connector means at predetermined time intervals.