Upgrading unit for electrical signalling apparatuses

摘要

An upgrading unit for electrical signalling apparatuses, in particular for key-operated ring apparatuses which are connected to a voltage supply, is improved in that, when a signal is input by means of a signalling element, a return signal is carried out as speech information. For this purpose, a circuit, which has a digital store (memory) is connected to the two terminals of the signalling element, which circuit is activated to reproduce stored speech information when the signalling element is actuated or is triggered (Figure 3). <IMAGE>