Four weeks ago, in March, I received a request to deliver a few Ericofons and some additional equipment for an installation on an exhibition. As the exhibition still needs to take place, I cannot tell too many details right now so more news will follow next month.
Actually 2 landline phones can be easily connected to eachother with a battery and some electrical components to function as an intercom. No external telephone line is needed to provide a full speech path through both phones.
The challenge was to have both phones equiped with a decent ringer. Since the original ringer is functioning on AC and the voltage with batteries is DC, it cannot be used. Fancy electronic circuits are too vulnarable towards the input voltage so an interval piezo buzzer was the most stable solution. Sound wise it is somewhat annoying, but given the deadlines of this project it was not possible to develop something fancy custom made. As the piezos did not fit into the Ericofon shell I had to mount them on the outlet. The advantage is that the Ericofon is fully original and ready to be used for normal usage as well.
How it works: you pick up one phone and the other one is ringing. If the second phone is lifted the ringing stops and you can talk to eachother. And of course this works in both directions.
As the exhibition is abroad, I am in fact the remote viewer in this whole exercise. Unfortunately there is no way for me to visit the fair and to see the installation live. Not sure how all will look like. I’ll have to wait until someone sends me some pictures of the end result, which I hope I can share here.