An intercom telephone is a special kind of telephone that controls a school or an office buildings intercom system. For example, with that telephone, the employers make the school announcements and can call each classroom's intercom by dialing the room number of that classroom. It can be interfaced with the building's access control system.
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Build an Intercom using two old Telephones - This video will describe how to build an intercom using old telephone sets. A battery, resistor and a wall phone jack is all that is needed. Parts needed: 9 volt battery 330 ohm 1/2 watt...
- Courtesy telephone
- Speaking tube
