a Mini Phone (MIN318E)

  This assembly is ideal for an initiation work or science in the fundamental course, because it uses only two components that can be pre-prepared by the teacher.

   Common speakers and piezoelectric tweeters also work as microphones.

  Both generate small currents when the sound strikes your diaphragm and this current can be transmitted to an equal remote unit that will reproduce the sound.

   Thus, it is enough to connect two tweeters or speakers as shown in figure 1 to have a simplified communication system.

   Figure 1 - Connecting the speakers

In the case of piezoelectric tweeters we will have higher efficiency if we remove the small internal transformer that is destined to impedance matching, as shown in figure 2.

   Figure 2 - Removing the Transformer | Clique na imagem para ampliar |

We then connect the wires directly to the transducer.

   The wires linking the two stations can be up to 100 meters long.

  The system does not require any power source.