Electro-acoustic transducer

An electro-acoustic transducer, comprising:

• a frame with an accommodating space defined therein and an opening opened in a top surface thereof;
• at least one driving unit equipped in the accommodating space of the frame;
• a diaphragm movably mounted at the opening of the frame;
• at least one fulcrum settled in the accommodating space of the frame;
• and
• at least one lever placed next to the fulcrum to contact with and use the fulcrum as rotation center thereof, the lever connecting with the driving unit and the diaphragm at two ends thereof and transmitting vibration wave from the driving unit to the diaphragm, the lever having a longer length from the fulcrum to the diaphragm than from the fulcrum to the driving unit for increasing the vibration stroke of the diaphragm during transmitting the vibration wave;
• wherein the driving unit includes a U-shaped bottom plate fixed to the frame, a field magnet placed inside the bottom plate, a washer placed at the bottom of the field magnet to clamp the field magnet, and a voice coil movably mounted between the washer and the bottom plate and connected with an external signal source, the radius of the washer is smaller than the radius of the bottom plate, so a cylindrical gap is formed between the washer and the bottom plate, and the voice coil is axially movable along the cylindrical gap.