Zollner - Model ZET-90 AC -Horn

The ZÖLLNER ZET-Horn was the first piston type whistle on the world market driven by an AC 3phase motor. An essential component is the piston inside the cylinder driven by an AC 3phase motor via connecting rod, crankshaft and gearwheels. The piston oscillates at a certain frequency which makes the air inside the sound horn vibrate in resonance to produce a sound audible over a wide range.