Motorcycle horn is a major safety signals means audible signal to alert pedestrians and other vehicles.

General use on the motorcycle electromagnetic vibration speaker, and there are two kinds of DC and AC. DC horn work, use contacts off. Current intermittent, alternating suction move or release the armature, which led to the vibration plate and the resonant piece, loud voice. AC horn work, the use of alternating current, alternating suction armature movable or release, thus boosting the vibration plate and the diaphragm vibration and sound. DC motorcycle horn structure as shown below, JH70 type, CY80 motorcycle pair are used ridicule such a structure.

When the horn button is pressed, the current through the contact to the coil. The electromagnetic force generated by the coil current fixed and dynamic vibration absorbing piece together armature. The downward movement of the armature, the contact arm and oppression make contacts open, current coil immediately disappeared, the armature itself under the force of the vibrating plate is returned, once the armature return, contact connected again. This constant rate to the audio back and forth vibration, resonance resonator pronounce sheet, and an audible signal of about 100db.

Some mopeds because without a battery, using AC horn, its structure shown below. When Magneto alternating current to flow through the speaker coil, soft core repeatedly in an alternating magnetic field under the action of pulsed electromagnetic force, intermittent suction movable armature. So the vibrating plate in the electromagnetic force and the elastic force itself constantly back and forth vibration and resonance pronunciation sheets, while a loud audible signal.

Motorcycle engine speed due to the impact of exchange horn sound frequency that is unstable its sound effects, at present, tend to use more current speakers. However, AC horn structure is relatively simple, without a direct contact mechanism that horn, and thus on the moped without batteries, has been widely used.